Rob Parke

Hi! I知 new to this forum and this is my first post, sorry for the long read. Short version below at end of post.
I have a 2006 audi A3 with the 2.0 FSI. It developed a small oil leak last year and I have pretty much parked it since then. The oil leak appears to have started up high on the front of the block and runs down until it is spread all over the underside of the engine by the fans.
I assumed it was the oil filter housing as the oil appears to come from that area, the top of the engine is clean around the valve cover area.
I replaced the housing this weekend with an aftermarket part, it痴 a Chinese part but the seals looked good and the part appears to be good quality and identical to the original. I cleaned everything well and torqued the mounting bolts and cooler bolts to 15nm
I topped up the oil and coolant and let it warm up in my garage with no problems, I drove it back and forth up my driveway and after 15 minutes I noticed oil on the ground. I put the car back on jack stands and looked underneath. The majority of the oil was dripping of the aux water pump bracket which leads me to believe it痴 coming from the same area as before. There are small drips coming from where the engine bolts to the transmission looking like a rear main leak. This oil starts quite high on the front of the bell housing so it may just be running down from the filter housing.
I left the car on jackstands and ran it for 30 min, not a drop of oil came out while I was watching. 12 hours later not a single drop of oil on the floor.

I知 wondering if my pcv valve is shot? Could it be pressurizing my crank case under boost forcing oil out? I pulled the oil cap while running and it took a quite a bit of force to remove. There is a lot of suction there. My other thought is maybe if the crankcase is pressurizing then maybe oil is being forced out the joint in the dipstick tube? Anyone have similar issues? How can I test the pcv valve?

short version: car only leaks oil when moving, not when idling. I think the pcv valve is causing the crank case pressure under boost. How can I test the pcv valve?

Thanks!

findalex

Possibly. The PCV is a known weak component. Google for some videos on how to test if your PVC is bad. I had a TSI engine so I'm not sure if it's the same procedure with yours.

Rob Parke

I checked the pcv valve and I appears to be good. It blocked air in one direction but not the other. I checked that all the bolts I could reach were tight and tightened the oil filter. I hosed the underside of the car off and it has stayed clean and leak free for the last 24 hours. I知 hoping the oil I saw had just accumulated somewhere during the work and spilled down when I moved the car the first time.

findalex

Cool!