LSpann

Well guys I have a 2008 Z71 5.3 that has a oil leak coming from the oil pan or it could even be the rear main seal. A few years back I had to change the oil pan due to a crack. A new oil pan and gasket was installed and the leaks had stopped. But over the years I noticed the engine was losing oil and staining the driveway. While under the truck this morning I noticed oil on the rear of the oil pan and it was also on the sway bar thats near the oil pan. Are these symptoms of a rear main seal?? Being this is a 4x4 it looks pretty complex.

Are there any other things I can check that may be causing oil leaks?

LSpann

Today I replaced the oil dipstick tube with a dorman replacement. The old tube the mounting bracket was broke which allowed the dipstick to move around. While replacing it I flashed a light up the rear passenger cylinder head and I could see a path where it looks like oil was draining down...Could a bad valve cover cause a large enough leak to leak down the cylinder head?

repairman54

Yes Especially that you can see a path coming down. Don't forget that the engine tilts down at the rear so that's where all the oil runs back to.

LSpann

Ok thanks. I was able to put my hand between the head / valve cover on the passenger side rear and my fingers came out oily. Is there a write for this?? Or do i just unbolt the coils then remove the valve cover bolts?

repairman54

alldatadiy.com has the full shop manual for your truck. I have a subscription for each of my vehicles and I'm a very experienced wrench turner. It's good to have when doing your own work.

LSpann

This weekend changed both valve cover gaskets and changed the oil to see if the leak would slow down. I am still getting oil drops on the starter motor, a little between the transmission housing and oil pan. While under the truck I removed the transmission cover to see if oil would pour out and it was clean looking at the flywheel/torque converter.

im getting 40 psi oil pressure at idle..I was thinking maybe an oil gallery plug or something came out but I heard I would have 0 oil pressure if this occured??? Can someone point me to some other places where oil could leak...I'm thinking it's coming from the passenger side rear of the motor somewhere...

Can the valley cover leak or intake manifold leak oil?

repairman54

Oil pressure sender is on the back of the motor. They can leak and still work. Mirror on a stick is helpful when looking at the back of the top of the motor and other tight spots.

LSpann

I was able to get a good look at the oil pressure sender using my iphone everything seems to be clean back there. While checking for leaks I unloosed all bolts and removed the 2 skinny long bolts that go from oil pan to the rear cover. And loosened the transmission to oil pan bolts then retorqued everything just incase the pan was not aligned correctly. After all that I poured oil back in here and I could see a small line of oil leaking on the passenger rear of the oil pan. RTV was used in all 4 corners but I was thinking maybe I didnt allow the rtv to dry?

The only other thing I can think of that may be the issue is the oil pan gasket. It's a knock off Ultrapower brand.

black beauty

any luck?

mountainmanjoe

@black beauty
Please post a new thread with your vehicle info. Thanks.