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Old 4th March 2021, 08:55   #1
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Default My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Introduction

I’d left you with Part-1 of my Pajero Sport story here (My pre-owned Mitsubishi Pajero Sport | Love it or Loathe it?). Now comes Part-2 as promised.

Quick Recap

I got a used 2012 Mitsubishi Pajero Sport in Aug-2019 with the odo at 1,36,800km. After the first few months of bliss, I suffered a scare when the car overheated en-route to Mumbai in Nov-2019, but managed to undertake the trip and return to Vadodara, although with multiple stops. The car was then driven at 70-75kmph to Surat to my old garage , where the radiator was serviced and a fresh batch of coolant, added. Post this, the car ran trouble free until Jan-2021.

Jan-2021 – Overheating ghost returns with a vengeance at 1,43,300 km

I had shut the car down in end-October 2020 and left the car idle with the battery disconnected for close to 70 days until I returned in Jan-2021 after a camp down south.

Arrival in Vadodara - Day 0

I obviously wanted to start the Pajero Sport up the day I arrived, and went about my process as follows:

1. Checked the coolant level, engine oil level and quality, and performed other visual checks to verify that there was no damage to wiring or other components. (It was winter and rats go bonkers on standing cars in winter. I speak from experience)
2. Connected the battery negative cable back
3. Started the car and she fired without any fuss
4. Ran the vehicle at idle for a while and then went and filled up some fuel (approx. 8 litres). The fuel gauge showed a little less than 1/4th tank before I filled 8 litres

The start up and the subsequent drive were uneventful (as in the clip below) and the car drove normal, like how she would drive before I shut her down in Oct-2020.



Day 3

It was again normal operation and I drove the car 40 km without any issues.

Day 11

The car started up normal but, strangely, began overheating exactly the same way she did in Nov-2019 viz. after approx. 15km in the city. I was able to return home but something told me that this was worse than what I had experienced in Nov-2019. The change in behaviour this time was that while the engine would pull clean at cold, the engine would get sluggish when the coolant temperature rose to normal operating level viz. 50%.

I was advised by a diesel car mile muncher to use System D to supposedly get rid of gunk that might have developed in the fuel tank due to the long period of non-usage. I added approx. 20ml of System D into the tank which contained approx. 20 litres of diesel.

Days 12, 13, 14

The start up on each of these days showed the exhaust getting smokey, and a characteristic lash being heard as in the clips below





On Day14, exactly seven minutes after engine start up as in the clips above, the engine idle went unstable as described in the following clip.



Other observations

1. The engine would run absolutely normal with non-smokey exhaust when raised to 2000 rpm
2. A sudden acceleration thereafter to say 3000 rpm would result in a momentary dark black smokey exhaust with a very pungent odour
3. Bring the engine back to 2000 rpm and the firing would be normal
4. Take the foot off the accelerator and the idle would be unstable with a smokey exhaust as described in the last clip above

This behaviour was also accompanied by the engine overheating in less than 5 km, necessitating a quick return to base.

Day15

No different from Day14, but this time, on my return after a 5 km drive, I once raised the engine rpm in second gear to 3500 rpm and could feel one cylinder shutting down and the engine going very very sluggish with vibrations

Day16

I had almost decided to take the car to Surat since I was quite sure the car’s coolant temperature would hover in the 70% range when on the highway at 60-70 kmph, but providence had other plans. When I opened the radiator cap, I discovered that I needed to add close to 1 litre of coolant in the radiator. This could have been because the earlier day, a lot of coolant had boiled over by the time I returned home.

Start up was a delayed affair this time, the car had virtually no power to move, and I knew that the car needed immediate attention.

