dhoerl

My 99 A6 2.8L started leaking oil a few months ago, got to 1Qt every 60 miles. The oils pools in the center of the engine bay, up front, but its splatter everywhere in the engine front. I just pulled the front of the car off - the accessory belt was soaked with oil. When I pulled the crank pulley, and looked at the timing belt, its absolutely clean of oil. There is a bit of oil on the engine behind the crank toothed timing belt pulley, and there was a bit on the back of the black plastic cover that surrounds the crankshaft - but not as much as I would have thought given the leak severity. The cam seal one both sides looks bone dry.

I thought I'd post here before I go and replace the main seal - I just cannot believe I could have a leak of that magnitude and not have a totally soaked timing belt. There is no obvious leak anywhere else, but nothing I've read would point to anything but the main seal.

Anyone else had this?

pr0xZen

Have you checked your vacuum jet pump? Roughly in the middle back, under the top bracket, above the throttle body. If this clogs, it'll allow pressure to build up in the heads, and blow seals, valve cover gaskets etc. If you happen to have an old type oil cap (just solid underneath), that is a failure point too (newer type cap has a built-in pressure release valve). If the spider hose is old stock, that can clog up too - and pressure has no way out other than the top seals and gaskets.

kbunting

I had similar problem on my 2000 A-6 3 weeks ago and it was the front crankshaft seal.
I used 1 quart of oil to go 10 miles locally, a real gusher.
Had seal replaced and now all is dry and no more leaks.
Kurt

jcman

Whatever you do don't run that engine until the seal is replaced, loose the timing and the real nightmare begins.

dhoerl

So I got the timing belt repair kit and tools from BlauParts, and tore the engine apart again (I had replaced the belt two years ago, only 20K miles on it). I pulled the crank pulley off and found just like so many others have that the d*mn seal had popped out!!!

I used a low pressure system (see my Forum Tech Article on the Jet Pump) to verify I did NOT have pressure when driving the car, so the popped seal was NOT due to crankcase pressure (essentially you install a U tube of PVC half filled with water, connect it to dipstick tube, and watch water level rise of fall - to get "inches of H2O" as a pressure/vacuum measurement. Audi has a spec on what is normal - its in my post I recall.

Since I also have had that burning oil smell in the cabin when the windows are closed, I decided to do it right this time, knowing I might destroy the engine as this was a stretch for me.

So, I replaced the crank seal, then removed the belt, then the cam gears (what a PITA that was), then the valve covers. On the driver side I could replace everything with the cam loosened but not pulled, on the passenger side I wasn't comfortable trying to replace the rear gasket with the cam in place, so I pulled the whole cam out and did it right (another PITA - working alone). I read everything I could on this, and watched videos on YouTube.

In the end I replaced every seal and gasket, and cleaned as many of the parts off before putting them back as I could. The engine still appeared to leak for many weeks - but it was old oil dripping off the engine.

Now, after 2K miles and two months, the engine is not leaking a drop of oil. In fact, its running better than every (I believe since I finally did the cam timing correctly, which requires the timing belt to be tensioned first, then the cam gears tightened while help in place with the BlauParts tool.

This was a huge amount of work - I took two weekends to do it - but now my 16 year old car has hopefully a longer life ahead of it.

PS: in the end, the apparently clean timing belt was a red herring. Taking it off, it looked clean - it did not appear oily - but of course it had a thin film of oil on it.