I posted this in the wrong area before.

Hi,

Just bought an A4 B5 about 3 weeks ago. Took it in for it's 90K service last week, but after I pick it up, the Oil Warning light came on on the drive home. I checked the oil level and it was fine.

Next day, no problem, until I was heading home again.

Next day, no problem.

I've noticed that the warning only comes on when driving in traffic or if the Revs falls to below 1000 (about 750), and it's hot (the oil temp reads about 100).

The service guys can't see the problem (I get there early in the morning, with little traffic, so the engine doesn't get very hot).

Any suggestions?