Last edited by vigsom : 4th March 2021 at 20:33.
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Old 4th March 2021, 09:10   #2
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Emergency search for the right FNG

Knowing that the situation was deteriorating and the car might not make it to Surat, I decided to seek help in Vadodara than be stuck in the middle of nowhere on the highway. It was then that I remembered that someone in my apartment had sung praises about an old FNG in Vadodara called Kedar Automobiles. I went over to Kedar's with the reference, and the owner and the manager at Kedar’s were quite responsive. The owner, an automobile engineer himself is hard of hearing and cannot speak too, but understood the issue. Although Kedar has such limitations, he is gifted in his ability to assess cars and diagnose issues. They came over, did an inspection, and took the Pajero Sport away assisted by an Opel Astra of 1997 vintage. They suspected something wrong with engine compression but seemed very confident about sorting the issue out. All they asked for was some time as this could not be rectified in a hurry.

It was a rather embarrassing situation for me, as this was the first time in my automotive journey of over two decades that any car that I owned could not move on its own steam to a workshop and needed assist. I was fuming, disappointed, cursing Mitsubishi and what not for being let down like this.

Coincidentally, the same evening, I came across this TSB from Australia, and made me wonder if this same issue had cropped up in my car. Mine was a 2012 Pajero Sport, and I was not willing to digest the fact that a true blue Japanese conglomerate could be so poor at Quality Assurance.

Technical Service Bulletin(TSB)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_tsb.jpg

Inspection of the engine and accessories

The long and arduous journey of fixing the issues on the Pajero Sport started on 25 Jan 2021; let us call this ProjectPS_Day 00.

I did not want to go and snoop on the folks at Kedar’s workshop, but wanted to use this opportunity to list down all items that needed to be inspected. This overheating episode also presented me a scrumptious opportunity to add to my long years of automotive experience. Here is a long list of items that I marked for inspection:

1. Injectors inspection and service
2. Tappet cover gaskets, seals (the Pajero Sport tappet cover has a main tappet cover gasket, four smaller gaskets, four seals at the injectors top, and four seals at the injector inlet joints
3. Fuel filter
4. Cylinder head and associated components – camshafts, valves, rockers, seals, seats etc.
5. Timing and balancer belts with associated tensioners, idlers, timing tensioner adjuster
6. Radiator inlet tank repair/replacement
7. Thermostat inspection
8. EGR cooler and EGR valve cleaning
9. Intake manifold cleaning
10. Diesel piping to/ from High pressure pump inspection and cleaning (if required)
11. Engine oil replacement
12. Coolant replacement
13. Brake fluid replacement
14. Disc rotors skimming

Last edited by vigsom : 4th March 2021 at 09:12.
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Old 4th March 2021, 09:52   #3
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ProjectPS_Day 00-07

I would go to Kedar’s every alternate day for 2 hours just to note the progress made. Since the workshop sees a good inflow of cars, it wasn’t possible for one person to be working full time on the Pajero Sport, but I did see some traction day-on-day. The radiator, main viscous clutch driven fan, fan pulley, timing belt cover, air filter assembly, and the intake assembly were all off by Day 04 viz.29 Jan. The tapper cover, injectors, fuel lines, camshafts and cylinder head were off on Day 07.

Intake manifold removed
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_intakeremoved_29jan.jpg

Intake manifold with the EGR valve attached
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_intake_beforeclean1.jpg
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_intake_beforeclean2.jpg

Side view of engine with intake manifold removed - note the EGR cooler
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_day4_4.jpg

Top view of the tappet cover(note the injectors inlet connections)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_day4_8.jpg

Viscous clutch driven main fan
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_day4_11.jpg

Observations:

1. The timing and balancer belts looked in good shape but the timing idler pulleys were on their final leg. Same with the balancer tensioner. The only two good components were the timing tensioner and the timing tensioner adjuster

Timing belt in front and smaller balancer belt behind
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingbalancerbelts.jpg

Timing idler pulleys (one red and one blue)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timing_idlers.jpg

Timing tensioner (the part with the number on it)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingtensioner.jpg

Timing tensioner hydraulic adjuster (the one with the NTN stamp)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingtensioneradjuster.jpg

