Pinto 2.0 oil leak

[SteveG]

The engine in my S2 has developed an oil leak in the rear when it's running and hot, the leak stops when the motor stops. It's a drip, not a spray and while not a lot of oil it has the potential for making a mess. Using mirrors and an endoscope, the leak is definitely between the block and flywheel and I can see oil wetted areas but no obvious source. It's a Swift and the pan appears to be in good shape with no repairs and the pan bolts are tight. My question:
Is there anywhere on the back of the engine where oil can leak out other than the main seal and pan gasket?
I really, really don't want to split the car to find this.

Steve

[BeerBudgetRacing]

The main oil galley has either a ball plug or a tapped in plug. Could leak there.
Left side about half way between the crank and top of block.

[Purple Frog]

There is a reason one may see a Depends laying on the top of the diffuser.

[Rick Kirchner]

I once had a leak at the back, through the top stud in the block. There must be a crack in there somewhere. Some red loctite form-a-gasket fixed it.

[DanW]

Hello Steve,

I had a similar issue with a mystery leak on my Kent motor. I did a bubble check to find the leak. Warmed up the engine. I pressurized the lube system through the dry sump tank vent using 1PSIG air. Then I mixed up some soapy water and sprayed the back of the engine from underneath and through the timing port on the adapter. I found the gasket between the main seal holder and the block was weeping bubbles.

Regards,
Dan

[swifttiga]

Swift DB S2? make sure it is engine oil and not clutch fluid. Ask me how I know

[SteveG]

Swift DB S2? make sure it is engine oil and not clutch fluid. Ask me how I know

It is a DB2 and it is for sure engine oil. I'm torn between PF's Depends solution for its' simplicity and Dan's leak check for its' accuracy.

Thanks
Steve

[Steve Demeter]

I have a bag of diapers in the trailer. Of course have not had to use them in about forever since I have them.

I would wait until the next time the engine is out if it is just a minor drip.

Keep an eye on it in case it gets worse.

[BeerBudgetRacing]

I'm torn between PF's Depends solution for its' simplicity and Dan's leak check for its' accuracy.

Depends... The problem is if you actually know what's leaking you'll want to fix it. Which means splitting the car...

Also, might try these instead:
https://www.amazon.com/Disposable-Un.../dp/B06XS446GP

They lay flatter.

[SteveG]

So the leak became way, way worse, slinging oil off the flywheel making a big f'n mess...
I split the car and found that the oil is leaking from the rear main bearing cap, see following picture.

What's the proper fix for this?
FYI:
It's a Swift pan.
Rubber end seals
No pan gasket, lots of blue RTV
The leak location was filled with blue RTV on both sides. only right side leaked.
More questions...
Should I use cork or rubber end seals?
Should I use a pan gasket or just RTV?
To be redundant - What the proper fix for the bearing cap leak?

Steve

[Rick Kirchner]

There's a little wedge of gasket material that gets driven in there, along with a little bit of RTV with the excess wiped off. Is the pan designed to be used without a gasket? Its become fashionable to just use RTV but if it was meant to have a gasket that gap can be tricky to seal well without one as everything warps funny as it pulls together.

[tlracer]

As Rick said, there are small plastic/rubber wedges that fits into the holes at the side of the cap. They need to be pushed in quite tightly, but not that hard they deform.

Chances are the pan will be designed to be used without a gasket - just the two plastic/rubber C-shape inserts that fit into the bearing cap grooves. Where there is no gasket, it's important to remove the little tangs at either end of the inserts before fitting the pan. These are designed to locate into notches in the standard gasket, so will prevent the pan sitting tight without one.

A bead of RTV all around will seal - I've tried this and Hylomar, but with the latter it's absolutely critical the two faces are a perfect metal-to-metal fit or it will leak.

Check also that oil isn't just bleeding into that area from the crank seal - I'm not sure if it's just the picture, but next to the cap/block split line this appears to have a little rippled deformation?