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Old 13th October 2012, 09:12   #31
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Default Re: When it's time to overhaul the engine ?

It depends a little bit on what you mean by overhaul. I'd say you talk about overhaul when you pop the cylinder head of and take the pistons out.

Roughly speaking, reason to overhaul an engine petrol or diesel for that matter are:

1) excessive loss of compression
2) Scheduled maintenance
3) Experience / you just like to tinker with engines

On the first; There are different symptoms such as excessive oil consumption, irregular idling, loss of power etc.

As you (nearly) always start by taking the cylinder head first, some of these symptoms could be related to issues with the cylinder head / valves only. If it does, you're lucky, because you don't need to take anything else apart.

On item 2; these days, rare for cars, but there are probably still some cars around where there is a recommended manufacturer "overhaul maintenance". On Industrial diesels there are, in most case. I used to be in the merchant navy and during my 8 years as a ship's engineer I've overhauled a large number of diesel, based on recommended manufacturer running hours. In all those cases the diesels were running fine. So it's really a case of preventive maintenance.

These overhaul jobs were mostly about taking the whole engine apart, cylinder head, pistons, bearing etc, in some case pulling the cilinder linings. And then you start measuring everything very careful for wear and tear. e.g. pistion rings, bearings, valves, valve guides, springs, cylinder diameter etc. Everything that wasn't up to the manufacturer's recommended measurement got replaced.

On item 3; Quite a few posts already on this one. Some just feel it might be a good idea to overhaul an engine after a certain mileage. Or in my case, I also like to tinker with engines.

So when I bought my 1986 Alfa Romeo Spider I did a lot of work on it. Including a complete engine overhaul. Not because it was necessary. I bought it second hand, it had run about 90.000 miles. But I just enjoyed working on it and I wanted to make sure it would run well for a long time. And amongst Alfa enthusiast there was a general rule of thumb that at around 100 - 120.000 miles, it might be a good idea to overhaul the engine anyway. As they were prone to develop problems at higher mileages.

I owned a Jeep Cherokee and if you would visit their forums you will find that these will easily run up to and beyond 300.000 miles. And that's for a 4.0 liter, 6 inline petrol engine.

I own a Mercedes W123 and again owners will report very high mileage on petrol engines and even higher on diesels.

Jeroen
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Old 13th October 2012, 14:45   #32
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by 1self View Post
di1in,

Do a leak down test at a good garage & all your questions will be answered. I think if you de-carbonize your engine you will be satisfied.
Please let me know how much such a test would cost me.

Bangalore BHPians, could you guys kindly recommend a good mech, hopefully within 10 kms from PVR Forum in Koramngala?
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Old 13th October 2012, 18:22   #33
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by di1in View Post
Please let me know how much such a test would cost me.

Bangalore BHPians, could you guys kindly recommend a good mech, hopefully within 10 kms from PVR Forum in Koramngala?
This link is to give you an idea of the what the leak down test comprises.

http://www.carcraft.com/techarticles...r/viewall.html

The de-carb should not be more than Rs.1500-2000.
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Old 13th October 2012, 22:20   #34
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by 1self View Post
This link is to give you an idea of the what the leak down test comprises.

http://www.carcraft.com/techarticles...r/viewall.html

The de-carb should not be more than Rs.1500-2000.
Thanks for the link.

Just one question, will de-carbonzing an old engine cause problems related to leaks? I think I read this somewhere, but not sure if the cause was de-carbonzing or changing to synthetic from mineral oil.
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Old 13th October 2012, 22:51   #35
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by abhishek24x View Post
can anyone suggest when does a K12 engine (Maruti EECO) require an overhaul?? I'm getting an EECO which has done 140K on odo but the engine pulls nicely. So how do I know if the engine has some miles to munch or requires immediate overhaul?
I know of 2 cars which are doing superb inspite of having done close to 2 L kms . One is my mpfi Zen (2.06L kms) and the other is Parag Sachania's Wagon R (1.8L kms) . Both these cars compulsorily get their manufacturer specified servicing . Both these cars are also red lined regularly on long drives . Both these cars have never ever caused any issues till date

Now coming back to your question of a K12 engine , I am sure it would easily do similar ,if not more kms than the above mentioned cars which have less advanced engines. So , as long as there is nothing untoward happening , guess you shouldnt go overboard thinking about OH .

First thing you need is a reliable MASS
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Old 14th October 2012, 19:30   #36
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by di1in View Post
Thanks for the link.

Just one question, will de-carbonzing an old engine cause problems related to leaks? I think I read this somewhere, but not sure if the cause was de-carbonzing or changing to synthetic from mineral oil.
De-carb will let you see what problems you already have, which the hardened carbon deposits were covering up. Get the leak down test done after the de-carb.
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Old 14th March 2013, 11:16   #37
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Default Re: When it's time to overhaul the engine ?