2. The cylinder head showed pitting between cylinders 1 and 2 and it is surprising how the engine was operational in this state
3. The pitting had also caused some damage at the seat of one intake valve and one exhaust valve on cylinder no.2
4. Cylinder head gasket was also damaged at the point where the pitting was seen
5. Injectors were found to be in order, and it was decided to just keep the tips soaked in diesel.
6. No damage was observed on the cylinder walls or any of the pistons
7. Water pump and turbocharger were observed to be fine

Cylinder Head top with camshafts
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_withcamshafts.jpg

Cylinder Head bottom just after removal
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headbottombeforecleaning.jpg

Cylinder head after preliminary cleaning for inspection - note the pitting between cylinders 1 and 2
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_afterfirstcleaning1.jpg
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_afterfirstcleaning4.jpg

Side view of the cylinder head exhaust side
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_sideview.jpg

Side view of the cylinder head - inlet side
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_sideview2.jpg

One Injector after removal
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_injector.jpg

Engine block with damaged head gasket
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_engineblock_damagedheadgasket.jpg

Engine block with head gasket removed
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_engineblocknpistons1.jpg

7. All parts were placed on a rug in the boot, to ensure that the boot mat wasn’t soiled – very thoughtful action by the technician.
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_partsinboot.jpg

Last edited by vigsom : 4th March 2021 at 20:02.
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Old 4th March 2021, 10:32   #4
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ProjectPS_Day 08-22

The cylinder head was cleaned, the pitting repaired, the head polished and returned by the evening of Day10 (within 72 hours) with tappet clearances set at the stipulated values. Although I gave them the values of 0.09mm for the intake valves and 0.14mm for the exhaust valves, I did not personally check the final values and trusted the many years of experience of the head expert to set the clearances. The surface of the block, was, meanwhile polished and the top of the pistons, cleaned.

Cylinder Head bottom - before vs after
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headbtm_beforevsafter1.jpg

Cylinder Head top - before vs after
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headtop_beforevsafter1.jpg

Engine block - before vs after
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_block2_beforevsafter1.jpg

Sourcing of parts

I was keen to do the sourcing of parts myself but Kedar wanted to take the onus on himself. He wanted to be sure of what he was ordering, and through his trusted suppliers with whom he had a long term relationship. So, while I wanted to be the conductor of the show, all I ended up was being a pianist !! I thought long and hard and decided to let the onus rest on him as one wrong part delivered and they wouldn’t stand guarantee to their work.

Timing Kit

The timing and balancer belts were in good shape and looked to have been replaced at the 1,10,000 -1,20,000 km mark. However, the idler bearings and the balancer tensioner needed to be changed as they had begun to show signs of wear. Kedar opined that it was a good idea to replace the belts and the faulty components as this was an opportunity. This would ensure that the timing kit is good for another 1,00,000km. However, we realized that the timing idler pulleys and the balancer tensioner weren’t sold separately, and therefore had to go for the full kit.

Preliminary enquiries showed this complete kit (belts, pulleys and adjuster) to cost a bomb at Mitsubishi. However, the two belts (Timing belt and Balancer belt) were available as separate items and the rest (timing idlers, timing tensioner, timing tensioner adjuster, and balancer tensioner) was available as a set separately with some suppliers. Here again, Kedar took the onus, and eventually sourced a Dayco timing kit and a Dayco balancer kit, all for a very competitive INR 16,500.

Timing and balancer belts
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingbalancer_belts.jpg

Timing idler pulleys, tensioner and tensioner adjuster
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingkit_new.jpg

Drive belt
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_drivebelt.jpg

AC Compressor belt
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_accompressorbelt.jpg

Last edited by vigsom : 4th March 2021 at 15:08.
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Old 4th March 2021, 10:53   #5
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

ProjectPS_Day 08-22(Contd.)

The dilemma on which head gasket to procure

I had, in the meanwhile,

1. sourced the parts catalog for this car on partsouq, and
2. downloaded the service manual for a Mitsubishi L 200 from the net

The information presented therein added to the prevailing tension – there were six types of head gaskets on the catalogue and in the service manual, and the manual clearly stated that the replacement gasket should be the same as the one that came out of the car. In the case of this Pajero Sport, the gasket was marked D5-998, viz the three hole ID gasket marked under Euro5 in the manual.

