In keeping with that old adage about raining and pouring, my 2004 S4 has decided to bring me a couple of early easter gifts. Wondering if i could get some input on these before I head off to the shop in complete ignorance:

First up, I noticed yesterday a few spots of oil on the garage floor underneath where the front end of the car sits every night. I lifted it up with a trolley jack this evening and sure enough, there is a nice oily patch on the underside of the splash cover (plastic tray under the engine, if splash cover is not what it's called). It looks like the drips are coming from the square hole in the cover, pretty much central under the engine. The car had an oil change a month ago at the local german car specialist shop I use, and i noticed the oil level after that was slightly over the max. Oil shows just about one mm onto the upper plastic clip on the dipstick, slightly over the max then. Since I didnt have time to make another visit at the shop, I convinced myself it wasnt a big deal..... anyway, Google tells me that an overfill can indeed cause an oil leak, but does anyone have any experience of where the leak may be coming from? Any chance it will go away once the level is corrected?

Second issue... last May i had the front pads and discs replaced due to a bad vibration braking at highway speeds. It fixed the problem. Now the problem is back. This wasn't a gradual thing, last week it just started happening out of nowhere. I'm having trouble believing this could be due to build up on a disc (again) - anyone have experience of brake vibrations on their S4? I've read that a stuck piston might cause vibrations. Winter would seem the right time for stuff to get seized up.

Thanks for any input you may have.

 

Warped rotors might be the cause of your brake issue.

 

Thanks Rod, they're going to check the runout on the disks next time the car's in.

Good news on the oil leak - apparently the source was the drain plug, so hopefully fixed now.