Oil Leak

[Plan B]

Hi all. This might be difficult to definitively answer but I'm hoping some of you can provide likely causes if not a definite cause. I've had this oil drip from the juncture of the engine and bell housing since I bought the car 3 years ago. It only appears after the car has been run and ends up as an oil thimble-full dropped and then no more till it is run again. I can sort of live with it when the car is garaged with a drip tray underneath but it prevents me from parking on my drive so now the time has come when enough is enough. Looking underneath - there is no oil pooling inside the bell housing under the clutch. Oil is however accumulating on the outside at the bottom of the bell housing case at the interface to the lower clutch cover plate. Looking up above that location there are oil drops waiting to drop on the two centre-most rear sump bolts. There is no visible sump gasket leak other than these two bolts having oil drops on them. As a first attempt to solve this I removed the sump and refitted using a good quality sealant (Dirko) and also installing a rear sump strap/bridge to assist in sealing the area where the two aforementioned bolts are. The problem still remains.

So here are the options as I see them:
1) Rear crankshaft seal - but would this not be dropping oil inside the bell housing?? However that isn't the case - there is no oil pool at the inside bottom of the bell housing.
2) Leaking valley/end gaskets - if this is the case which downwards route does any leaking oil take?
3) Oil leaking from the sump around the two rear sump bolts - any suggestions for plugging this without taking the sump off again? Being a lazy boy is it worth attempting to push a bit of liquid gasket into the bolt holes and replacing the bolts?
4) Any other possible causes to investigate?

I've got new valley/end gaskets and rocker cover gaskets waiting to go in but before I do I just want to make sure I'm not missing something obvious.
Comments appreciated

[Hedgehopper]

I had several failed attempts at curing a leak in this area. The sump was resealed, bridge plate and oil seal fitted but what finally cured it was new cruciform oil seals on the rear main bearing cap.

Hope it works for you.

[bluezeeland]

Mine does this, pretty sure its not the valley/end gaskets........it does it however only on 'winter' oil (5W40) not on 'summer' oil (15W50).....

Edited by bluezeeland on Friday 5th May 21:47

[Pete Mac]

Hedgehopper said:

I had several failed attempts at curing a leak in this area. The sump was resealed, bridge plate and oil seal fitted but what finally cured it was new cruciform oil seals on the rear main bearing cap.

Hope it works for you.

The Green Meanie does this, I've had the sump off 3 times. I looking at Hedgehopper's cure Pete

[lancepar]

Just an observation....
The oils in the engine and gearbox will smell distinctly different if you take a sample and sniff it.
And they will be different colours as well

So that should help decide which unit it is coming from at least.
Unless both are leaking that is and have mixed

[Englishman]

I've also had a very small oil leak on my Griff from the same area for quite a while! The amount of oil is so small that it doesn't leave any on the floor when parked, but you can smell it burning off a hot exhaust after a 100+ mile journey and there is some oil on the chassis/sump at the rear of the block. The sump was resealed a little while ago, so suspect the oil seal too.

[Plan B]

It's definitely engine oil that's dripping.
I'm still mulling over what to do. If I go for crank oil seal and cruciform gasket replacement which means engine out then I'll get camshaft/chain etc and clutch changed at same time even though they don't need to be done. House move is coming up for me so I don't want to start this job at home. Bespoke Performance is having an open day end of this month. I might get persuaded then. 😄

[Hedgehopper]

You don't have to take the engine out to do the crank oil seal and cruciform seals, of course you would have to remove the gearbox..

Rocker cover gasket is another possibility but it was the cruciform seals that finally cured my car.

[Plan B]

Yes fair comment - gearbox out would do it however I should have said I would get the engine bay heat shielding replaced as well - hence engine out.
Still mulling it over ..............