Head gasket IDs listed in the catalog
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headgasketid.jpg

Extract from the service manual
Name:  PajeroSport_servicemanual_extract1.jpg
Views: 8024
Size:  169.4 KB


Head gaskets available

On floating an enquiry for gaskets, the following information was received

1. D5-207 three hole gasket for approx. INR 5,000 plus shipping
2. D5-998 three hole gasket of the exact identification as in the car, but the quality of fit and finish wasn’t reassuring. One quote was for INR 6,800 plus shipping and another was INR 8,200 plus shipping.

To the left is the stamping on the new gasket and to the right is the stamping on the gasket that came out of the car - note the difference in quality of stamping and metal
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_availablevsoriginalgasket_identificationstamping.jpg

Sample Original gasket_image sourced from overseas - zoom in to see the quality of metal and the stamping
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_oegasket_sample.jpg

A source at Mitsubishi known to this workshop was quoting some insane rates for the MMC original head gasket, and they refused to share pictures unless the money was paid. Kedar’s, in the meanwhile, sourced a gasket manufactured by Eristic, and claimed that it was extremely good quality. It was indeed impressive quality but had no tag stamp on it. This was offered at INR 6,500 but I was in no mood to give clearance for this gasket to be used as I wasn’t sure if it matched the thickness of the original.

Decision making on the Cylinder Head gasket

The procured head gasket matched the specs of a D5-207, the same gasket that was being offered by a supplier in Delhi for 5 grand. I had to ensure that it was good to go. The only show stopper in approving this gasket was piston protrusion, because a gasket of a lower thickness should not result in valves inadvertently striking the piston top.

All of us (Kedar, his technicians and I) got down to

1. measuring the piston protrusion and found it to be negligible (well below the 0.23mm allowance specified in the gasket spec for D5-206), and
2. measuring the thickness of this new gasket against the old D5-998 and obviously found the new one to be thick enough to go.

Just for reference, the old gasket thickness was 1.05mm while the new one was at 1.8mm at the lowest surface. The collective experience of Team Kedar opined that this gasket would work perfect, and, armed with all the data collected this far, I gave the go ahead, hoping that it would turn out right.

New Eristic head gasket vs old
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headgasket_newvsold.jpg

New head gasket on the block
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_newgasket_onblock1.jpg
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_newgasket_onblock2.jpg

Last edited by vigsom : 4th March 2021 at 19:15.
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ProjectPS_Day 08-22(Contd.)

Days 14-22 was a rather slow week as three technicians were on leave and the technician working on the Pajero Sport had to attend to other vehicles too. However, the perfectionist that he was, he took time to do all that he could for the Pajero leaving no stone unturned. The tappet cover, the EGR cooler, the intake manifold, the EGR valve, the fuel piping, were all cleaned thoroughly and kept ready for assembly. Operation of the thermostat was verified by putting it into a pan of water, on an induction stove and watching at what temperature the valve opened.

Injector tips had been dipped in diesel for three weeks and body of the injector, cleaned just prior to fitment. Also seen is the injector fuel return manifold. The injector return manifold in this car lies under the tappet cover, and hence it is very important to align the manifold right with the injectors, and then tighten the joints. This is to prevent inadvertent leak of diesel from the manifold joint into the oil chamber.
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_injectors.jpg

Clean Tappet cover - note the main gasket, several small gaskets and seals
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-20210211_154222.jpg

Tappet cover before vs after cleaning
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_tappetcover_beforevsafter1.jpg

Intake manifold after vs before cleaning
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_intakemanifold_aftervsbefore.jpg

EGR Cooler before vs after cleaning
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_egrcooler_beforevsafter1.jpg

Water Pump
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_waterpump1.jpg
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_waterpump2.jpg

Thermostat closed
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_thermostat.jpg

Thermostat partly open immediately after checking
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_thermostat_operationcheck.jpg

New radiator
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_radiator.jpg

Note on the radiator :

1. Some aftermarket radiators come with a straight joint at the outlet as shown in the following pic. There is no room in the Pajero Sport to accommodate a hose that can fit a straight joint. Hence, please go only with an elbow at the bottom.

