I've found my oil leak... any ideas how to stop it without surgery?

Hi All,

I have found the oil leak I have been chasing for some time.

It's not somewhere that is easy to strip, seal and refit. removal of subframe, sump tray etc.

Any ideas?

There is no leak at idle, only when the car is at speed or load. Too small to ignore, not big enough to be a major issue aside smell and gradual oil loss.

any advice?

Is that the oil sump seal?

Not sure from the pictures but your description sounds like the front main crank seal. If that's the case it can often be the result of a worn oil pump so if you just replaced the seal you might find you are back to square one after a month or so.

Replacing the seal is reasonably straight forward, replacing the pump is anything but. The pump is an engine out or subframe drop unfortunately as the sump needs to come off.

Personally I wouldn't take the chance, when it happened with me I took the hit and got the oil pump done at the same time.

Is that the oil sump seal?

yup, joint between block and sump.

Not sure from the pictures but your description sounds like the front main crank seal.

I know. My heart sank when I thought it was coming from the crank, but cleaning and testing pinned it as coming from the joint between block and sump casing, where the arrows point. The pulley wheel and everything on the block is clear of oil and dry as a bone.. only the sump casting has any oil on it.

The reason it isn't above the sump line may be because its getting out past the seal, and the spinning pulley is flinging it away. Its either front crank seal or sump seal me thinks!. The first one is easy, the second is a large pita, easier to pull the engine out to fix than to try removing the sump in situ imo, I have done it! I would firstly make sure its engine oil not PAS, then do the front crank seal and hope its that! Crank seals are cheap, and its worth removing the timing covera an having a look, if theres oil sprayed liberally inside there it may give you more of a clue!

The reason it isn't above the sump line may be because its getting out past the seal, and the spinning pulley is flinging it away.

actually the wheels is dry as a bone.. the oil leaks onto the lug then runs down the base of the engine...

Its either front crank seal or sump seal me thinks!. The first one is easy, the second is a large pita, easier to pull the engine out to fix than to try removing the sump in situ imo, I have done it!

Actually - my mechanic had the sub frame out and the sump off - I visited it mid surgery. As there is no oil above the seal at all I'm pretty sure its this sump seal.

I would firstly make sure its engine oil not PAS, then do the front crank seal and hope its that! Crank seals are cheap,

It's not pas fluid - these are fine and not leaking. it's that joint..

and its worth removing the timing covera an having a look, if theres oil sprayed liberally inside there it may give you more of a clue!

I will do.. is this a sure sign of front crank seal?

In pic 1 if I'm seeing it right we have the rear of the engine to the right out of shot, the aluminium section of the sump (other ali and black steel deep section again further to the right) with the power steering pipes attached and then the pulley (in the darkness) and then further left ie in front of the crank pully AND the sump we have a bar (steering rack or rollbar) that's dripping with oil.

If the above is correct then how is oil leaking from a sump/block seal and going against the airflow forward to that bar (the bar shows significant drops not a light misting).

In pic 1 if I'm seeing it right we have the rear of the engine to the right out of shot, the aluminium section of the sump (other ali and black steel deep section again further to the right) with the power steering pipes attached and then the pulley (in the darkness) and then further left ie in front of the crank pully AND the sump we have a bar (steering rack or rollbar) that's dripping with oil.

dead right... that's the front of the block where you see the pulley wheel, and the oil is dripping off the oversized anti roll bar, but it's being fed from above.

If the above is correct then how is oil leaking from a sump/block seal and going against the airflow forward to that bar (the bar shows significant drops not a light misting).

I know.. It must not be as windy under there as it looks, or the airflow is pushing it directly onto the bar.

There is no oil forward of the block (where the arrow indicates) anywhere.

and zero oil on the main pulley wheel either; dry as a bone.

When I clean and dry everything and run the car there is no leak, when I run the car at 4k for 20 seconds and have another look there is weeping on the lower (sump) casting side of that joint between block and sump casting.

If your mechanic has had the sump off at some point in the past it would make some sense that that is the problem. My old UK spec shat 2 front crank seals and it doesn't look anything like yours - you can see where it's come from the seal when it does. Sounds like the sump wasn't sealed properly when replaced.

Ahh if your having a mechanic doin the work then by all means let him get on with it, I had my sump off before and it was such a pita! Yes, when I had a front crank seal leak I had oil on my cam gears and cam-belt

So I take it that the only way to stop this leak is to take the sump off and re-seal?

Yes, probably better by far to pull the engine and turn it upside down on a stand than try and leave in situ on a ramp and hold the engine in from atop, with both X members removed. FIT A NEW OIL PUMP at the same time!!!!

nightmare :-(

but I will get it sorted...

Plenty of brake cleaner, a good brushing, more brake cleaner, air line, more cleaner, blow dry, and a thick but neat smear of Loctite's Toyota Sealant over the crack may well cure it, with no dismantling at all. Not clever, not nice, but very quick and cheap. I know of at least three forum cars sealed like this, with the owners consent. I couldn't possibly comment who did such a "repair". It's awful stuff to get off your fingers, you should use latex gloves, (allegedly...).

I was going down this line myself ;-)

there is no seepage at all when cold...

I'm good with sticking stuff, having worked with resins and the like for many years...

I agree with your cleaning regimen 100%

Thanks C, will be coming to you for a quick geo setup when ryan finished with the syvecs install...

your bilsteins & springs still feel fantastic.

No worries, good luck with it Mike, the ones I have done have all been fine, luckily there's no pressurised oil there. I'll be interested to see how it goes, both leak and Syvecs wise

Why has the sump been welded up ??????

Thanks chris, I'll be interested in the syvecs too. If I bring it to for geo you can try it yourself.

Dude, mechanic took the sump off to cure the leak, dropped a wrench on it when it was on the floor, cracked it welded the crack closed them welded a plate over it.

Well done for spotting, you were the first!

I must admit, I didn't look at the photos. It must have been some wrench, are you sure someone didn't try jacking it up under the front of the sump? Would take a real big smack to crack it with it off and on the floor. Welding of that nature will have distorted it, that's possibly why you have the leak. It may need a good bead of sealant to seal it properly next time it's off. Personally I'd try and find an undamaged one.

I'd be cleaning and slapping sealant on it too, but if a time comes when you do end up wanting to fit another I have an undamaged one............

Yeah, I didn't see the damage before the weld, but i will fit a new one when I get the opportunity.

I cleaned the seam, over and over, used an inter spacial tooth brush, and I could feel a void in that section of the seam as the bristles of the brush got stuck in it. Filled it with sealant, wiped it clean. Tested it yesterday and voila, no leak anymore.

Happy days :-)