More smoke!

[Timo]

I have now determined when my car smokes and I haven't a clue why. Today I had to wait for someone for over an hour. I sat in the car, with the engine turning over, just to keep the car warm and the battery charged as I had the radio on. There was no smoke o the way there, and no smoke when idling. When I went to drive away, there were clouds of white smoke coming from the exhaust. I feared someone would call the police or the fire brigade! This got worse each time i went to pull away. After driving for for a few miles, the smoke stopped, and after 30 miles o the motorway, has disappeared completely.There was no noises, no alarms no difference in the car, just clouds. I noticed this before when i had sat idling for a period of time, but never linked it for certain. I have already had a head gasket water pump and turbo in the last 8 months. Please tell me I don't have to dig out more cash.

[cheezemonkhai]

You sure it is white and not slightly blue.

I'm thinking maybe the oil in your engine is too thin, such that as the car warms up the oil thickens and so can't get past the rings as the really thin stuff is doing. Not sure that is the case though. What oil do you use is it a 0w-something?

What is your engine again (sorry I forget)

Also do you only get white smoke when the engine is cold, as if so it could well be worth draining the fuel filter. I guess it might be worth putting a bottle of the stuff in the fuel tank that gets rid of water from your fuel tank before you change or drain your fuel filter.

HTH

[Timo]

Its a vrs. This is when the engine is warm. If I sit with the engine ticking over on idle for 20 mins or so, and it smokes like a mo fo when I increase the revs to drive off. Not normal slow traffic or anything, If drive normally, then there is no problem. I am using castrol gtx magnatec 10w40, it was the spec that halfords recommended for the car.

[cheezemonkhai]

Is that a fixed service interval?

I can't see gtx magnatec being good enough for that engine myself, does it meet the VW specs?

So if you idle for a long period then you get smoke, but not when driving normally. Idling will cause things like this to a point, most old cars (not seen new petrol ones) say don't idle the car for long periods of time.

If only when idling i would think maybe you are just building up water, so i would do what i suggested above to get rid of as much as you can from the fuel.

Personally I didn't rate GTX magnatec highly, and used to use millers XSS semi instead. If i were you I would get a decent 10w-40 fully synthetic for the engine.
Millers do one, and Mobil 1 apparently is good for the job too if you are on fixed.

[martziniuk]

I know its probally not related but we had a tractor with a blown turbo.It was fine when idleing but when revs increased loads of white smoke came out and it used alot of water.

[KenONeill]

What's the oil consumption like:-
1) Typically, during a non-smoking period?
2) Measured just after a smoking period?

I know this may take a while to answer, but I've got a vague idea, along the same sort of idea as martziniuk I think.

[Kandy]

Talking with vauxhall C20LET experience here, but probably still applies.

It's not generally a good idea to let turbo engines idle for a LONG time as the turbo bearings are designed to operate under high oil pressure/load/temperature.
The bearings are designed to pass a small amount of oil which will find its way into the intercooler/pipework etc. and will be burnt off immediately in normal driving.

I suppose it's possible this oil is building up 'pooling' even whilst you are sitting idling and may take a while to get sucked through and burnt - may be normal for this car/turbo or may indicate a worn turbo.

[cheezemonkhai]

Well if you let the engine idle for too long you could have built up oil as Kandy said when blue, but also you will get water build up in the exhaust as the pressure on the exhaust isn't sufficient to blow it past the cat etc. The CAT does generate water from the combustion products.

If it only ever happens after a long idle, then I would say it is because you are idling too long. I'd still use a better oil mind.

[Timo]

Having just had a new turbo put on, I will be f'ing and blindin' until the cows come home if it is. This happened before it was replaced, and was one of the reasons I got the garage to check the engine over, resulting in the new turbo, as they discovered a heavy oil leak from it. Due a service in the next 1000 miles. will take it to a different VAG specialist garage and get them to have a look for me.

[helmutderhaas]

Could be the injectors ?

Maybe the MAF, I tried starting mine one morning with the MAF disconnected , was like a smoke screen ...

Generally that much smoke is from a bad fuel/air mix.

[cheezemonkhai]

Seriously, exhaust gases have water in them, and a catalytic converter creates large amounts of water, this is why you often see water running out of the exhaust of a cold car.

If you have the car warm and idling for very long times the cat will build up a load of water in it, and as such when you go to drive off this is going to get flushed out by the higher exhaust gas pressure.

If you are not loosing oil and not loosing coolant then I really don't see where the water (white smoke) can be coming from apart from the cat oxidising the CO to CO2.

For piece of mind get one of them granville head gasket leak test things where you test the coolant water, but I think you are looking for a problem that isn't there.

[Lummox]

Originally Posted by cheezemonkhai

Seriously, exhaust gases have water in them, and a catalytic converter creates large amounts of water, this is why you often see water running out of the exhaust of a cold car.

If you have the car warm and idling for very long times the cat will build up a load of water in it, and as such when you go to drive off this is going to get flushed out by the higher exhaust gas pressure.

