Where is my leak

[grantxx]

This is driving me nuts open to any suggestions or theory.

I have replaced valve cover gasket and seals, used new metal / plastic type gasket, used sealant both sides of gasket.

Oil filter adapter o rings done, new oil pressure sender - no leaks in this area.

driver side appears generally ok, am getting some minor oil weep around rear head gasket area, or where either no 6 plug is, some oil bell housing cover.

Passenger side has leak above sump, runs along sump join area and down onto sump plug, also blows back up near rear main seal and drips onto exhaust.

Rear of engine block from what I can reach is oiled, small drip sitting on exhaust manifold bolt.

I have cleaned everything I can reach from below and above, cleaned off sump, no oil around front of sump.

Overnight no oil on ground after cleaning and car only started and idle for 10 minutes, drive to work minor drip about size of 20c piece after sitting at work all day, drive home and next morning double the size drip on the ground. Apprears to be coming from passenger side of engine.

Car runs fine, no indication of oil in water or water in oil, temps are good, oil pressure appears normal / touch high, transmission fine and temp around 60c measured on return line.

Any theories really appreciated.

[anthonygubbin]

There are a few common places the 4.0 leaks. Front crank seal, rocker cover, sump gasket, rear main, oil filter adapter and the dizzy. If you haven't done the sump gasket yet it probably leaks. They are not hard to do but the sump can be damaged if you don't unbolt the front bolts of the lower CA's. If your going to do the sump gasket it's probably worth trying to do the rear main. But I would suggest getting a genuine seal kit for it. Only because it's not something you want to do twice.

Regards A

[anthonygubbin]

If your getting a leak on the passenger side; are you sure it's not oil coming out of the front diff breather? They sometime pressurise and oil can come out the breather.

Regards A

[grantxx]

I pretty sure is not diff Anthony, wish it was, it appears to be up near manifold side of block is showing fresh oil when I check next day

[grantxx]

Originally Posted by anthonygubbin

There are a few common places the 4.0 leaks. Front crank seal, rocker cover, sump gasket, rear main, oil filter adapter and the dizzy. If you haven't done the sump gasket yet it probably leaks. They are not hard to do but the sump can be damaged if you don't unbolt the front bolts of the lower CA's. If your going to do the sump gasket it's probably worth trying to do the rear main. But I would suggest getting a genuine seal kit for it. Only because it's not something you want to do twice.

Regards A

Missed this first time, disy is pretty good from what I can tell, yes sump is a question but as mentioned appears to be coming from above sump, front crank seal also done about 12 months ago when harmonic balancer was replaced and no evidence of oil up front of sump at all.

[anthonygubbin]

Might be the head gasket. That would be really annoying because if you have no other probs I doubt it would be something most would consider, since its would be a $700-$800 fix and that's doing it yourself.

Regards A

[grantxx]

That is also where I think it may be, but having never seen the layout inside this head I have no clue if it is even possible for the head to leak oil externally and have no other issues on the inside