Oil leak issue

[bteamplayer]

Hey all. I'm at 70k miles and just recently noticed an oil leak. My shop was not 100% sure where it was coming from, and as a first step, I am replacing the breather line that there was a TSB out for (https://static.nhtsa.gov/odi/tsbs/20...75308-0001.pdf). If this doesn't solve the issue, does anyone know what it could be based on experience with their cars? The shop said it could be a rear main seal leak, but they are not sure as they have not seen a lot of higher mileage B9 S4s. I have a stage 1 tune, intercooler, and intake.

Thanks.

[CELison]

That can be from a couple places. Impossible to tell without digging in there, but your usual suspects are:

Timing Cover
RMS
Oil Filter Housing gasket. Leaks down the valley and drips at the bell housing. This is easy to diagnose with a flashlight.
Oil cooler. Leaks down in the valley then drips at the bell housing. Another pretty simple one to diagnose.

[wweese]

I’m at 65k and my oil filter housing was replaced under warranty for leaking. They also replaced the PCV breather hose as they said it can be the cause.

I’ve also heard of the PCV itself leaking, but that be simple to check.

[bteamplayer]

Turns out my leak was the oil filter housing! Seems like this is coming up for a decent amount of people these days.

[JD.]

I had to change my oil filter housing at 105,000km. I did the entire housing (gasket and new filter were included) instead of just the gasket. Worked out to about $600CDN in parts. It’s pretty easy to do if you have an 8” extended t30 bit.

[spacecase]

Huh looks exactly like my oil leak. How did they figure it was the oil filter housing? for me I checked around the oil filter and couldn't see any oil pooling up.

[JD.]

I cleaned all round the oil filter houses then went for a 15 min drive. My leak on the housing wasn’t a lot, but once it was clean it was easy to see where it started.

If it’s the oil filter housing or oil cooler there will be quite a bit of oil on the top of the V. Oil will pool on the driver side then make its way to the front passenger side of the V. The oil will then move to the back of the V on the passenger side to a small weeping hole. From there it makes a hell of a mess down the back of the engine & trans.