Sump leakage!!

[Johnny]

I recently decided to clean up the engine bay on my '64 traveller. It's got a 1098cc standard engine in it. Anyway whilst doing this I got a bit carried away and decided to change the head gasket, re-lap the valves, convert to screw on oil filter and take the sump off for a clean and have a good old general tidy up.

I changed to an alloy rocker cover and a pancake airfilter until I noticed the leak (home on a flatbed, again!). Read up on the issue and realised these are not compatible due to breather problems and loss of negative pressure ect so changed them back to the original ones.

Anyway I am still getting a leak from the back of the sump, through into the gearbox. I have changed the sump gasket three times now out of desperation all to no avail. I have not over-tightened it and am beginning to wonder if I have caused a more serious problem. I'm using the cork ones as thats what came off in the first place but I'm not really sure what to do next.

Any tips/help/offer of counseling greatly appreciated.

[David53]

I may be wrong, but from memory when I assembled my engine and box prior to putting back in the car the sump is totally seperate from where the engine mates to the box. When you say leaking into the gearbox what exactly do you mean? Do you mean oil is leaking from the block/sump gasket and running down the outside of the box? In which case it would prob be the sump gasket unless you have perhaps cracked the sump somehow with all the tightening....??

[bmcecosse]

If it's leaking into the gearbox - then it's passing the scroll seal (as suggested above) and nothing to do with the sump gaskets. Inspect carefully where the oil is actually leaking . If it's the scroll seal - then it's down to worn main bearings (too much oil flooding the seal) and/or high crankcase pressure - you MUST ensure at least one breather is connected into the carb to pull a light vacuum in the crankcase. If breathers are blocked - or piston rings are passing too much fume - then pressure builds and oil oozes out everywhere.

[DAVIDMCCULLOUGH]

Its probably leaking from the back of the crank, there is a screw thread which returns the oil. These can get blocked and not allow the oil to return and it leaks out at the bottom of the gearbox. thats what the hole with the split pin is for. The leak can be worse if the engine isnt breathing properly. I believe there is an update available to cure this but have never tried it myself.

I have found recently that the oil used makes a difference with leaks. Previously I had always used Duckhams 20/50 but decided to try Comma due to its price, the comma left oil deposits all over the place!! Going to stick with Duckhams

[Johnny]

Okay thanks guys.

When started up and left to run, when it has warmed up there is a tiny drip of oil that forms on the bottom back of the sump. I believe to the best on my knowledge that this has come from the back cork seal on the sump as it dribbles down. If I take her round the block a few times to check, when I have another look, its dripping from the bottom of the sump at the rear and from the gearbox hole with the split pin in. I am rather surprised as this didn't happen before I started messing around with it .

Also I'm using exactly the same oil as last time. The 20/50 classic engine oil. I think it's the Duckhams one.

Beginning to now think that with the valves properly lapped in, if the rings aren't up to it this might cause the excess pressure in crank case maybe?

Am I now guessing its an engine out job to sort and check?

[Declan_Burns]

Johnny,
Look at my previous post on this issue:
http://www.morrisminoroc.co.uk/index.ph ... ght=declan
The cork seals are in my opinion a waste of time. My engine does not leak anymore since I fitted the rubber seals. I only get a drop or two of gearbox oil coming out of that hole with the split pin per week.

[aupickup]

rubber or cork seals are as good as one another
remember to leave only about 3mm protruding above the sump on the seals or they will not compress properly and there fore cause a leak

[Declan_Burns]

"rubber or cork seals are as good as one another "

I see that differently, but that's just my personal opinion.

[aupickup]

i have used both and never had a problem with both

[bmcecosse]

Cork is fine - if left with enough overlap so they become compressed.

[Johnny]

Yeah thats what I thought. I've trimmed them down put it all back into place and it's still leaking which is why I am now thinking it's something else maybe.

It really is infuriating! short of taking the engine out (which is now looking all the more plausible) I'm at a loss what to try next.

Many thanks to all for replying though.

[aupickup]

is it def leaking in that area or is it leaking from the gearbox bell housing where the split pin is

are all the bolts torqued up correctly

i have noticed that some sump gaskets are a bit on the short side at the back
repro ones anyway

try and get old stock if u can

also check that the sump is straight in that area as well as sometimes the half moon peice needs to be filed down flush with the sump

also when you say leaking how much is a leak, is it a few drops now and then or a steady flow

[Declan_Burns]

I was so frustrated too. I tried the cork at least three times. The rubber worked straight off-it's worth a try before taking the engine out!

[aupickup]

by all means try the rubber seals, if you can get some they are a bit hard to get over here
you may have to buy midget or ital sump gasket set to get them

if it is a breathing problem it wont matter if its cork or rubber

[Declan_Burns]

I bought them here for a few Euro's from a local Mini specialist. I have seen the complete gasket sets on ebay UK. I can't imagine they would be scarce in the UK.

[bmcecosse]

What advantage will 'taking the engine out' have ? Can't see that making any great difference ! What will you do with it once it's out - put it back in again?

[aupickup]

[Johnny]

No its a serious stream out once its warmed up and been round the block a few times. It'll start as a small drip from back of sump leaks down from half moon. I take it round the block a couple of times then it will drip from bottom where bell housing meets back plate, anymore will result in it streaming from hole with split pin.

Well I was going to take the engine out, take off the back plate to check the gasket on the oil pump and replace the oil pump while I was at it. Just wanted to alleviate all possibilities really.

I found this -'MG Midget Mk3 Sump Gasket Set' would this suffice? There appears to be both cork and rubber pieces in this kit.

[Declan_Burns]

Johnny,
Read through my previous thread where I mentioned running the engine with the car over a pit and everything cleaned up so that you can really locate the leak. What you describe seems exactly the same as what I had. The cork would seal until the engine warmed up and then it started to flow. You really need to see where it's coming from. If it drips from the hole in the bell housing then, as mentioned above, it could be breather related. In that case there is a kit available to retro-fit a seal on the crank. This I also did and it's engine and / or gearbox out-mega work. And the sump still leaked! Believe me it's worth a try with the rubber seals before you start taking out the engine.

[eastona]

What advantage will 'taking the engine out' have ? Can't see that making any great difference ! What will you do with it once it's out - put it back in again?

Is that like a Microsoft Engine, do you have to uninstall and reinstall it?!

I'd try the rubber gasket, unless you enjoy taking the engine out. If you do, I've got one that needs doing!

That and check the breather is fitted correctly. Take the oil cap off while it's running and check if the engine is "breathing" heavily.

Andrew