9 replies to this topic

[ashleyread1]

Hi, so i have rebuilt my engine like 3 times now to try to eliminate any possible oil leak. 

 

After this weekend i thought i had fixed it all. however after a little run it came clear i had not. 

 

it only leaks however once the engine is off and been left for a while to cool down and let the oil set. 

 

it seems to be coming from the rubber U which sits between the gearbox and the engine. 

 

has anybody had a similar issue and also is there a fix that can be done without removing the engine?

 

Thanks Ashley 

 

 

[Carlos W]

Is it coming from there or the timing chain cover?

[ashleyread1]

not too certain will look when i get home, cleaned the engine yesterday so should be able to let you know 

[tiger99]

Purely for information, this is commonly known as the "half moon" seal. Have you fitted it the correct way round, and remembered a little bit of silicone sealant at each end where it meets the main block to gearbox gaskets? I can't see why else it might leak.

[Carlos W]

The timing chain cover is often an issue.
Good luck

[ashleyread1]

think it is leaking from the timing chain cover, possibly from the oil seal on the case 

[Rob Gavin]

well that's a little easier to deal with then if it is

[ashleyread1]

Yeah, at least i wont have to take apart the hole engine unit again. i will let you all know 

[tiger99]

Did you centre the case on the pulley before tightening the bolts? And how is the pulley where it runs in the seal? There is often some wear which results in a leak. It is ok to press the seal in slightly less than all the way so that it runs on fresh metal. Or ideally get a new pulley.

There is also the theoretical possibility of a small leak between pulley bore and crankshaft. A very small amount of RTV will deal with that if it happens.

Had all that sort of trouble myself a long time ago! Even had to change a seal by the roadside. Fortunately although I was a long way from home, Redditch I think, there was a BL (shows how long ago it was!) dealer nearby.

Another thing to watch for in that area is that some crankshafts and/or pulleys were made wrongly and the bolt and washer bottom on the crankshaft without clamping the pulley. That does induce leakage between pulley and shaft and fretting of the key and keyway. Seen it on TWO brand new factory engines! The remedy, if spotted before any harm is done, is to add a washer whose bore fits over the crankshaft nose, then the normal washer and bolt.

[Carlos W]

In order to seat everything correctly you need to fit the seal, fit the pulley in place through the hole, then fit the whole lot to the car with the gasket obviously. This ensures the cover and seal are correctly sat on the pulley.

 

It's also worth ensuring the cover is flat on the gasket surface and not damaged but you should be able to tell if the oil is coming out of the seal or out of where the cover meets the front plate.