2. The radiator for a AT Pajero Sport will have two nozzles for hoses to and fro the transmission cooling. If anyone uses this radiator on the Pajero Sport MT, please have a bypass hose installed across these nozzles OR have the nozzles blanked off.

Radiator with a straight hose joint at the outlet (won't work)
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-20210216_125628.jpg

Last edited by vigsom : 4th March 2021 at 19:31.
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ProjectPS_Day22-28

Assembly

The head was fitted back on its eighteen bolts in a sequence, and all the other items were assembled. Let the pictures do the talking.

Extract from the service manual indicating the order in which cylinder head bolts need to be tightened
Name:  PajeroSport_servicemanual_extract1.jpg
Views: 7609
Size:  169.4 KB

Balancer belt and tensioner installed - note the timing marks on pulleys in pink aligned with the relevant marks on the body
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_balancer_timingmarks.jpg

Cylinder head installed. The head has to be installed first, then the cylinder head bolts tightened, and then the camshafts and connected oil headers need to be installed.

Cylinder head in position
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_inposition1.jpg

My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_headinposition2.jpg

Camshafts placed and aligned based on the marks encircled
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_dohcalignment.jpg

Camshafts, oil headers and injectors in position
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_injectors_camshafts_piping.jpg

Injectors with injector fuel return manifold in position
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_head_injectors_piping.jpg

New timing kit installed - note the timing mark on the camshaft pulley
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_newtimingkit1.jpg

Timing mark on the crankshaft pulley in pink
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingmark_crankshaftpulley.jpg

Timing mark on the HP diesel pump pulley
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_timingmark_hppump_pulley.jpg

Fuel injectors inlet line priming

This operation needed to be performed before the intake manifold installation so that access to the fuel injectors inlet joints is possible. During this activity the injectors’ wiring couplers should not be connected.



Assembly (Contd.)

Awaiting installation of the intake manifold, power steering pump, fan pulley, timing mechanism covers
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_awaitingmanifoldinstallation.jpg

Oil cooler just below the oil filter was full of caked dust - cleaned
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_oilcooler1.jpg
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_oilcooler2.jpg

Close-up pic of the diesel high pressure pump. The 1" diameter shiny corrugated cladded hose that you see is the exhaust gas recirc. to the EGR Cooler inlet.
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_dieselhppumpcloseup.jpg

Assembly almost done, waiting for the radiator to be installed
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_assemblyalmostdone.jpg

Engine ready to fire
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_readyforstartup.jpg

Last edited by vigsom : 4th March 2021 at 20:08.
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Moment of truth – Start up on Day 28

The technician working on the Pajero Sport was so supremely confident about the fitment that he nonchalantly asked Kedar to fire the car up and then hold the engine at 2000rpm. The car started up in a flash with no hiccups, and it was a huge relief to all of us.



Trial run – Day 29

The car underwent a 40 km trial run on the highway at 100 kmph with the AC on, and never felt this smooth ever. The coolant temperature never crossed 50%. A surprising observation though ,was, that the fuel efficiency never went above 9kmpl during the the trial. However, over the last few days, the ECU and injectors have kept learning and the current fuel efficiency with AC at 90kmph is in the range of 12.2kmpl and still improving. I am sure it will get back to old levels.

