[johnruben]

Hi Bhp'ians,

I am having a very strange overheating issue with my M800, Please help me to fix this issue.

Car details:

Year of Mfg: 2001
Variant: STD (w.o A/C) MPFI
condition: Mint
Mileage: 45.5k KM

Couple of weeks back, I went through bumber-to-bumber traffic (~30km) with full load and when i was about to park the car, Radiator fan started and i was waiting for it to auto cut-off, usually it shuts down in a minute or two, but it was not turning off even after 5mins and when i looked at temperature gauge it started moving above normal and i was shocked, I immediately switched off the engine. I let the car cool down and i returned home with no load and reached without any traffic, just when i was about to park my car, same thing happened, fan started to run at idle and temperature gauge started to move upwards.


I PM'd SirAlec and PavaKadam and they both told me to check Radiator cap and Fan, so next day i took to bimal, changed Radiator cap, he checked if fan is cutting-off in 1 min and it was normal, he couldnt find any issues. one thing i have noticed when this happens is, coolant in the reservoir becomes full till the lid (more than max, when engine is hot), and sometimes when engine is warm, coolant is near min, seeing its in min, when i add coolant b/w min and max and check after a while, it goes above max, full till the lid.
Coolant behaves strange and temperature Gauge goes above normal and radiator fan keeps running and running.

Last service was 4k KM back and Radiator was not flushed, but coolant was removed and added back again (mechanic confirmed coolant and radiator is fine).

few days back i saw white smoke and today also white smoke came for few mins, both times it was raining and weather was cold. I am not getting continuous white smoke, is this normal ?

final conclusion by mechanic in bimal is to check thermostat, radiator switch and atlast to remove head gasket and check, for now, if i drive within 25km, fan does auto cut-off and everything is fine, except coolant position behaving ackward, so please tell me if someone has come across an issue like this and what are the things i need to do in minimal cost to rectify this problem.

PS: Mods I didnt find a thread exactly same as this and i am desperately trying to find a solution, Mods I Request you to please let this post remain here and not be moved.

Thanks
John

[ghpk]

it can be some clogged pipe in radiator itself as you said reservoir gets full.

There may be some debris kinda stuff from a 9 yr old radiator and it may be preventing full circulation of the coolant and then filling up the reservoir, better to get radiator checked before the over-heating damages anything on engine.

[dragger]

Check thermostat switch,pinch in water pipes,if the car has an ect (engine coolant temperature sensor) on the elbow check if that is working properly,fan fuse/relay,do a compression check,also remove the dipstick and check if your oil looks milky white,then its a head gasket failure,just try these various options,you should get a satisfactory answer by the end of this troubleshooting,hope this helps,cheers,happy revving..!

[Hashim]

You are about to have head gasket failure, get the head gasket replaced. It can happen anytime so its better to get it done before it fails than getting struck somewhere on road.

[luky_13]

Some possible causes could be...
1. Blockage in the coolant plumbing
2. Leak in the coolant lines
3. Water pump failure.

and also as stated, the head gasket failure which leads to excess smoke.

[johnruben]

Thanks Guys for all your replies,

@dragger, Service guys in bimal does not know compression test :(
Oil level looks absolutely fine and there is no milky white in the oil. Service guys checked water pump working fine, no squeaking sound and when engine warmed, coolant comes up in the radiator (radiator cap opened) showing water pump functioning.

@lucky_13, there is not visible coolant leaks anywhere in the engine room and water pump is running fine, however i am not sure any blockage in the radiator.

so, based on all your reviews i have made a small list of things to check, please tell me if its correct:
1. Coolant / Radiator Flush
2. Thermostat replacement
3. Radiator switch / relay replacement

@Hashim, how sure you are about head gasket? because Bimal said cost of the gasket is around Rs. 50-100, but labour is Rs. ~1300.
Please advise if i should change the above 3 parts or get head gasket replaced alone. b/w oil looks fine that means head gasket is fine right ?

[bhp_maniac]

Originally Posted by johnruben

Thanks Guys for all your replies,

@dragger, Service guys in bimal does not know compression test :(
Oil level looks absolutely fine and there is no milky white in the oil. Service guys checked water pump working fine, no squeaking sound and when engine warmed, coolant comes up in the radiator (radiator cap opened) showing water pump functioning.

