Hi,

I have a 1988 IROC with the factory L98 350 engine and T700.

When I bought the car the sump was damaged and had a patched hole so I bought an after market chrome sum and a new sump gasket.

I replace the sump when I replaced the engine mounts, by lifting the engine and squeezing the sump in on an angle.

However, I have a problem where the rubber gasket does not appear to seat properly at the rear of the engine around the curved part there the main bearings and rear of the crankshaft would be.

I've tried it a dozen times, but when tightened the sump gasket seems to keep getting pushed out in the middle. The front seems fine/

Pictures attached.

Is this normal or am I missing something?

 

no, that's not normal, and yes, it will probably leak...
how are you putting it together?
you should be using the nifty little plastic guides that come with the gasket that screw in the threaded holes in the block to hold the gasket in place, then you put the pan up and try your hardest to tighten it down evenly..

 

Thanks for the reply.

Everything lines up ok, including the plastic guides.

It's fine when the sump bolts are lightly tightened, but the gasket pops out the rear when I tighten the bolts up more firmly.

It's a 1988 L98, so should have a single-piece rear main seal, but I'm starting to wonder if the two-piece rear main seal if different and whether I've got the correct gasket ?

 

Are you using silicone on the rubber pieces? If you are, don't. It will cause the rubber gasket to smush out, and it will leak.

 

looks like the wrong pan, the gasket will be a one piece and the lip on the pan will be flush with the rear man in seal adapter

 

Thanks for the replies.

It's a single piece rubberised gasket. It cost more than the sump and appears to be good quality.

I didn't use any sealer on the gasket.

@Tuned Performance - good point, it never occurred to me that there may be different sump for the one or two piece rear mains.

I thought the rear of the sump lined up pretty well with the matching surface on the engine, but maybe the one and two piece rear main have a different diameter?

 

There is a right hand and left hand dip stick notch and one piece and two piece rear main seals. One two piece rear mains there are two different size front gasket thicknesses.

 

The dipstick area matched up on the sump and gasket ok.

I'm thinking that either the gasket or sump was the wrong part, although my recollection is that the gasket mated against the block pretty neatly.

I was going to replace the damaged K-Member anyway and guess I'll have to remove the sump again to check this.

Might take the opportunity to replace the oil pump at the same time.