Oil Pan Gasket

**pajeff02** · 05-15-2011, 02:28 PM

Found the source of my minor oil weep after pulling the transmission this afternoon. Looks like the oil pan gasket is leaking along the back rail. The rear main seal, rear cover plate, and OPSU are all clean and dry. I will be dropping the K-member to swap that out to a UMI tubular unit, so I may as well go ahead and change the pan gasket while I am there. The pan bolts are definitely snug, so that is not the issue.

Any benefit to attempting the gasket swap with the transmission out versus in? Obviously, the bottom two bell housing bolts need to be out. Not sure about how to safely support the engine except for under the balancer and at each back corner with an undercar stand. If I reinstall the transmission first, I will at least be bolted into the body so I do not have to worry about it rotating or falling completely out. Thoughts?

**Knight** · 05-15-2011, 02:41 PM

Not sure if it would be possible for you, but I have supported the engine from the top side via chain hoist or cherry picker - with the tranny in. Provides a very solid situation. It also allows total access to everything under the car - as I always seem to place the stands where needed, yet always in my way

**pajeff02** · 05-15-2011, 03:25 PM

Forgot to mention -- the car is 6' in the air right now and until I get the trans back in I have no way to lower it.

**JayTA98** · 05-15-2011, 07:41 PM

I had this same issue. I replace the gasket and even put the dabs of RTV and I see a leak on the back area of the pan. I remember checking with my fingers above the pan towards the RMS and didn't notice any oil.

I also heard that if you do the LS6 valley cover conversion can help with oil leaks because it lower the pressure. I might do that next before I give up with these leaks.

**tatertot91** · 05-15-2011, 08:25 PM

i got a brand new gm oil pan gasket if you dont have one

**pajeff02** · 05-16-2011, 03:08 AM

Originally Posted by tatertot91

i got a brand new gm oil pan gasket if you dont have one

I was going to check with the stealership today. What are they constructed of? It looks like a white/gray plastic type material.

**JayTA98** · 05-16-2011, 03:25 AM

Originally Posted by pajeff02

I was going to check with the stealership today. What are they constructed of? It looks like a white/gray plastic type material.

It is made of aluminu, no plastic at all

**pajeff02** · 05-16-2011, 03:29 AM

Originally Posted by JayTA98

It is made of aluminu, no plastic at all

If I recall, the LS1 literature states that the oil pan is an integral structure of the engine block. Must be that is why they use an aluminum gasket rather than neoprene. Probably why the darn things leak too...

**JayTA98** · 05-16-2011, 08:43 AM

Originally Posted by pajeff02

If I recall, the LS1 literature states that the oil pan is an integral structure of the engine block. Must be that is why they use an aluminum gasket rather than neoprene. Probably why the darn things leak too...

beats me. the inner part of it has a rubber gasket. i just know that I torque everything to specs and it's better than before but is still leaking.

**pajeff02** · 05-16-2011, 09:50 AM

Originally Posted by JayTA98

beats me. the inner part of it has a rubber gasket. i just know that I torque everything to specs and it's better than before but is still leaking.

That is not an encouraging sign.

**allbaugh_04** · 05-16-2011, 11:04 AM

Mine leaks too, seems like it's going to be a real bitch, that's all i know.

**oldmano2z** · 05-16-2011, 04:32 PM

engine specs. because of it being a structrual part dont forget to line up the back of the machined part of the oil pan to the flat machined part of the block with a straight edge there should be only twenty thousands gap between the edge of the oil pan and edge of block.

**JayTA98** · 05-16-2011, 04:47 PM

Originally Posted by pajeff02

That is not an encouraging sign.

lol im sry but if its not leaking alot i won't do it again. just my 2 cents. you might get lucky!

**JayTA98** · 05-16-2011, 04:49 PM

Originally Posted by oldmano2z

engine specs. because of it being a structrual part dont forget to line up the back of the machined part of the oil pan to the flat machined part of the block with a straight edge there should be only twenty thousands gap between the edge of the oil pan and edge of block.

I wonder if putting RTV around the gasket when installing will help minimizing future leaks.

**allbaugh_04** · 05-16-2011, 05:06 PM

I wonder if slapping RTV on it as is will help

**JayTA98** · 05-16-2011, 05:09 PM

Originally Posted by allbaugh_04

I wonder if slapping RTV on it as is will help

I don't think so because it will be more superficial than a thicker coat but give it a try. make sure you clean the area real good.

**pajeff02** · 05-16-2011, 05:58 PM

Originally Posted by allbaugh_04

I wonder if slapping RTV on it as is will help

I actually considered this. Clean it really well and go at it with a bead of Ultra Copper RTV or another similar adhesive sealant.

**allbaugh_04** · 05-16-2011, 06:09 PM

I've considered it...

**wileyCoyote** · 05-16-2011, 06:48 PM

when you guys say the oil pan is a structural component, you mean it's designed so that the engine can be lifted by the pan?

also, i wonder if mine is leaking too - damn near every other potential leak point has gotten new gaskets w/in the last six months. wierd thing is the engine seems to be running very well (yes i have new plugs and upstream O2s), and my fuel mileage continues to get better w/ time.. is a slight oil leak ok?

**pajeff02** · 05-16-2011, 06:52 PM

The oil pan also provides support for the transmission and has to be properly aligned with the back of the engine block during installation. A leak that drips should be fixed imo. A weep that simply wets the underside of the engine, but does not drip, can be left alone... but must be watched as it will eventually turn into a drip in most cases.