Temperature gauge at normal temperature after the trial run
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_instrumentcluster_aftertrial.jpg

A clean engine bay
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_cleanenginebay.jpg

Expenses incurred in Major Inspection – Feb 2021

A: Cylinder Head

1. Cylinder head renewal INR15,500
2. Cylinder Head oil seals INR 5,500
3. Engine block top polish INR 2,500
4. Cylinder head gasket INR 6,500

Cylinder Head Sub Total A : INR 30,000

B: Timing and Balancer Kit (Belts, idlers, tensioners and tensioner adjuster) INR 16,500
C: Radiator INR 16,500
D: Drive belt and AC compressor belt INR 1,700
E: Engine Oil (Mobil Super 1000) plus oil filter (Sakura) INR 3,000
F: Labour charges – EGR Cooler, EGR valve, tappet cover, injectors cleaning plus engine top disassembly and re-assembly INR 15,000
G: Brake rotors removal ,skimming,refitment and brake fluid replacement INR 2,600

Grand Total : INR 85,300

This might look like a steep expense, but I’d say it was money well spent. I saved a potential INR 5,000 minimum because the injectors didn’t need to be serviced, plus at least INR 5,000 on the Dayco timing kit. The new radiator was my only grouse because I was fully convinced that the minor deficiency in construction of the old radiator could have been rectified. However, since I had factored this expense in at the time of negotiating on my purchase price, I’ll discount that too.

Last edited by vigsom : 4th March 2021 at 19:40.
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Old 4th March 2021, 12:29   #9
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Failure Analysis

It is clear that the overheating was on account of hot gas breakthrough from the combustion chamber into coolant. What foxes me, however, is how this engine was operating with the pitting on the head between cylinders 1 and 2, and why the pitting actually took place. I have always kept a close watch on coolant levels. Pitting has occurred over a period of time and is not a sudden development.

Here are some possible causes, and some arguments against each:

1. Hi-power engine – the engine in the Pajero Sport is a high torque (400Nm) avatar of the old 4D56, which has seen non-turbo variants and then turbo variants over almost 3 decades. I have seen Pajero Sports that have done 2,00,000km plus and going strong even without even a timing belt replacement. Could the 400Nm torque be responsible? Can't say and I don’t believe that the legendary Mitsubishi could have committed such a blunder as to not design the engine and the cooling system appropriately

2. Hard driving by the earlier owner’s driver – from my experience, I can say that this car has so much torque that it need not be pushed hard to achieve highway speeds of typically 120-140kmph. These SUVs are anyways abuse friendly.

3. Momentary loss of coolant during the minor shunt that this car had faced – if you recall, I had mentioned about this shunt in my ownership review and it is possible that the driver drove on even with the radiator leaking. The way the car was kept by the first owner doesn’t seem to suggest this act of negligence, but this can't be ruled out either. This must have triggered the first damage to the head. Yes, the empty coolant expansion tank during my initial evaluation must be viewed as a tell-tale sign of minor overheating, because I have never seen a single car losing so much coolant from the expansion tank if the cooling system were working normal

4. Improper monitoring of coolant levels by the driver of the first owner – again, possible, especially post the shunt. I know that most drivers are generally a casual lot, especially in GJ

5. Cramped cooling air path in the Pajero Sport – not much room for heat dissipation, plus the Technical Service Bulletin says it all – that overheating has been experienced in several pre-2014 cars.

There is a you tube channel called Noah’s Garage, where the owner has a low run Mitsubishi Montero Sport which sports the same engine. His car hasn’t done even 30,000km and he faces minor overheating issues. There are a few other videos too featuring overheating on some Pajero Sport specimens.





Recalling a few observations on my car :

1. If I think hard and do a memory recall of how the car behaved from Nov-2019 till date, I do remember a few drives between Sep-2020 and Oct-2020 where the engine would start up with a clatter/ tappet noise, but then stabilize after a few minutes
2. Also, when given sudden pep to accelerate from, say 60kmph in 5th gear, the gear lever would move violently from left to right for a few seconds to suggest that the engine was getting sluggish momentarily. This was never the case, at least till the car was being used regularly until 22 Mar 2020.
3. It is clear that the deterioration in the head had set in sometime earlier but not noticeable, became mild in Sep 2020, and worsened after the car resumed operation in Jan-2021 after a 70 day shutdown.
4. It is possible that during the 70 day shutdown in winter, the metal must have contracted and after the car started up, the head gasket and the head, that were already in average shape would have opened up a bit when the engine coolant temperature rose.