If you are not loosing oil and not loosing coolant then I really don't see where the water (white smoke) can be coming from apart from the cat oxidising the CO to CO2.
there.

Exactly spot on very correct A+ go to top of class that man.

Water burns off and makes steam aka white smoke.

[rhys57]

Hope its got nothing to do with the remap mate.

[Timo]

No, the car has 110k on it, it was doing it before the remap.

[cheezemonkhai]

As I have said, and Lummox agreed, if you idle a car for that long you are going to build up water. It is to be expected.

[Timo]

Thanks, wallet was poised at the ready with the boot into the side of the car to follow. can breath easier now.

[cheezemonkhai]

Originally Posted by Timo

Thanks, wallet was poised at the ready with the boot into the side of the car to follow. can breath easier now.

Glad to hear it.

I would stop idling for that long mind as the low oil pressures can't be good for the various bearings in the engine.

[KenONeill]

You think the pressure in the galleries is the same as that in the bearings!? Most mechanical engineers now accept that the hydrostatic pressures in the bearings are thousands of PSI, rather than the 15 to 45 PSI that the galleries run at.

[cheezemonkhai]

Dunno mate, but I'd rather not chance it.

At the same time i wouldn't use GTX magnatec so maybe it's a personal thing.

[KenONeill]

I'm not suggesting that it's good practice; just that your reasoning is wrong if it's based on gallery oil pressure.

I wouldn't use Magnatec either, but maybe that's cos I had a nearly all alumium mengine when it first came out, and assured me that it would "stick magnetically to the engine. I figured that, when the only bits it could stick magnetically to were the crank, camshaft, valves, rods (but not big ends), and gudgeon pins, it had a poor chance of doing any good over a filter with a non-return valve.

[Kandy]

Back to the OP's issue - to me, the problem sounds far more than normal water vapour in the first paragraph.

Several possibilities spring to mind, especially given the engine's mileage, still, if coolant/oil/performance/emissions are all reasonable and no trouble codes, not a lot of point worrying unless you get pulled over for it is there!

Next time it's doing it badly you might pull over and see how it smells - oily, sweet, car fumey!

The turbo replacement definitely cured your oil leak did it?

[cheezemonkhai]

Kandy...

It only does it if he has been sat idling for a long period eg 20 mins and not any other time. He isn't loosing oil or coolant. The car doesn't smoke when he drives normally.

It is white smoke, which means water not oil.

I don't see why there has to be any other explanation. Combustion of hydrocarbons creates water.

C8H18 + O2 ---> 8(CO2) + 9(H2O)


That assumes perfect combustion of octane (the ideal petrol) in pure oxygen, which doesn't happen, hence you get some unburned hydrocarbons, Carbon Monoxide and NOx out of the exhaust.

So you see you are getting a sh*t load of water produced that has to go somewhere. Now with a cat in the way and low exhaust pressures (eg when idling) there is no way that the water will all come out of the exhaust. Some of it will pool up in the cat and other parts of the exhaust system.

When the car pulls away, this is pushed out by hot gasses (above 100*C) and that in combination with the water hitting hot surfaces produces a large cloud of white "smoke". White smoke also commonly known as steam.

EDIT damn the editor for not having subscript. I will have to do molecular disassociation models manually as an image

[Kandy]

FWIW the fact that it does it after a period of idling could indicate an oil leak/seepage, internal or external amongst other things. Oil smoke is often almost white with just a slight blue tinge and a few drops go a long way.
I'm not disagreeing with the water theory - but the intitial description clearly indicates that it is to an abnormal extent and it is impossible to give such a definitive diagnosis remotely.
Further, in another post the OP has indicated previous oil leak problems, believed to be related to the turbo.

[DGW]

I seem to be quoting from the Owner's Manuals quite a lot recently in reply to posts, but there is information there which can fade from memory over time. In this particular case the Manual says:

Do not allow the engine to idle for a lengthy period. If the engine is running when the car is stationary, there is not always an adequate flow of air through the radiator. In certain circumstances, this can result in the engine overheating and also in engine damage.

[cheezemonkhai]

Originally Posted by Kandy

FWIW the fact that it does it after a period of idling could indicate an oil leak/seepage, internal or external amongst other things. Oil smoke is often almost white with just a slight blue tinge and a few drops go a long way.
I'm not disagreeing with the water theory - but the initial description clearly indicates that it is to an abnormal extent and it is impossible to give such a definitive diagnosis remotely.
Further, in another post the OP has indicated previous oil leak problems, believed to be related to the turbo.

When was it normal to idle for 20 minutes?

He isn't using up oil and he isn't loosing coolant so where else does white smoke come from... exhaust gases. No that isn't a 100% cert, but it's a pretty good diagnosis.

A small amount of oil in the turbo isn't abnormal at all, especially with cars with EGR systems, and bearing in mind he has already had a load of work done which has not solved this issue, it makes sense to stop the long idles and see if the problem comes back rather than throwing more money at it.