My 19TD has started to give out white smoke. It seems to be only on over run i.e. when the revs are dying off. I noticed it first when the car was cold but it has just done it after a 10 mile run.
Could this be the vacuum operated cold start device causing over fueling? How do I check this and what else could it be? The car has done 145K miles.
Phil
smokin xantia
Moderator: RichardW
White smoke from an engine (wether pet or derv) is either water or evapourated engine oil.
If the engine was overfuelled the smoke would be black.
If the engine oil is soaked into the combustion the smoke would be blue.
Hold a cloth against the exhaust while engine is running. The smell and feeling of the cloth afterwards quickly tells you why it smokes.
The turbo is likely to fail on the hot side oil seal - when it fails - producing white smoke from evapourated engine oil.
If the engine was overfuelled the smoke would be black.
If the engine oil is soaked into the combustion the smoke would be blue.
Hold a cloth against the exhaust while engine is running. The smell and feeling of the cloth afterwards quickly tells you why it smokes.
The turbo is likely to fail on the hot side oil seal - when it fails - producing white smoke from evapourated engine oil.
Anders,
Thanks for your response. Could you say more on the water possibility please - where might the water originate? Could this be a symptom of the head gasket failing where the water was coolant? Or water taken in through the air filter?
It seems to be getting worse, only clearing after about 10 miles when starting from an overnight stop.
Phil
Thanks for your response. Could you say more on the water possibility please - where might the water originate? Could this be a symptom of the head gasket failing where the water was coolant? Or water taken in through the air filter?
It seems to be getting worse, only clearing after about 10 miles when starting from an overnight stop.
Phil
-
- Posts: 89
- Joined: 03 May 2005, 19:06
- Location: United Kingdom
- My Cars:
Old trick- ignore Health & Safety! Wait until you have water DROPLETS in the tailpipe then dip finger in....and Taste. If head gasket is going it will taste of coolant which is quite distinctive and is a good diagnosis. (please dont ask what coolant tastes like.....). A similar SMELL need not be the same thing but simply 'exhaust' fumes from the aircon if fitted: I was told this by a local Cit. repair man but even he hasnt a clue why this appears in the exhaust.
- CitroJim
- A very naughty boy
- Posts: 49662
- Joined: 30 Apr 2005, 23:33
- Location: Paggers
- My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
- x 6208
- Contact:
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Philjw</i>
Phil,
That's an interesting idea. I'll give it a go. I do know what glycol coolants taste like...rather nice really. But as you say not healthy
Thanks,
Phil
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Presumably thats why they put it in wine... [:)]
Phil,
That's an interesting idea. I'll give it a go. I do know what glycol coolants taste like...rather nice really. But as you say not healthy
Thanks,
Phil
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Presumably thats why they put it in wine... [:)]
Remember on the overrun there is NO fuel being injected - so whatever is coming out is not fuel. This also means that there is no combustion to ignite lubricating oil, and I think if the turbo was leaking you would get a cloud on acceleration when the hot gasses burnt the oil that had leaked out while you were on the overrun.
It does sound like water and your mechanic's theory of the head beingporous in the valve area sounds plausible. In fact it leaks all the time but the vapour comes off as steam and is invisible with combustion heat but without that heat it comes out as white vapour.
Of course if it is in this area it isn't under much pressure and a leak stopper could have good results. I accept its not ideal but but nor is buying and fitting another head.
jeremy
It does sound like water and your mechanic's theory of the head beingporous in the valve area sounds plausible. In fact it leaks all the time but the vapour comes off as steam and is invisible with combustion heat but without that heat it comes out as white vapour.
Of course if it is in this area it isn't under much pressure and a leak stopper could have good results. I accept its not ideal but but nor is buying and fitting another head.
jeremy
Kowalski - You are right of course...but are there any Austrian cars?
Jeremy - What bothers me about the leak stopper is the prospect of clogging the heater matrix and cuasing another fault.
I'm now convinced that is is water since the coolant drops by about a litre in a 30 mile drive. The steam / smoke does stop after about 10 miles i.e. when the engine is hot. This gives me another question - is the gap sealed by expansion or is it as you say here that the steam does not condense at this temperature. If it was the first, is there any possibility that re-torquing the head might seal the gap?
Jeremy - What bothers me about the leak stopper is the prospect of clogging the heater matrix and cuasing another fault.
I'm now convinced that is is water since the coolant drops by about a litre in a 30 mile drive. The steam / smoke does stop after about 10 miles i.e. when the engine is hot. This gives me another question - is the gap sealed by expansion or is it as you say here that the steam does not condense at this temperature. If it was the first, is there any possibility that re-torquing the head might seal the gap?
Must be overpressure in the radiator then ?
I would NOT try re-torque the headbolts. Risc is you over-torque the bolts and they snap.
Most likely the cylinder head is warped and then the HG allow for a path between combustion/exhaust and the coolant.
To get rid of the problem it would be the standard procedure : head off, get it checked and machined, new gasket and bolts and you're on the road again.
Some 100-150 quid DIY dependent on parts needed. 2-3 times that in a garage.
Only if you miss your luck you would need a recon (or new) head. It's not a rule.
I would NOT try re-torque the headbolts. Risc is you over-torque the bolts and they snap.
Most likely the cylinder head is warped and then the HG allow for a path between combustion/exhaust and the coolant.
To get rid of the problem it would be the standard procedure : head off, get it checked and machined, new gasket and bolts and you're on the road again.
Some 100-150 quid DIY dependent on parts needed. 2-3 times that in a garage.
Only if you miss your luck you would need a recon (or new) head. It's not a rule.
i wouldn't worry too much about leakstopper blocking things - some manufacturers (including Jaguar) used to use as standard/recommend from new.
The current favorite seems to be Forte. I don't think you will have much trouble with one dose - its repeated applications that will cause problems.
However if Anders is correct and the head gasket has gone then its best dealt with promptly. I'm only suggesting the stopper if the thing has gone porous in the region of the valves.
I must say I've never heard of this problem. The head on my BX TD was found to be cracked and curiously it didn't loose any significant amount of water. I never actually saw where the problem was but apparently its common for the combustion chambers to crack with very small cracks and as soon as the engine runs the alloy expands and closes the cracks. Had the head gasket not failed between 2 bores - no water loss! it would probably have gone unnoticed for some time but it wasn't worth putting that head back on.
To answer your point about the vapour ceasing after 10 miles - I'm surprised - the critical parts of the cylinder head will have reached full temperature after a mile or so and the exhaust will vary in temperature according to load. I don't know if its like a bX with a very large silencer at the back - which could take some time to clear.
jeremy
The current favorite seems to be Forte. I don't think you will have much trouble with one dose - its repeated applications that will cause problems.
However if Anders is correct and the head gasket has gone then its best dealt with promptly. I'm only suggesting the stopper if the thing has gone porous in the region of the valves.
I must say I've never heard of this problem. The head on my BX TD was found to be cracked and curiously it didn't loose any significant amount of water. I never actually saw where the problem was but apparently its common for the combustion chambers to crack with very small cracks and as soon as the engine runs the alloy expands and closes the cracks. Had the head gasket not failed between 2 bores - no water loss! it would probably have gone unnoticed for some time but it wasn't worth putting that head back on.
To answer your point about the vapour ceasing after 10 miles - I'm surprised - the critical parts of the cylinder head will have reached full temperature after a mile or so and the exhaust will vary in temperature according to load. I don't know if its like a bX with a very large silencer at the back - which could take some time to clear.
jeremy