The car’s components are top notch but maintenance is not at all technician friendly.

Last edited by vigsom : 4th March 2021 at 20:00.
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Old 4th March 2021, 12:38   #10
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Actions to prevent recurrence

Since my Pajero Sport is close to 09 years old and at 1,43,500km on the odo, the only actions in my control are to clear the air path of as many obstructions as possible, and ensure that the radiator runs on a good coolant mix. A few actions listed here:

1. Relocate the two horns to locations where they don't obstruct air flow. I don't know if this will make a difference but believe that no mod should obstruct an air path, especially when the front of the AC condenser is already congested
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-20210304_161148.jpg

2. Move the HSRP a little up to ensure that the bumper bottom grille has its entire surface area open for air to flow in
My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it-pajerosport_frontview.jpg

3. I have already used superior long life coolant viz. Servo Kool Plus in a 50% concentration and that should ensure that there is no compromise on the heat transfer fluid

Acknowledgement

I would like to thank the entire team at Kedar Automobiles, Vadodara, especially the perfectionist technician Jabir, who ensured that every possible care was taken during the diagnosis, solutioning, execution phases which all culminated in a smooth start-up of the car. Yes, it was a long drag of 28 days, but the good thing is that the car is performing even better than in 2019.

Closing Comments

Most people in my place would have given up on the car after this episode, done up some basic work, and put the car up for sale. I’m the type that doesn’t follow the calf path. This car has demonstrated its many virtues, has held up quite well despite the overheating episodes. Even when the exhaust was smokey and one cylinder had shut down, the car kept going without even a check engine light coming on. The Pajero Sport has been an epitome of exhilaration, and this episode has provided me with a phenomenal learning opportunity. I can safely say that this episode has de-mystified the Pajero Sport for me.

If you look at the expenses closely, the Cylinder head component was the only unscheduled expense and that was a hit of only INR 30,000 for the head and INR 15,000 on labour; much lower than what most would pay for scheduled maintenance for a car this age and this odo reading in this period of ownership. Yes, spares are a little more expensive than competition (read Toyota), but that is not a downer. One has to, however, guard oneself against greedy suppliers who use the Mitsubishi, and the Pajero name to fleece customers.

I am keeping the car for as long as I can, and would like to re-live the good times as a lot of time, money and effort has gone into bringing this fella back to old glory !!

Last edited by vigsom : 4th March 2021 at 20:31.
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Old 5th March 2021, 05:03   #11
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Default re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Thread moved out from the Assembly Line. Thanks for sharing!
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Old 5th March 2021, 09:41   #12
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Default Re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Hi Vigsom!

I think it was the minor shunt that the car went through which caused this. Long back, A friend’s WagonR went through something similar. We had to eventually do an engine overhaul. I have two experiences two share on similar lines-

1. We were evaluating a Figo diesel for a relative. A low run diesel but the owner had the service records. Now this car was involved in a pileup crash in Kolhapur. The repair work was carried out at the ford svc. I could see the replaced bonnet support and bonnet. Saw the bill and realised extensive work was done. Fortunately the apron, engine and gearbox were untouched. The car was towed away from the accident spot to the svc. The boot was replaced too. Overall a well kept car. The work was done at the svc and all those parts had taken brunt which were supposed to take it in any accident. We got the car eventually.

2. While evaluating this Figo, we came across an Amaze diesel. The paint mismatch was a giveaway and I later found that the bonnet was replaced with a second hand piece and painted in a shoddy manner. The bonnet support was repaired and was already rusting. The AC would cut off in between and even thought car was serviced 1k kms back at Honda, the oil level was low. Ironically this car had a higher rating on an aggregator’s website. They always feel like a joke to me.