Hi There,
I own a 2003 Mahindra BoleroGLX which has done about a lakh on the odo (I piked it up as a used car.So, the reading could have been tampered with).
I have a few problems with the car and have shown it to my regular meachanic as well as a few recommended by friends for
different opinions. All of them have suggested an "Engine overhaul".
Now, coming to the car's problems.
1.I have excessive smoke coming out of the Engine breather pipe. More so at idling.
2.Reduced acceleration from low speeds
3.Excessive consumption of engine oil. (I top it up for about 1L for every 1000km)
4.I have to heat up the glow plugs for about 3 times prior to cranking the engine on a cold start.
5.Reduced Fuel efficiency. About 8KMPL in city.
Do these symptoms suggest that I need an engine overhaul ?

Ok. if there is an overhaul done,I have the following questions:

1.Will the car's pick-up (acceleration ) improve post the overhaul ?
2.Is there any other supplementary job that needs to be done . Something like a gear box maintenance etc.,?
3.what is the kind of maintenance that would be involved post the overhaul ?
4.What is the cost that would be involved with an XD3P engine overhaul ?

Lastly, I live in Bangalore.
Could anyone who has got an XD3p (Bolero) engine overhauled speak about it and give me details as in the mechanic and the
work involved ?
This is my first post on this forum. Hope I will hear from an expert/fellow BHPian at the earliest.

Thanks !

Regards,
Sai
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Old 14th March 2013, 11:57   #38
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Default Re: When it's time to overhaul the engine ?

Quote:
Originally Posted by Sai Sudhir View Post
1.I have excessive smoke coming out of the Engine breather pipe. More so at idling.
2.Reduced acceleration from low speeds
3.Excessive consumption of engine oil. (I top it up for about 1L for every 1000km)
4.I have to heat up the glow plugs for about 3 times prior to cranking the engine on a cold start.
5.Reduced Fuel efficiency. About 8KMPL in city.
Do these symptoms suggest that I need an engine overhaul ?

Ok. if there is an overhaul done,I have the following questions:

1.Will the car's pick-up (acceleration ) improve post the overhaul ?
2.Is there any other supplementary job that needs to be done . Something like a gear box maintenance etc.,?
3.what is the kind of maintenance that would be involved post the overhaul ?
4.What is the cost that would be involved with an XD3P engine overhaul ?

Lastly, I live in Bangalore.
Could anyone who has got an XD3p (Bolero) engine overhauled speak about it and give me details as in the mechanic and the
work involved ?
This is my first post on this forum. Hope I will hear from an expert/fellow BHPian at the earliest.

Thanks !

Regards,
Sai
The engine emitting a lot of smoke and using a lot of oil sounds like your rings are gone. Given the various problems, it does sound like you need an overhaul or preferably a new replacement engine.

Once your engine is repaired (if done competently) it should get back to performing like a more or less new engine. Similar performance and mileage.

Sorry no idea about the costs involved.
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Old 14th March 2013, 13:22   #39
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Default Re: When it's time to overhaul the engine ?

Quote:
Originally Posted by Sai Sudhir View Post
Do these symptoms suggest that I need an engine overhaul ?
Quote:
1.I have excessive smoke coming out of the Engine breather pipe. More so at idling.
Yes, this is one of the symptoms. This means compression is leaking from the rings.
Quote:
2.Reduced acceleration from low speeds
Yes, this is also a symptom. Compression leak = low power.
Quote:
3.Excessive consumption of engine oil. (I top it up for about 1L for every 1000km)
Sadly yes, this is also a symptom, that points to engine rebuild.
Quote:
4.I have to heat up the glow plugs for about 3 times prior to cranking the engine on a cold start.
Again, reason is compression loss.

Quote:
1.Will the car's pick-up (acceleration ) improve post the overhaul ?
Yes it will improve.
Quote:
2.Is there any other supplementary job that needs to be done . Something like a gear box maintenance etc.,?
May be you will need to service and calibrate your pump.
Quote:
3.what is the kind of maintenance that would be involved post the overhaul ?
If done properly, you can use it like an almost new engine after the run in period.
Quote:
4.What is the cost that would be involved with an XD3P engine overhaul ?
Approx 50k, with genuine parts.

Quote:
Could anyone who has got an XD3p (Bolero) engine overhauled speak about it and give me details as in the mechanic and the
work involved ?
I do not know good mechanics in Bangalore, but, one thing that I know and would like to warn you about is: XD3P engine rebuild should be done properly. I've heard and seen numerous XD3P rebuilds going bad, or rather not up to the mark.

So, if you want to use the car for a long time, PLEASE make sure the rebuild is done according to the factory spec.

