Sump oil leak

[daverubberduck]

Spoke too soon. Filled the engine with oil and ran it for a while, oil started leaking from the exact same spot (by the bolt at the front drivers side corner of the sump). I realise now that the thread at this corner was stripped because the previous owner had over tightened this bolt to try to stop the leak. So the stripped thread was not the original cause. This is depressing, I thought I had done a good job of repairing thread and replacing gaskets. I am now concerned about what the true cause is. Maybe the front cover gasket? One thing I noticed when changing the sump gasket was that there was a slight step going from block to front cover at that corner. Could that be the reason? Should I have put some RTV there? Has this happened to anyone else?

Dave

[Mick6186]

When rebuilding my engine I located the front cover loosely and while the gasket cement was sticky moved the cover around until the step was negligible then tightened the front cover bolts.
Mick.

[daverubberduck]

That's interesting, thanks Mick. So somebody didn't take enough care fitting the front cover. Is the best option to remove the front cover? Is that a big job? Would be preferable to just drop the sump again and apply some RTV, but I'm not sure if that will do it.
Dave

[Mick6186]

Removing the front cover is a big job, with plenty of associated setting up of cam timing included. RTV will probably fill any gap, and is definitely worth a try first. Make sure all surfaces are totally oil free. Its best to put on the minimum amount of silicone and let it dry a bit otherwise it will extrude out of the seal and may end up in the engine. I would put a decent film on, let it dry and then only use a thin film for the final assembly,
Mick

[rgh0]

Try to see where exactly the leak is coming from.
It could be a crack in the font cover, the sump gasket or between the front cover and back plate and block.

Depending where its coming from will depend on the fix required

cheers
Rohan

[daverubberduck]

Thanks both for the advice. I will try to see where it is coming from first before trying the RTV thing, as Rohan suggests. I don't believe it is a fault in the gasket because it is a new one and I was careful fitting it. I will let you know.
Dave

[daverubberduck]

The leak is higher up, coming from the join between front cover and back plate. I've tried to show where in the pics below (top one using a mirror). You can see that someone has applied black RTV to try and stop it. Now I need to decided whether I can attempt this myself. How big a job is it?
Dave

[Mick6186]

If I was removing and refitting the front cover I would remove the engine to do the job in order to be able to clean everything thoroughly. In order to give yourself the best chance of a rebuild without oil leaks the head needs to be removed so it is a big job and needs a good selection of tools and experience in engine building.
Mick.

[Mick6186]

With regards to where the leak is when my car was previously owned by my brother it had a bad oil leak from the same area as yours. He thoroughly cleaned the area several times with a degreaser and sealed the whole joint with silicone sealer. surprisingly this remained oil tight. A bodge but worth a try as a stop gap,
Mick

[john.p.clegg]

Dave
That oil leak is quite close to the head feed,maybe the head gasket when fitted was not flush to the front cover back plate but on it a little,I had this a while ago and got the same symptoms.

John

[rgh0]

If you want to try a temporary fix clean the area and use epoxy putty over the area of the join thats leaking pushing it into the join as hard as you can. It seals and sticks better than silicone.

cheers
Rohan

[daverubberduck]

Thanks guys for your input. I will think about what to do next, I hate bodges but it is an option for now. Rohan, you mention epoxy putty, would that not be difficult/impossible to remove later on? John, do you mean the gasket that goes over the cylinders, or the elongated ring of cork that goes over the front cover & back plate? What you say is interesting and I'm just trying to understand it.
Dave

[rgh0]

The expoxy putty chips off relatively easily when you do come to dismantle the front cover

cheers
Rohan

[john.p.clegg]

Dave
The copper ( or whatever ) head gasket has an elongated hole where the block/head oil-ways don't align properly , the head gasket should stop at the front before reaching the front cover,if the head gasket was a little to the front of the engine and there was a step,then there would be less pressure sealing the head gasket oil way.....I found this as I have a tall block and front cover spacer which makes it easier to get this sealing wrong..the oil then makes its way to the front cover plate and down the outside.

John

[Craven]

Don?t compromise the front pulley centring if you try aligning the front cover to the block line.
You could end up with an oil leak around the pulley instead!!
BTW, it?s almost impossible to get rid of the oil from any surface you try to seal, it continually runs down from inside, but it can be done.
Ron