@lucky_13, there is not visible coolant leaks anywhere in the engine room and water pump is running fine, however i am not sure any blockage in the radiator.

so, based on all your reviews i have made a small list of things to check, please tell me if its correct:
1. Coolant / Radiator Flush
2. Thermostat replacement
3. Radiator switch / relay replacement

@Hashim, how sure you are about head gasket? because Bimal said cost of the gasket is around Rs. 50-100, but labour is Rs. ~1300.
Please advise if i should change the above 3 parts or get head gasket replaced alone. b/w oil looks fine that means head gasket is fine right ?

First suggest to check for radiator clogging in any case. If coolant is running without any issues, then it may be probably a head gasket issue. Radiator switch may not be the culprit since the fan is working fine and well. For me, it smells like a head gasket failure.

[gavinimurthy]

I faced a similar problem on my Maruti 800, 1996 make, a few months ago. I replaced the radiator and head gasket and problem solved.

The radiator gets clogged over a period of time and if it happens the only solution is to replace it. Once you face the overheating problem, there is always the likely hood of the head gasket getting damaged. Better to replace it as a precaution.

Murthy

[gavinimurthy]

This information may give some clues.

Overheating: Symptoms and causes

Murthy

[johnruben]

Thanks Murthy and bhp_maniac for your valuable inputs.

murthy after reading the link you gave me, i have decided not to run the car unless i fix it. I will change full radiator to new one and also replace head gasket, i will also change engine timing belt.

Will post here once i fix all issues. Thank you all.

[Jaggu]

Before you do any of the ^^^ do check the thermostat, the temp sensor and rule out any issues with them.

[johnruben]

Update:

Bimal was full and i was not getting appointment, I took it to a local mechanic.
He checked the car and told its a Thermostat Valve failure not allowing enough coolant inside and he removed it, he then made some coolant to overflow from reservoir.

He, then asked me to bring 1ltr Castrol Coolant and Distilled Water, then he added it to Radiator, Now Fan was not running like before, it will auto cut-off in a min in idle and temperature is not going above normal, but coolant is getting above max in reservoir.
I feel if i drive for 2hrs (which i have not still), then temp guage might rise as this was what happened last time.

I have also noticed few bubbles in reservoir after some acceleration, then it dissapears.

Now vehicle is without thermostat and coolant accumulating at reservoir. Is it ok to drive without this thermostat valve and can anyone recommend me a good garage in bangalore ?


Thanks

[Jaggu]

Nothing wrong in running without thermostat, only issue will be it will take lil longer for engine to heat up to ideal temperature during first start. Moreover you can fit a new thermostat if it is the culprit.

Did he check if the water pump is working properly? Its normal for coolant to rise a lil bit, that is why they have some more space left after max level. But it shouldnt overflow if the engine is not overheating.

[johnruben]

Thanks Jaggu,

Got your PM about suraksha, will call them tomorrow and ask for appointment.

As and when i am driving, Coolant level in the reservoir is increasing, it goes above max and till the lid, i have been driving this car very long and it had never happened. couple of months back there was a leak in Hose and coolant used to go low on level but never it has increased in the reservoir. I guess i have to get this head gasket replaced asap.

Ya, I will also ask them to fit new thermostat as it was not the culprit, then will change head gasket + Radiator replacement/Flush.

[johnruben]

First of all thank you everyone for your replies and suggestions,

You guys were absolutely right, I returned from bimal in the evening with a fix on my car, sorry Jaggu couldnt go till suraksha. The culprit was Clogged internal Radiator and minor damages to Head Gasket. Head Gasket was replaced, Radiator was overhauled, also timings were adjusted and i asked them to replace timing belt and bearing since they had opened up the engine and finally a new thermostat valve which my local mechanic removed was added.

When i reached there, they were filling my old engine oil + did a top-up, they freshly added golder cruiser Coolant (blue) since old was flushed and when all done we went for a test drive, temp needle was absolutely in center and no overflowing of coolant in reservoir, mechs confirmed, engine is absolutely fine and will zoom for another 1lac+ KM.
Final bill came to 3.6k and now i have a peace of mind.

Tomorrow will be driving car in bangalore traffic and hope everything is fixed and no issue arises. Thanks you all once again for helping me to figure out the issue and solve it.

Thank you TEAM-BHP.