rear main seal replaced.. still leaking

[96 Calais]

oil still dripping from around the rear main seal, had it replaced 2 weeks ago (seal was definately leaking before).. took it back & im assured it's not coming from the rear main although it's dripping from the same spot (back of engine infront of auto trans).. no oil around the rocker covers at all..

could be the sump gasket maybe?

would it drip from the same spot if it was the sump gasket?

sure, it's only a drip at the moment, but it isn't suppose to drip & it's only going to get worse?

Other than the general age of a car what can cause leaks?

200,000km's 3.8L ecotec if that helps.

I don't have a great deal of knowledge about car's but im learning fast & hope to put some input back into these forums in time
thanks again in advance for your help.

 

[Claudy]

I'd say sump gasket man ay

 

[azzfox]

Sump gasket, oil plugs (rare I'd say), cam or balance shaft welch plug. Or they may have scored the crank taking the seal out.

 

[96 Calais]

no real way to tell without taking it apart I suppose?

 

[Claudy]

Id replace sump gasket first coz it's not that hard to do and it's probly due for new one by 200,000kms anyway

 

[Cheap6]

What, exactly, was replaced? The rear main seal sits in a carrier that is sealed against the back of the engine block by a gasket. The lower part of the carrier also forms the rearmost part of the seal to the sump gasket. If the seal (to the crankshaft) was the only thing replaced, those areas may still be leaking.

It's been a while since I've looked at one but if I recall correctly the carrier is not located on any dowels on the back of the block. If the carrier was removed and refitted, or replaced, the carrier may not have been set up in the correct location. There are special tools required to do this in order to ensure that the carrier lower face sits flush - flat and level - with the lower part of the block and the seal is concentric with the crankshaft.

It may simply be that there is oil residue left higher up from the old leak. First step would be to wash the underside of the engine, inspect to ensure that it is clean then drive and reinspect and go from there.

The front seal in the trans. has also been known to leak.

 

[RX25SE]

These things are an abomination.
I have replaced the seal/housing assembly with the upgraded one from GM (including the sump gasket) and it still leaks.
A mate and I did his car 3 times using old and new style seals and replaceing the housing (he had a centering tool machined) and it still leaks.


I will attempt mine once more only, if it still leaks I'm going to sell the useless POS.

 

[96 Calais]

hey cheap6, as far as i know whatever is included with a rear main seal kit was replaced. it's under warrenty so if it's still leaking from there they can redo it.
she only started leaking about 4 weeks ago, well thats when i noticed the smell of burning oil at least.. the exhaust and sump was covered in it. having it still leak really bugs me because it shouldn't be leaking. it could be leaking from around the sump gasket i suppose but like you said it could just be left over oil which has slowly dripped down, ill clean it up today and go from there.

ive spent to much on it to sell RX25SE, well not the engine but the rest of the car.. i'd put a different engine in it before I sold

 

[RX25SE]

ive spent to much on it to sell RX25SE, well not the engine but the rest of the car.. i'd put a different engine in it before I sold

Fair enough.

I meant MY usless POS.

 

[Cheap6]

I just thought of another possibility. Is there (on both/either cars ^) any reason for a build up of crankcase pressure eg. a blocked/sticking PCV valve or blow by from engine wear?

(The PCV valve is between the LIM/runners and the UIM/plenum.)