smoke from exhaust? - BMW Forum

w1nm · 08-19-2011, 04:03 AM

So I just finished installing an aa track pipe, I've never had issues with smoke from the exhaust but now every now and then when I decelerate to a stop it will spit out a decent amount of grey/white smoke. What's the deal?

brettski · 08-19-2011, 09:17 AM

Is the smoke present as you stop or when you take off after stopping?

w1nm · 08-19-2011, 10:08 AM

so here is what I've gathered,

no smoke present upon cold start
after it warmed up to operating temperature i shut it off and let it sit for about 10 mins. Started it back up and there was a split second of smoke, just a quick puff.

It only smokes when I'm coming off the throttle to a stop or slightly when I pull away from a stop. When I'm pulling away though its barely noticeable and neither one is consistent.

Never is the smoke present at regular idle.

This should be noted as well, I opened up my oil cap and there where light white vapors coming out, along with that a very faint smell of gas.

Jack Dabsy · 08-19-2011, 01:24 PM

Listen carefully... Initially, I would suspect the head gasket, however... Yours seems intermittant !
Is it definately grey-white or is it grey-light blue?
Grey-white would suggest coolant in the cylinder(s)...
Grey-blue may suggest valve stem-seal(s)...

Usually, a failed gasket will track from a cylinder to either an oilway or coolantway, but it is not impossible for a head gasket to fail across the oil and coolant ! This could cause the coolant to vapourise in the breather-pipes before it re-enters the engine to be burnt once again !!!
This is just a thought my friend and I hope this helps...

w1nm · 08-25-2011, 04:17 PM

Thanks for the replies,

Still smoking every now and then upon stopping. Like I said no smoke at start up at idle. Think it could be worn valve stem seals or guides? It's about time to change out my spark plugs, I'll be doing a compression test along with them. Oh and the smoke color is blue, so it has to be oil that's getting in some how.

rampage601 · 09-14-2011, 08:10 AM

could be pistons and rings something to do with the oil getting where it shouldnt be is what ive always went by..white/grey= oil black= i cant remember right now its too early sorry haha when i remember ill let you know..smoke colors actually really help

Jack Dabsy · 09-14-2011, 02:17 PM

LOL White/Grey = Coolant burnt in cylinders !!
Light blue = Oil Burnt in cylinders...
Black = lack of air or very rich mixture.
Go back to bed for another hour... Hehehehe