P.S:- Some of the above mentioned issues, like starting and low pick up can also be sorted out by playing with the fuel pump settings. So, I'd probably advice that, before going in for a rebuild.
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Old 14th March 2013, 14:45   #40
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Default Re: When is it time to overhaul the engine ?

Thanks a lot Ganapathy and Dhanush for that prompt reply to my queries.
As per your comments,am quite certain that an engine overhaul is needed and the job would solve the issues that Ive mentioned in my previous post.

I hope I can find a fellow BHPian who knows a mechanic in Bangalore who can do a good job with this XD3P engine overhaul.

anyways, thanks again !
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Old 16th March 2013, 07:13   #41
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Default Re: When is it time to overhaul the engine ?

Read through this fine thread.
I would like to add a few things I learned from hobby jobs with engine ovehauls. I had bought an old 1989 Maruti 800 earlier for this purpose and had done three engine overhaul in quest for finer performance. Only the last one was somewhat meaningful.

Let me explain.

Engine overhaul is for cleaning off the carbon and changing piston rings to regain lost compression- this is perception we car owners share to varying degrees.

But I came to learn more of that is included in engine overhaul.

Most car engine overhauls are mainly changing the entire piston and
connecting rod assembly- I used not agree earlier [Typical marine prejudice], but working with the mechanics I have learnt from observation that the aluminum components are best discarded once removed for overhaul and replaced by new spares, because the fine wear down on the ring grooves and minor thermal deformation of the piston crowns can not be measured by the available workshop tools.

Much better , the liner block too should be discarded because the weardown and/or ovality are not possible to measure. Any re-use of liners and pistons will develop into performance loss later. Even separately purchased liners and pistons will have mating issues.

Maruti used to sell a half engine ie a set of pistons and liner block that is mated at the factory, I would expect many other manufacturers do provide similar combinations.

Crankshafts are better to retain , and only if need be there eg scoring on the journal pin surface etc, all because crankshafts are much more expensive.

The cylinder heads are expensive parts too but building and shaping the surface are quite reliable [ though the metal compatibility in repairs from local workshops are doubtfut and so is the heat treatment aspect, but in small cheaper engines I guess local repairs work OK].

Much of the post overhaul niggles come from faulty re-adjustment of timing of the camshaft. I have seen that in the small engines there is no timing mark on the gears. Maruti800 engine and I would like to belive, most modern passenger car engines use a
toothed flat belt type rubber timing belt. This is where mechanics tend to make a mistake in counting the belt teeth numbers [ before and after the overhaul].
One tooth mistake amounts to 2 to 5 degrees of change in the camshaft- the sore area of all post overhaul discomfort. In petrol engines I have seen mechanics try to compensate this offset by the advance/retd of spark timing, but the results are rarely as good as new. Any unnecessary advancing eventually damages the crankpin and main bearing though initially the owners are shown a more peppy or torqy engine [ falsely as a good effect of the engine overhaul]. I may not guess what is done in the larger diesel car engines, are thre gears or chains for timing?

One more area generally neglected as a cost cutting measure or simply the ignorance of the mechanics is the changing of the engine block holding down long bolts and the bolts of the crank pin bearing. These bolts are inevitably stretched longer due to prolonged use, re-tightening these even by tightening to the oem torqe value , does not offer the correct needed compression. In small passenger car engines the tolerance values are very minute, even 0.2 mm diffrence changes the compression height [ speacially including higher thermal elongation of old bolts] . Same applies to the Cylider cover bolts. All these finally affect the bumping clearance above the piston at TDC- the reason why workshop overhauled engine does not give the same feel of compression as new factory assembled engine.
Customer queries are often craftily diverted citing reasons about engine being set-in etc.

The point I am trying to emphasize is that full engine performance can not be restored by local workshop overhauls. At best we should perhaps look for 90%.

One more point I would like to mention is the quality of the spares. The oem spares are never as durable as the initial components, though no manufacturer would perhaps agree to this.

My first hand experience is of course very limited, just one M800 engine three times and a couple of 150cc two wheeler engine for hobby and one Scania DS14 engine [ abt 200KW] from work. That is all about automotive engines, which work on very fine tolerances, I mean a 0.01 mm difference can make considerable variation in all parameters.

Wonder how succesful are the overhauls in all.

I feel very curious to learn more from experience of other members of the forum. awaiting more posts.

Warm regards.
SSaanyal.
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Old 3rd April 2013, 07:34   #42
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Default Re: When it's time to overhaul the engine ?

