blazej01

<center><img src="http://i10.photobucket.com/albums/a130/AudiS4kid/S8Sale/IMG_2777.jpg"></center><p>...with head gasket replaced at 57k miles and t-stat replaced at about the same time? I am talking about 2002 S8

PaulW

So it overheated? Why were they replaced?

blazej01

told me that he saw blue smoke coming from exhaust pipe. Could it be overheating?

PaulW

I would probably just skip if you don't feel comfortable, a lot of them out there

blazej01

i will check the car out and see, at least he wasn't hiding anything from me

Jkay

... for no reason at all. Something in the valve train design.

PaulW

It is ALWAYS when I start the car when cold (and ambient temps 50F or below), move it 20 feet and turn it off immediately. Then you come back an hour later and start it....blue smoke.

Happened on my 97 A8 a few times, and just last weekend on my S8 when I moved it just a few feet and shut it down. When I started it an hour or two later, I was wondering what I saw in my mirror....but it's just unburnt fuel in the engine.

tehA8PIMP

Same here- I presume it is valve stem seals

greenbird

gas would be grey/black.

If it was the piston rings, you would see it most on hard acceleration. If it was valve seals, you would see it on acceleration from idle and startup.

I would have to guess it's from the PCV system, I've seen a good bit of oil in intakes just in the couple months I've been here, and can tell you from past experience that the only way that happens is via the PCV. Some people here have called them breather hoses, they go from the valve covers to the intake tract. The solution is to install special oil/air separator filters.

Also, if you still have cat converters and you can see the smoke, your converters are likely close to death, clogged with burnt oil residue.

audikillsbmw

BTW..How did it blow a head gasket at 57k, if the cars current mileage is 55,951?