pug 205 1.6 gti (F reg) + smoky exhaust

I am experiencing a smoky exhaust. The smoke isn't blue or black just
greyish.

Any idea what causes the smoky exhaust and how I can rectify the
problem. The car runs and idles well.

Thanks

 

Have you checked the water level? Steam-coloured exhaust can signify a head
gasket on the way out.

Ron Robinson

 

Water level is 'A OK'

Exhaust smells a bit oily

Sp.

 

If smoke is all the time, or under acceleration, it's an indication of worn
piston rings.

If on start up, or backing off the throttle, it's likely to be valve seals.

 

I don't think that either really apply

Its not really noticable when driving.
But when at the lights, or in a traffic jam, or just idling, then its
notceable

Thanks

Sp.

 

Black smoke is burning too much fuel, the 205 does have some hesitaton
problems at idle, A lot of people chip them to sort this issue.
It could well be overfuelling, I suspect a quik emmisions test would
tell you that though, as emmisions would be up a fair bit.

It doesn't sound like any oil is being burned as this would usually
create a blue haze from the exhaust.

It could be steam vapour, especially if you have an aftermaket boy racer
exhaust fitted as these can hold a lot of water inside them, especially
if you never do high mileage too warm them up and you wash it regularly
or use car washes.

Don't dimiss impending head gasket failure though, it would only take a
very very small leak into the cylinders to create a steam trail, it
would not even have to leak enough water to effect the water level.

Andy

 

Thanks for responding

What about the problem only occuring at idle

What did you mean by 'chip them'

Thanks

sp.

 

The GTI's - I don't know if it's only the 1.9 or both engines suffer
from hesitation at low revs and idle badly.
The fix for this is to have them chipped, i.e. have the ECU reprogrammed.

If a car is only smoking at idle that is usually just because it is more
noticable as the exhaust gases are travelling a lot slower.

If a car had blue smoke at idle it would indicate that oil was running
down the valve stems past the oil seals and into the combustion chamber.
This is usually caused by hardening of the seals and is common on
engines that tend to run at higher temperatures such as french petrol
engines, however, you state the smoke is not blue.
This small oil leak is not enough however to cause blue smoke at higher
revs so the usual rule is that if the smoke continues to below out even
under load then oil is being pulled past the oil scraper rings on the
pistons on the downward stroke, thus burning oil.
This can only be corrected by replacing the rings and re-honing or
reboring etc... - usually fairly terminal as bearing etc usually need
replacing also after this kind of wear.

Excess fuel, which I suspect is your problem can be caused by several
faults, one of which is blocked fuel injectors, another is a faulty
Lambda sensor, another is a broken/faulty ECU etc....

As I said earlier, the only real way to tell what type of smoke it is
would be a gas emmisions test, post the results and lets have a laugh.
If the Hydrocarbons are way up it would tend to point to too much
fuel/oil. If emmisions are ok, then it's probably water vapour.

I hope I got that correct ??? - And real mechanics out there please feel
free to corrct me, I have nothing against learning new tricks

Has yours got a CAT ???

Andy

 

No CAT

IS ECU another name for the air flow meter? If not, I don' think I've
got an ECU?

Wouldn't too much fuel lead to black smoke?

What about the effect of the breather system on the quality of the
exhaust?

 

Your ECU is inside under the dash board.