Found An Oil Leak Today...

Tman · June 4, 2008

Noticed a little oil on the bottom left rear side of the pan. It appears the leak is coming from a cover above the oil filter. The cover has a "bump" in the middle of it and is fastened by 2 10mm bolts. Seems like I read something here in the past about an oil leak from there. I checked the tension on the bolts and found that one of them was just snug but not really tight so I tightened them both. Hopefully this will fix the leak. I'll have to report back after a few miles.......

jtruck618 · June 4, 2008

I would be off to the dealer with that problem. Let them know in case it is a problem after the warranty expires.

VMax2007 · June 4, 2008

Look by your starter motor. If you see oil here (see pic), it's your Crank Position Sensor o-ring. Common issue on these trucks.

Woodcutter · June 4, 2008

Take it back. Then keep an eye on it. Chances are pretty good the dealer won't solve the leak on the first attempt.

I've had the rear main seal and oil pan gasket changed. And I'm afraid to crawl back under to look again.

Tman · June 4, 2008

Look by your starter motor. If you see oil here (see pic), it's your Crank Position Sensor o-ring. Common issue on these trucks.

I know what your refering to here but I have a 5.3L. The oil filter is on the opposite side (drivers) of the engine from the starter. My buddy had the same issue with the crank sensor o-ring on his 6.0.

Controller · June 4, 2008

Had replace the rear main seal mine, no leak anymore!

VMax2007 · June 4, 2008

Had replace the rear main seal mine, no leak anymore!

Yep, me too. That was on attempt 2 of 3. Not sure it was ever leaking or not though. The CPS o-ring on the 3rd attempt fixed it and it has been dry ever since. Attempt 1 was oil pan gasket and oil cooler line manifold gasket. 0 for 2 on attempt 1.

Controller · June 4, 2008

Had replace the rear main seal mine, no leak anymore!

Yep, me too. That was on attempt 2 of 3. Not sure it was ever leaking or not though. The CPS o-ring on the 3rd attempt fixed it and it has been dry ever since. Attempt 1 was oil pan gasket and oil cooler line manifold gasket. 0 for 2 on attempt 1.

They got mine on the first try, so I was pretty happy about that, but they did have my truck for 2 days.

C & A s Dad · June 4, 2008

My 2002 developed a similar leak but it was the op gasket right where the oil travels through the pan to and from the filter. They fixed it but I had to diagnose it. After a great deal of research here and on another GM forum, I found the issue, printed the material off and took it to them. The agreed, replaced the gasket and dry ever since.

cerbomark · June 4, 2008

I had the crank sensor leak Vmax2007 shows, Fixed it 1 st try for a change. I m sure they try something small like that before they replace the rear seal.

LAGA · August 17, 2008

Looked on the garage floor this mourning and found a small spot of oil. I have 14k miles on my 07 VMAX and it looks like I have a rear seal leak. The oil is coming out of the seam between the block and bell housing. I hope the dealership can fix this on the first try.

nbscanuck · August 17, 2008

Looked on the garage floor this mourning and found a small spot of oil. I have 14k miles on my 07 VMAX and it looks like I have a rear seal leak. The oil is coming out of the seam between the block and bell housing. I hope the dealership can fix this on the first try.

Dealer couldn't figure out which was leaking, motor or tranny, too much dirt. So they have put in some dye, I'm back this week some time to let them have another run at it.