Audi Q7 3.0t Engine Oil Leaking?
Hello Group -- We have a 2012 Gas 3.0 Q7 that persist to leak engine oil from the rear of the motor. I am specifically looking for information or ideas from somebody that has experience with this engine leaking... We service a lot of these at my shop but have not previously ran into one like this. Initially the engine had a failed crankcase breather causing excessive negative pressure in the crankcase. We replaced the breather and removed the transmission to address oil leaks. We replaced the rear main seal, oil filter stand gasket and re-sealed both upper timing covers (all were found with leakage) Afterwards the vehicle was cleaned and degreased thoroughly. We had the customer return after driving 1500 miles for re inspection. Again there was oil leakage at rear of the motor / bell-housing area :(
It is very difficult to see exactly where the oil leak is coming from... We are suspicious it may be coming from the large center timing cover or the upper oil pan, but in our experience these items have not been a issue as use silicone sealant from the factory and usually dont leak . We are planning to remove the engine assembly this time and we want to be the best prepared we can be... ANY THOUGHTS OR IDEAS APPRECIATED.
We have done timing cover reseal for oil leaks, so they do leak.
Bill, we have resealed a center timing cover once. But, we have had the upper covers warp enough that they won't not seal. Also have had a valve cover gasket leak in the back corner- the oil will run back along the bottom of the upper timing covers. We actually have a Q7 CJW on the ground now! Good luck
Oil filter housing. They leak terribly and go right in between the bell housing and the block then comes out the bottom making it look like a rear main or t-cover leak. Edit: can't read apparently.... I see now that you replaced the oil filter housing gasket, in my experience, that is almost always the culprit tho. Only other thing I ran into once is that when I replaced a rear main seal, the…
We had one that was a nightmare since we did the chains and tensioner's. We used the recommended silicone but could not stop the leak until we replaced the timing chain cover. I cringe every time we have to do a 3.0 or 3.2 chain replacement now.
When you say gas is this petrol? We have issues in the UK with diesels leaking from upper or lower sump, rear main or not enough thread lock on flywheel bolts. Any of these reuire engine removal so typically quote to do the lot in one go
I have a couple times found, the pcv system to be faulty, building pressure and blowing out the rear main. Granted it was the 2.0t in the vw. Maybe a vw guy can shed some light. And apparently I don't read well either.
UV Dye. Depending on the rate and amount of the leak, have the customer return in 50/100 miles (Good Luck with that) or drive it yourself. I've found if I know I'm going to disassemble anyway in the very near future, the UV dye used for a short time makes it easier to spot the source/location, especially in areas difficult to see. The dye is particularly helpful when you're working with clean…
To those that have resealed the large center timing cover on this engine are you also resealing the upper oil pan while your there??? How about replacing the bell housing bolts (service manual states you can use only twice) also how about the flex plate bolts as they are torque to yield. Thanks for your time we will starting this job mid week
When we have done them it was sealing timing chain cover, new rear seal and seal cam covers. We do replace flywheel bolts but not the bell housing bolts. You may want to consider chains and guides if the mileage warrants it. Would hate to come back and do it a second time. Pay close attention not to damage the layered head gasket were it meets the top of cover. If it moves when reinstalling…
We did not have to do the oil pan. Lew is right about the head gasket- pain to get cleaned out thoroughly. I recommend getting both flywheel and converter bolts. We had a couple flywheel bolts weaken as we did the final torque procedure.
Follow up after completing repairs-- We did put UV oil dye in the engine 2 weeks before disassembly. we found the lower left corner of the center timing cover had alot of evidence of dye. We resealed all timing covers and replaced the rear main seal. We replaced the flex plate bolts and had 2 bell housing bolts that broke (they are aluminum) this is a tedious job and requires a skilled…