My new-to-me B5 has an oil leak somewhere. When I am driving and come to a stop, the smell is evident. But nothing while driving, even slowly. There is no oil on the garage floor, though. Do these symptoms point to any particular issue?

 

Yes; cam chain tensioner seals. Here is a resource you can use to do a little more research on the issue: Audi S4 Oil Leak - Audi S4 Oil Leaks - Audi S4 Oil Burning Smell

 

Valve cover gaskets , cam plugs , timing chain tensioner gasket & seal. One or more are probably causing your problem.

 

Scary, thanks.

 

you said NO oil on the garage floor?


...try checking the cabin air filter and see if it needs replacing... access from under hood on firewall, passenger side...take off cowl plastic

 

I have the same problem. Is there anyway I can check to see if it is one of these things and how would I be able to tell which one it is?

 

Take the plastic engine covers off and take a good look at the valve cover front a rear. Grab a small mirror and see if you can look behind the motor and where the cct is to see where the leak is coming from. If you can't see grab a rag and clean the surfaces and then you will be able to tell where the oil is coming from. Most likely from your valve cover or cct gasket.

 

As I've found out the hard way, even if the gaskets are reasonably okay, if the breather system isn't tip-top, then oil can be forced out past otherwise sound gaskets. That said, I assume the breather system for a blown S4 engine is rather different that the one found on normally aspirated engines. Yes, no?

 

Here are some details for a 2.8 A6 that may be helpful:

cam seal replacement tips?