bah321

Just when I was about to get my first round of mods with my tax return, I find small drops of oil on the garage floor.

I got under the car (this was after driving)...couldn't really narrow down where the leak was coming from, at first glance I thought it could either be the oil filter or oil pan gasket. I have heard of faulty gaskets and really hope it's just the stupid filter, or maybe one of the oil pan bolts. I didn't touch the oil pan bolts, bc I would want to see which one is the culprit then take it out, re-seal. I Re-torqued both drain plugs and tightened the filter.

Anyone have a similar experience ? Am I missing anything ?

btw it is a 2006 Z06 w/ 16k miles.

Z11409

check for a crack in the oil cooler line at the fitting just above the oil filter

Morrisman

My 08 Z06 started leaking oil from the oil pan gasket after I went for a top speed run.

383vett

Some pans will weep oil. I think there is a tsb on this. RichieRich chime in?

bah321

Thanks for the responses, I will check the oil cooling lines.

I don't think it's the oil pan weeping, something is def leaking.

I guess I will know more when let it warm up w/out driving then get under there tonight.

I can fix everything else besides the oil pan gasket myself, don't have the proper tools....and I really don't want to fork over 1k for a gasket replace....ugh

Undy

Break out the black light, Jimi Hendrix posters and put some UV reactive fluid in the oil. Run it for a while and see what glows.

FASTBLUEZ06

I have a 2006 Z06 also, and I just recently noticed a couple drips on the floor... I jacked the car up to check it out, and the oil pan was mostly covered in a light film of oil and both drain plugs and the oil filter had oil dripping off of it. Could this be a leaking oil pan seal?

chasboland

I have the exact same situation on my 06Z. It seems to be fine all summer long, but when it sits in garage for the winter a few drops appear and the underside of the pan and filter get oil on them. I took it to the dealer a couple yrs back in the spring and they put rtv on the bolts and retorqued. I am used to it but it still is bothersome considering the caliber of vehicle it is or supposed to be. Oh well.... bring the spring on!

rikhek

On my 08 C6Z with about 25k miles the pan gasket was weeping. GM replaced the entire pan and new gasket under warranty about 2 months ago.

I couldn't believe they put a brand new pan on.


Rick

Luweegy

Headers are notorous for rubing a hole in a oil cooler line.

Turbooo2u

I have the same problem on my 07'. Hopefully I can get this fixed munder warranty this spring.

bah321

After further inspection over the past weekend, it is the oil pan gasket that is leaking.

It wasn't a huge leak, and it probably could have been tolerated for a while, but the gasket is most likely going to get worse over time. Taking it in this weekend. Wish I had the tools to do this myself.

Was planning to buy another f-body, looks like ill have to set that back for a while

mfain

Simply as another data point for those interested/affected. In May 2010 my 06 Z06 (purchased new in May 2007) developed the same seepage around 3 of the pan bolts. The car only had 815 miles on it (I know, my bad), but it had been started and run to get full oil temp about once a month. The 3 bolts, and several others around them, were under-torqued. My first guess would be that the pan gasket probably "shrunk up" resulting in a bolt torque change -- a condition aggrevated by the car sitting for long periods after the heat cycles. I re-torqued the bolts and the leak did not reappear by September when I traded the car for a new Z06.

EDHGB

Did you simply go around the oil pan front to rear or did you do an X pattern? What did you re-torqued them to?

Turbooo2u

In my case, the oil never hit the floor. It was just wet underneath.

mfain

The 3 bolts that had fluid on them were in a front driver's side corner of the pan, so I tightened them first -- no particular sequence, and I think it was 18 ft/lbs (I used the GM torque spec, but I don't have the book in front of me right now so check a reliable source). One was so loose I probably could have removed it by hand. I then started from the loose bolts and worked back in order -- the next three were just under torque, and the rest were okay. I couldn't reach all of the bolts with my torque wrench. I know that, on the assembly line, a single machine torques all of the pan bolts at the same time. That made me a little edgy tightening the bolts -- mostly a fear that perhaps an uncalibrated or malfunctioning torque wrench had stripped the bolt holes in the block. I removed one bolt and checked it for aluminum thread shavings -- didn't see a problem. I was very conservative with the bolt tightening, and I suspected it would only be a temporary fix. I also wondered if, with the car sitting for such long periods, I was getting enough oil drainback from the dry sump tank into the pan to submerse the pan rail. You wouldn't think that you would get a leak in that case, but with the engine running, the oil level in the pan is very low and there could be a slight negative pressure created by the oil pump that might mask a static leak.

crownu2

Yeah, mine was leaking on the bottom side of the pan bolts on the drivers side as well, I just put a little RTV on the threads of the bolts and also on the inface between the pan and the bolt re-torqued them and no leak since then!! Thank God!!

mfain

Talked to a Corvette tech in a large dealership today and he said they had replaced LOTS of Corvette oil pan gaskets lately, and not all LS7s. He said the new gasket was a "different color", perhaps (speclative) indicating a change in material or composition.

LowFlight

eaglei

If you have an 06 or newer Z06, you have a Wixom hand built engine. If this is the case then your oil pan bolts were not simultaneosly tightened. Rather they were tightened by your engine builder in two steps - first to 15 nm, then to 25 nm. We use an electronic torque system. And we follow a definite tightening pattern, from the center working out.

I'm no expert at leaks that occur in the field, but from what I've heard oil cooler lines are often the culprit. I've also heard of leaks due to pan porosity and leaks at the "T" joints where front and rear covers mate to the engine block, and mate to the oil pan. But I have no idea how frequently these leaks occur... But I do know that if anyone will notice it a leak it will be a Corvette owner. Many are kept in perfect condition, so why not expect perfection?