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Originally Posted by dhanushs View Post
P.S:- Some of the above mentioned issues, like starting and low pick up can also be sorted out by playing with the fuel pump settings. So, I'd probably advice that, before going in for a rebuild.
Mechanics would probably advance the pump timing for quick start from the cold. This may also cause the engine to operate at a higher temperature.
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Old 3rd April 2013, 20:20   #43
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Default Re: When is it time to overhaul the engine ?

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Originally Posted by sanyal779 View Post
Wonder how succesful are the overhauls in all.

I feel very curious to learn more from experience of other members of the forum. awaiting more posts.
Hi,
Agree with some of your observations, disagree with a lot more! Actually most of your observations need (a lot) of qualifiers.

I think half engines come with a crank. Used to be a popular option right from Fiat/ Premier days.

Name one good (not even exceptional) machine shop in Calcutta! (Try this test: Mention, say, torque plate or plateau finish and check the reaction. They will not be able to do it, but do they comprehend what you are saying?)

Regards
Sutripta

Last edited by Sutripta : 3rd April 2013 at 20:27.
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Old 15th April 2013, 23:30   #44
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Default Re: When is it time to overhaul the engine ?

Hi,

Im back writing in this forum to tell you guys that I've got the Bolero XD3P engine overhaul done and Im here to speak about it .

The job took about 15 days to get complete considering the fact that we had a delay in receiving the engine block from the lathe chaps( reboring and stuff) . Overall, a good output . I'm happy about the way the engine responds and feels post the overhaul and am glad that I don't have a cloud of smoke around the vehicle when I halt at a traffic signal anymore.
I have a few questions to ask the experts which I'll hold onto until the end of this write-up. To give a few details :

Bolero GLX XD3P engine overhaul

Duration : 15 days (at the workshop)
Cost: 50 K INR (approx)
Problems prior to the overhaul
1.I had excessive smoke coming out of the Engine breather pipe. More so at idling.
2.Reduced acceleration from low speeds
3.Excessive consumption of engine oil. (I top it up for about 1L for every 1000km)
4.I had to heat up the glow plugs for about 3 times prior to cranking the engine on a cold start.
5.Reduced Fuel efficiency. About 8KMPL in city.

Glad to say that the engine overhaul has solved these issues .

Parts changed :
1.Clutch cover assembly and clutch plates
2.Engine Sleeve
3.Piston
4.Main bearing
5.Con.rod bearing
6.Thrust washer
7.Con.rod bush
8.Piston rings
9.Gasket (All) Kit
10.Head Gasket
11.Valve seats (1set)
12.Valve stem oil seal
13.Engine valve
14.Valve guide
15.M.B.Oil seal
16.Engine mounting
17.Fan belt
19.Belts
20 T.case oil seal
21. Engine oil, coolant etc.,
22. All lathe work
23. Fuel pump calibration
24.All 4 fuel nozzles change

** Theres a high possibility that I could have missed a few parts as Im writing this from memory.

I would like to mention that I got this job done by an experienced mechanic based at Miller's Road, Bangalore.The gentleman's name is Srinivas Naidu. I thought he was very reasonable in the way he listens to the customer to the way he executes the assignment he has taken up.

Now, post the engine overhaul.... I've been driving the Bolero around as much as possible as instructed. I would have to maintain a uniform speed and driving technique not to stress the engine as much as possible for about 2k-3k km on the odo.

In conclusion, I would like to ask the experts/gurus as to how this period has to be handled in terms of driving and maintenance.
And, I have noticed a certain problem to which my mechanic tells me that it would go away as the engine would be used further. The problem is that, the engine does not start on cranking immediately after u have turned off the ignition after a long drive (consider the engine to be heated and stuff). But, once cooled (given a break of bout 15 mins) the engine just cranks in one turn of the key . How're the experts to explain this >?
Will this problem of the engine not firing up go away with time ? as the engine is used/ completed the running-in period ?

Im quite satisfied with the outcome of the engine overhaul on the XD3P and now Im just waiting for the initial 3k km to be over n done with such that I can experience the thorough potential of the vehicle.

Regards,
Sai
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Old 25th June 2013, 09:33   #45
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Default Re: When is it time to overhaul the engine ?

Hi there !

Im back once again and now the Bolero has done about 3000 kms post the engine overhaul and it performs jusssst fine.

But, I have an issue and it is kind of annoying . The engine fails to start after a long drive (considering it gets heated) and will start after about 5 minutes .

My mechanic keeps saying that this will be solved after the engine has been run a little more.I think it can be solved prior to that and it has something to do with the electricals.

Kindly request the experts to revert with their thoughts on this issue. I hope someone else with a Bolero must have faced this issue and has found the solution .

I googled this issue and internationally car owners have this issue . Everyone has a different view on what could be worng varying from starter motors to coolant sensors.

It would be of great help if a Mahindra expert could help me on this front.

Thanks !

Sai
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