2002 LS1 rear main leak

[johnfin]

I did the clutch about a year ago, replaced everything including the rear main seal, used the special tools and put it in right but I still am getting a leak onto the H-pipe. No its not the sender unit on up leaking down. Does anyone other then GM make a real decent rear main seal?

[SMWS6TA]

Is the leak coming from the engine or the transmission? I asked because you stated h pipe. That should be just behind the tail cone of the transmission.

[johnfin]

Its dripping out of the bellhousing slot so I think once it gets out the oil trails back to the exhaust. I need to look at it again and take a pic.

[SMWS6TA]

Slave cylinder leak or transmission seal too are possibilities.

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Slave cylinder leak or transmission seal too are possibilities.

[johnfin]

Ok, i put it up on ramps and took a look. Its all wet with motor oil, not dextron. Side and top of engine are dry. Slave is new and not leaking. Left o2 sensor is dripping with oil, probably from the harness. I think its migrating from the bell housing back to the H pipe, it was wet. I will put some uv dye in the oil and check it. Pretty sure its the rear main.

[pajeff02]

What I thought was a rear main leak on our car turned out to be the engine oil pan gasket. It leaked out of the bellhousing and would drip on the garage floor. Changed the pan gasket and things have been bone dry ever since.

[johnfin]

Any way to check that without pulling it all apart?

[johnfin]

I used the uv dye. Not coming from slot in bell housing. Its dripping from the starter bolt up high on engine. No oil from heads up. Drips down the joint between engine and belhousing. Some of the cross main bolts look wet but this starter area is dripping bad. Any ideas?

[johnfin]

Took starter out and flywheel is bone dry. So if it was the crank plug, rear main or cover, wouldnt it be wet in there? And if the rear cover leaked i would think it would go into the bellhousing and out the slot which its not. Unfortunatly i think i need to pull the transmission.

[pajeff02]

Leaks are tough to locate as air turbulence pushes the oil around. You could try removing the accumulated oil with brake cleaner to better track the source. Possibilities on that side would be the OPSU, a failed PCV hose, the oil pan gasket and the low oil sensor.

[johnfin]

Where is the low oil sensor located? Iam thinking its the rear cover leaking and coming out thru the hole in the side of the bellhousing where the starter is.

[johnfin]

The pcv wont dump a bunch of oil, right. Its a breather.

[SMWS6TA]

Depends on how bad it's cracked and how much blow by you have.


The oem PCV is a POS (and that is me being nice in description).

[pajeff02]

Where is the low oil sensor located? Iam thinking its the rear cover leaking and coming out thru the hole in the side of the bellhousing where the starter is.

Passenger side of the oil pan.

The pcv wont dump a bunch of oil, right. Its a breather.

I agree - it is designed to be a breather. In reality, the stock PCV system sucks oil out of the engine and dumps it into the intake. If the hose is cracked -- which is a quite common, especially with the age of our cars -- accumulated oil in the hoses can drip and run down the back of the engine. Our aftermarket catch can will usually have around 1/4 cup of oil in it when I service it.

[SMWS6TA]

Since I've had my LS6 VCT I've yet to have much oil in my catch can. I'm thinking about just removing it all together.

[pajeff02]

That's great - always wondered what the actual difference in oil draw would be. Catch can is a must on any LS1 with the stock PCV setup imo.

[SMWS6TA]

I checked it again this past weekend and to be honest I've forgotten to in the last 3 oil changes. Had less than a tea spoon.

And in that time I've had 4-6 track days.