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[Bojan]

Hi guys.

I have a problem that's bugging me for over a year now: from time to time (sometimes after a longer or harder drive, but not always) my car starts billowing white blue smoke from exhaust, sometimes in rather large quantities (I stop at a junction, and a cloud of smoke 'overtakes' me).

The car is '96 Omega 3.0 V6, with 130.000 miles on clock. Last 40.000 miles it runs on LPG. It starts and runs just fine, haven't notice any lack of power on increase of fuel consumption, or any dramatic increase of oil consumption. 

I decided to get this sorted, but would try to pin-down the problem myself.
My first idea was valve ring gaskets (those small rubber rings that go on the valves), but am open to other suggestions (ERG, piston rings  ).

Thanks,
Bojan

PS. also noticed that driver side (UK driver side) exhaust pipe has a lot of black residue on it (like a diesel), while passenger side exhaust side is quite clean. 

[freecall666]

how do you park mig, are you on a incline? if on incline with back end of mig facing up the incline, try the other way round at parking and see if it stops, over night the condensation in air fills up in the exhaust and if it a really damp night can put a lot of water in the exhaust and take a long time for it to be heated up and go out the exhaust as steam and exhaust smoke changing the colour to a white/blue smoke.
p.s black stuff coming off exhaust is the water and soot coming out of a pin hole in pipe or joint.

[Bojan]

well, it's sometimes parked on a very slight incline (in front of my office). But usually on a leveled ground.
And it's quite hot here nowdays.

I've gone trough similar threads here, and saw that it might be connected with blocked breathers. I will check them tomorrow.
However, could somebody explain me how blocked breathers alone could cause something like this?

Thanks!

[tunnie]

how do you park mig, are you on a incline? if on incline with back end of mig facing up the incline,

I'm really struggling to see how on earth that could be of relevance 

Are you actually using any coolant?

V6's do smoke a lot, so unless you are using any fluids, oil/coolant I would not be too worried 

[Kevin Wood]

well, it's sometimes parked on a very slight incline (in front of my office). But usually on a leveled ground.
And it's quite hot here nowdays.

I've gone trough similar threads here, and saw that it might be connected with blocked breathers. I will check them tomorrow.
However, could somebody explain me how blocked breathers alone could cause something like this?

Thanks!

Can't see an incline making any difference whatsoever.

Is it losing oil, and is it certainly smoke rather than steam?

It would be worth thoroughly cleaning out the breather system for a start. Blocked breathers could cause the crankcase to pressurise, forcing oil past the valve stem seals or even piston rings.

See how much oil is present where the breathers emerge while you're at it (just in front of the throttles, and under the plastic plenum cover). Excess blowby from a worn engine could force oil through the breathers resulting in it being burnt.

If the breathers are particularly dirty a couple of quick oil changes until the oil remains clear might be a good step to take.

Is it certainly coming from the exhaust tailpipe? I could imagine leakage from cam covers might drip onto the exhaust manifolds and cause smoke that's noticeable from the front of the car when stopping.

It shouldn't really be worn at 130k so I would suspect breathers and/or cam cover gaskets.

[Bojan]

It is losing some oil (around 1l every 5000km), but it's leaking from crankshaft seal, so I really can't say how much is being burnt.

It's definitely coming out of the exhaust.
Rocker cover gaskets have been replaced 20.000 km ago, and there is no oil there.

There is some quantity of oil residue in front of the throttle, but nothing much. Besides, I've tried puling out the dipstick (engine warmed up) and there was no smoke coming out of the crank (nor when idling or reving).

[cem_devecioglu]

Bojan, I dont say its head gasket problem but the age of the car is older than mine and imo, time is also important factor in head gasket life.. mine was leaking..  

[Bojan]

Cem, do you mean it was leaking between cylinder and water ways?

Anyways, I drove it a bit harder today, to see if it will smoke, but it didn't. After a this harder drive (in town, so lot's of stops and idling) I've pulled out the dipstick, to see if the smoke is coming out (this would indicate excessive blow-by and worn rings) -> it didn't smoke on idle nor while throttled. Only when you press the throttle, it puffs out a bit of a smoke out of the dip-stick tube.
Should I be worried about this?
Both water and oil were quite hot at this time.

Thanks!

[dazzerM]

how do you park mig, are you on a incline? if on incline with back end of mig facing up the incline,

I'm really struggling to see how on earth that could be of relevance 

Are you actually using any coolant?

V6's do smoke a lot, so unless you are using any fluids, oil/coolant I would not be too worried 

X2 I ve had 3 V6 and they do smoke alot I too wouldnt be worried   

[dbug]

how do you park mig, are you on a incline? if on incline with back end of mig facing up the incline, try the other way round at parking and see if it stops, over night the condensation in air fills up in the exhaust and if it a really damp night can put a lot of water in the exhaust and take a long time for it to be heated up and go out the exhaust as steam and exhaust smoke changing the colour to a white/blue smoke.
p.s black stuff coming off exhaust is the water and soot coming out of a pin hole in pipe or joint.

Op disregard all above - Rustyism 

[Bojan]

Quick update on this:

generally, there is no smoke from exhaust. But, from time to time, it starts smoking alot, and it starts all of the sudent.

Also, I wipped the trottle clean few days ago, and done ab it harder 150km since. Checke it just now -> the place where the breather joints into the trottle, there is absolutely NO oil traces. It's perfectly clean. So, blocket breather?

Thanks.

[Bojan]

New update (no good news, sadly  )

I cleaned the breather system, but it didn't make any improvement, as I test drove the car after that, and it started smoking really badly.
Again, it was as usual -> it doesn't smoke at all for some time, and than, in a matter of minute, it starts smoking a lot.

Talked to a mechanic, he said that there is a possibility that ERG valve is not working properly.

Any advice on further action?
I could try blanking off the ERG. If it doesn't help, I'm afraid that the heads will have to come off.

[tigers_gonads]

Blank off the egr valve first then see what happens 

[Johnny English]

I wish you the EGR issue neighbour but don't forget Cem's view either and check the oil and coolant level! If you have no loss no worry then...

[Bojan]

Update on the smokey problem: after ditching the ERG valve, the following is noticeable:
-the exhaust rattle, for which I was sure it was an exhaust manifold gasket, is significantly quieter, and it seems to be coming from a different place
- there is no smoke for now (2 days)
- car seems to be more throttle responsive (when hot)

I've removed the ERG valve and iron cast ducting, blocked off the holes on the intake plenum, and blocked off the copper pipe coming from the exhaust manifold. ERG valve is plugged in and placed aside for now.
I will be try to unbolt the copper pipe on the exhaust manifold connection fitting, and placing an end cap fitting there.