spy2520

iTrader: (3)

Is that what this is? Or is oil from the pan somehow travelling up? This is on an FWD LS4.

spy2520

iTrader: (3)

My logic tells me that oil would not travel UP the rear cover like that. Opinions?

edit: and how frequently do these rear cover gaskets go bad?

01WS6/tamu

iTrader: (37)

Without pics kinda hard to see what you are talking about.
Yes the covers do sometimes leak.
If you pull the cover look very closely at the block for divits or pinholes in the sealing surface. We have seen several aluminum motors through the years leaking from the cover area only to find the block is porous. GM's fix via TSB is to put a layer of black rtv over the complete rear of block sealing surface then install a new gasket and torque the cover and that will fix the problem if it's a porosity issue.

spy2520

iTrader: (3)

My pics don't work? aww ****. I have 5 of them. Hold up.

spy2520

iTrader: (3)

pic links fixed i think.

JRENIGAR

iTrader: (37)

In the first pic I can see the oil level is above the pan gasket on the left side through the flexplate hole. id almost say rear main seal. Can u get better pics of the rear main to be sure. if not there maybe rear cover to oil pan gasket leaking.

spy2520

iTrader: (3)

spy2520

iTrader: (3)

With the flexplate off, it almost looks like its the pan gasket and all the oil is "wicking" up. The front and rear seal don't appear to have oil coming from them, the covers maybe. Still hard to tell for me.

trans_am7935

iTrader: (15)

Well since you got this far, and it is in a truck, i would replace both to be on the safe side, but i agree, that is what my oil pan looked like after i failed to torque it down properly after cam installation.

spy2520

iTrader: (3)

Its actually in a FWD car.

JRENIGAR

iTrader: (37)

Not the main seals. I think its gonna be pan gasket leaking on this one.

JRENIGAR

iTrader: (37)

Looks extra heavy around the oil filter area. Thats where the pressure is going from block to pan. Might be the biggest leak area. How is the engine oriented in the car? Is filter on front right of engine or What?

spy2520

iTrader: (3)

The filter is pretty much in the same spot most LS engines are I believe. Its towards the front of the car, since its front wheel drive. It was definitely leaking more in that area.

I ended up just changing the pan gasket as it seemed to be the problem.

01WS6/tamu

iTrader: (37)

You already have the trans out. Put a rear main seal and cathedral gasket and change the oil pan gasket. The gaskets are just too cheap versus the amount of PITA to re do it later on down the road or instantly just pulling at straws as to which is the culprit.

Be sure to check the cathedral gasket sealing surface on the block when you have it off.

JRENIGAR

iTrader: (37)

Just fixed a leak like this on my car 2000 t/a. Look at the top of the engine cover and see if there is a small void cast into the block where oil can puddle up. Mine done this on the rear cover right where the cam sensor goes into the block. I just ordered the entire rear cover with new gasket bolts and rear main seal already pressed in from Oriley Auto Parts for like $50. You can see in the 10th pic you posted the oil is coming from up top. It is on the side of the cover next to the block well above the oil pan area.