axl3133

I have an 07 Q7 4.2. Has been slowly burning/ leaking oil for years, nothing major. Today it is pouring oil from the passenger side front of the motor,towards the bottom, car is also running very rough. Will only leak the oil when the car is on. Any ideas? Thanks

dreadlocks

Tow it to a mechanic if your unable to figure out what to do from here..

axl3133

I will if I cannot do it myself. Just wondering if somebody may have had a similar issue in that area. Oil leaks are obviously hard to diagnose.

dreadlocks

If its a big leak when engine running its likely a high pressure passage, which means dont drive it because something could be starving or its reducing pressure elsewhere, you can dye your oil w/UV reactive stuff and get in there and trace it to the source, but your likely going to need to take a good lot of stuff out of the way to do that and clean it up as much as possible.. since you've been driving with an oil leak for a while I presume everything is a mess.

I mean if your up to fixing the leak by all means do it, but I suspect if you were you'd not be posting here for advice and it'll cost you more to fix a vehicle you've half taken apart already.

axl3133

Was thinking about the dye...so sick of working on this car.

dukesean

I would guess it's oil filter flange 8 shape o-ring if you see oil came through the holes under intake manifold.
You'll need to remove intake manifold to change several o-ring and gasket.
It happens with all V8 that has oil filter on top of the engine.
There are some diy threads at RS4 or S5 sections. And a lot more on Touareg forum.
Other possible is upper oil pan or lower oil pan gaskets.
But you are loosing lots of oil when idle. I will bet it's oil filter flange.
Good luck.

axl3133

Thanks, the oil filter flange was replaced under warranty about 5 years ago, so this was one of my first thoughts as I know its a common problem. Whats confusing to me is the codes I am getting coupled with the rough idle. I will post the scan later, its on my laptop. Had 1 bank running lean (I replaced both high pressure fuel pumps), and lots of misfires. I was wondering if a bad crank vent will cause excess pressure then causing what was a minor leak to turn into a river through a seal.

axl3133

I am posting here to see if any other Q7 owners might have had a similar problem that might aid in my diagnostics. I have received tons of invaluable advice in the past from these forums. I don't work on cars for living, but I fix mine when they need it.

dreadlocks

the 4.2 engine was widely used in a ton of vehicles, the Q7 sub forum is one of the least DIY/Modder sub's on this site.. You'd likely have better luck if you widen your search.. try starting in the 4.2l V8 specific sub: https://www.audiworld.com/forums/4-2-v8-discussion-108/

I find for most Q7 specific stuff I find better info on like Touareg Forums, those guys DIY far more than these guys do.

axl3133

Thanks!