[V6-12v] 2.8 12v burning oil?

[George Tur]

On Friday 06 October 2006 05:35, James Whitehouse wrote:
> I haven't experienced that, but in my experience valve stem seals normally
> show themselves when you notice smoke in your mirror off, not on, the
> throttle, e.g. as you go downhill. That's not to say they couldn't smoke on
> acceleration I guess but I think it's more likely to be something else.
>
You can get smoke on acceleration if it's in a lot of stop and go traffic. The 
repeated higher intake manifold vacuum will pull oil down the intake guides. 
Granted this will usually burn the oil off but if the guides and seals are 
really worn you'll see smoke on acceleration.

If the rings or cylinder walls are worn then you won't see smoke on startup 
but you will see smoke while running.

The only reason I know this is because I'm going through this scenario with my 
Audi V8. It's been burning oil on startup and acceleration and the local Audi 
guy has looked at it and swears it's the valve stems and guides. According to 
him it's classic symptoms. 

For the V8 the cost of the head rebuild is about $1000 while for the 5 
cylinder Audi engines it's about $600. I guess a 6 cylinder head rebuild will 
be somewhere in between. 

The mechanic also said that in some cases they can do the valve guide 
replacement while the head stays on but in those cases they won't warranty 
the work because they can't vouch for the condition of the valves, seats and 
the head itself. 

Some of the stuff you pick up when running an Audi with over 200k miles on it.

George 
with the smoking V8