I think minor shunts which don’t damage the structure are fine but what’s important is how they are repaired. I think you are lucky because you were able to identify the damage before it worsened. It’s no rocket science that Mitsubishi parts are expensive but their quality is phenomenal. One of my friend’s dad bought the PS when he was 60 years old and drives it like a teenager. He loves the car so much that he has asked his driver to do duties at home. This particular car has done over 200k kms and mostly driven hard. I don’t think it’s the 400NM or hard driving which can cause this. These cars are built to last. Please run in the engine again and do consider getting a nice remap after 20k kms. Happy mile munching!
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Old 5th March 2021, 10:56   #13
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Default Re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

Totally worth the wait for this part 2.

How do you check the quality, Sir? what should one look out for?
Quote:
Originally Posted by vigsom View Post
ProjectPS_Day 00-07
1. Checked the coolant level, engine oil level and quality,
From which exact place did the gases meet the coolant?

Quote:
Originally Posted by vigsom View Post
Failure Analysis

It is clear that the overheating was on account of hot gas breakthrough from the combustion chamber into coolant.
I read through every inch of this thread and thoroughly enjoyed it! And it taught me so much. Thank you for these quality threads on the forum.

Seeing you maintain high mileage cars so well purges the fear of old high run cars from my mind! I can only imagine the feeling of a completely repaired engine, must feel amazing! Wishing you many more happy kms in this baby!
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Old 5th March 2021, 11:19   #14
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Default Re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

What a journey it has been. It's hard to imagine what started off simply as what we suspected to be a pinhole leak in the EGR cooler assembly eventually turned out to be the mother of all overheating issues. The most surprising part as you mentioned too, was the fact that the Pajero Sport continued to run with low compression on 1 and 2 without much of an issue at all.

There are a lot of takeaways from this experience. The biggest one of all is that there's always a way out of every automotive problem. An issue like this would have seen the average joe sell the car off for what it was worth, but I think your patience genuinely paid off in the long run. As you rightly said to me once, this was an exam in automotive fault diagnosis for you to earn your PH.D. As a person who has had firsthand experience of how you went about solving this issue, I think you have passed this one with flying colours.

Kedar is a very underrated character in this entire episode. Having seen him personal and up-close and the way he works, I was left impressed. The same goes for Jabir. Having experienced 2-3 FNGs, one thing I can vouch for is that very few mechanics have the attention to detail coupled with the skill set he had. Every mechanic makes a decision that can turn the situation for the good or for the worse, and Kedar was also forced to make a few of them.

- He could have simply asked you to overhaul the injectors looking at the black smoke the car was throwing out. But, he simply kept them dipped in diesel and saved you the hassle of overhauling a precision engineered part apart from money

- Sourcing an entire timing kit for 16.5K instead of simply going for 2 belts and a couple of pulleys was again unexpected. The Dayco belt came as a godsend considering how expensive the Mitsubishi timing kit was

- The Eristic head gasket was always a gamble for us, but I think Kedar was doubly sure it would work from the start. Again, this was a good call considering the wait for a new Mitsubishi gasket would be too much

All in all, his gut feeling and instincts were far more valuable than anything else to us.

It's good to see her back on the road. The engine feels just like new. Not a hint of misfire or lugging now. Very smooth idling, and top notch NVH as expected from the 4D56. Wishing you many happy miles ahead with your Pajero Sport

Last edited by vishy76 : 5th March 2021 at 11:21.
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Old 5th March 2021, 12:15   #15
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Default Re: My pre-owned Mitsubishi Pajero Sport | Return of the overheating ghost & solving it

One of the very few technical threads where I didn't skip a line Sir. That's my love for Mitsubishis.
Hat's off for your perseverance, like others called out an average joe like me would given up and sell off the vehicle.

I have been a Mitsu fan since childhood days and dreamt a lot bringing home a cedia sports, did check out couple of them but this was when I could barely afford it but yes continued to window shop.

My goal is to own a Pajero Sport (4x4) one day and reading your threads my dream has re-ignited. Your ownership thread has given me lot of information on the home work to be done before venturing out in the market.

Wishing you miles of happiness with the new transformation.

Will be glued to both your threads

Last edited by Abhi_abarth : 5th March 2021 at 12:16. Reason: Edits
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