LSX Man

iTrader: (1)

I put a ls1/t56 in my 91 camaro. I took the ls1 down to the block and freshened it up with new rings, bearings, gaskets, etc.

The car slowly drips oil while running, and will leave 12" puddle of oil on the pavement after it is parked. I went through almost 3 quarts in under 70 miles. It leaks between the bell housing and block.


I remember replacing the rear main seal, and it was a pain. It was very hard to go all the way on the crank and sit right, however I do remember feeling that it was on the crank correctly once installed.

Oil pressure sensor is not leaking.

With all that said I want to yank the transmission for the LAST time. So what Ill should I replace to eliminate the problem, and any other potential problems. Clutch/flywheel is new.

I am thinking

Rear Main Seal
Pilot Bushing
Crank Plug.

And I have a strong assumption that it is the rear main but could be wrong. All of the oil pan bolts are tight.


Will a mis aligned oil pan gasket cause it to leak at the rear?

What do you guys think?

Burken01

iTrader: (88)

What procedure did you use to align front/rear covers and oil pan..?

Exidous

iTrader: (11)

Did you use RTV at the four joints between the pan and front/rear cover gaskets? The back of your flywheel will have oil all over it if the rear main was really that bad.

mikesimpalass

I kinda think that when you install the oil pan and front and rear covers, you need to bolt everything up loose, tighten the oil pan down first, then draw the rear cover down on to the oil pan. Then tighten up the rear cover bolts. If you don't get the two drawn together, the oring between the oil pan and cover won't compress. that's my guess

crainholio

iTrader: (2)

I think the guy that assembled it didn't know what he was doing.

LSX Man

iTrader: (1)

The oil pan was installed with no RTV. I placed the gasket onto the pan, and tightened the bolts in a cross pattern. Then torqued to spec. Maybe the problem lies there?


Crainholio, yeah, your probably right. It was my first time putting a motor together. But after rebuilding the entire car by myself, bumper to bumper, and having just an oil leak, I'd say I did a decent job. Especially at my age. Quite a learning experience.

crainholio

iTrader: (2)

See my signature.

JakeFusion

iTrader: (7)

Did you crack the pan? When you install the pan to the block, you have to use a straight edge to verify the pan to bellhousing clearance with a straight edge. Otherwise, once you torque the trans, pop goes the pan.

Also, you need RTV black on both the front and rear seal where they meet the pan. The gasket is not enough in those areas.

oldecmech

I too had an oil leak that almost drove me crazy. New f-body oil pan on a 5.3 in my '59 El Camino. I finally found a very small pin hole in the pan up high, behind the oil filter. A casting flaw. I had the engine in and out several times thinking gasket, main seal, even flywheel bolt seepage. Couldn't believe that pin hole could leak that much oil. It looked like it was coming down the long rear pan bolts. I am not pulling the engine again. Cleaned it with a micro burr on a dremel tool, brake cleaner and compressed air several times. Gave it the JB Weld treatment and let it cure for one week before adding oil. So far so good.

gMAG

iTrader: (1)

This is a very likely culprit...especially at the rear.

mikesimpalass

Why is the rear more likely to leak than the front?

gMAG

iTrader: (1)

Mike, my take is that the rear of the engine sits at an incline compared to the front. Where the permatex would go, at the two side/rear locations, is also a convergence of the bottom of the rear cover and the bottoms of the rear cover gasket, the two side rails of the oil pan, and also the rear of the block.
Mine is apart right now, and I could understand how, without that permatex seal, that oil would flow right through to the outside.
There are other possibilities, like the rear main seal.

gMAG

iTrader: (1)

(crainholio)
Psychology Today studies LS1Tech "please help!!" posters:
"The Dunning-Kruger effect describes a cognitive bias in which people perform poorly on a task, but lack the meta-cognitive capacity to properly evaluate their performance. As a result, such people remain unaware of their incompetence and accordingly fail to take any self-improvement measures that might rid them of their incompetence."

At the risk of sounding political, this reminds me of a certain Chief-Executive, and the people who voted for him.

S10xGN

iTrader: (11)

I had this problem on my LS motor that I bought used and didn't run for a couple years. It ended up with a carb and aftermarket valve covers. Turned out to be nothing more than a non-vented crankcase pushing oil out the rear main seal, once I put breathers on each cover the leakage stopped. So, check you PCV system or even leave the oil cap off for a day and see what happens...