Potential oil leak locations

[Warren Chen]

I have dropped my engine to replace the clutch and general R&R. Based on my records, the engine was rebuilt in mid-80’s and no other major engine work since.

In my 9-year ownership of the car, the engine has always dripped oil. No major leaks, just drips. But I never had the chance to chase the leaks and fix them.
Now that I have the engine out, I want to try to take care of them. (perhaps I should have put some dye in the engine while it was still in the car, run it and use a black light to help me pinpoint the locations….but too late for that now.)

I am hoping with the photos I took, all you experts can help steer me towards the right direction.

Cylinders/intake 1&2 look very dirty but cylinders/intake 3&4 look relatively clean. Does this mean there could potentially be a leak at the oil cooler and the fan is spraying the leaked oil onto cylinders 1&2?

Also, based on photos 5 though 8, could the 3rd piece be leaking as well?

Any other place I should look, seals I should change?

Thanks for the help.

[Mike Wilson]

Potential sources (some of which you have already identified)
Oil cooler
Temp and oil pressure sending units
3rd piece
Oil plunger screws
Oil pump cover
Push rod seals
Engine case
Front and rear seals
The screws behind the carbs on the side engine tin that go into the case
Generator stand
Oil breather can
Oil lines to/from the oil filter canister
Oil filter canister top

If the engine was still in the car, I'd clean the heck out of it, run it and see where the leaks pop up. Other than completely resealing the engine, start with the easy stuff, oil cooler, copper seals to senders, the front and rear seals, etc.

I'm sure more experienced members will weigh in and either validate or correct my suggestions. Keep us posted.

[Warren Chen]

Thanks Mike.
What is the oil plunger screw?

[Ron LaDow]

Thanks Mike.
What is the oil plunger screws?

I'm not Mike, but that is a common label for these two locations:

IMG_1824_3.jpg (66.33 KiB) Viewed 3578 times

And yes my company sells upgrades, since another common, not to say universal, leak source is the sump plate and/or rivet. The stock part is a really good design for a life of 8-10 years, and a source of parts sales, also...

[Mike Wilson]

Thanks for reminding us of the sump plate. I've replaced the ones on my engines with the Precision Matters sump plates. No, leaks! Thanks also for the pics of the oil plunger screws.

[Ernesto Cabrera]

Other potential leak sources:
Cam plug cap
Head nuts seals under the rocker stand
Case thru bolts seals
If the Solex carbs are seeping gasoline, it will look like an oil leak.
Check the accordion and the seams in the push rod tubes they can crack and leak there

Good luck
Ernie

[Ned Gorski]

warren
If it were me i would bench run it, if you don't have a stand use a old tire and some 2x4s or a peice of ply wood or a furniture dolly the short 4 wheeled type works well also $20 at harbor freight ( wood one ) or buy an engine stand Then buy a starter adapter plate they are like $100... http://www.ebay.com/itm/Porsche-356-VW- ... 1640765747.... .. seriously it only takes about an hour to set it up to bench or floor test run.. you can use your lawn mower or snow blower fuel tank just close the valve and swap the lines ..wiring is simple clean the motor put it back together .. let her run for a little then inspect, fix repeat until the leaks are gone.. and then you know for sure there is no crack under the oil cooler just waiting to let go ..i love bench testing motors its instant gratification.. not to mention you can see it from all angles and you know the problem is fixed when you put it back together.

i never needed it but i always keep a fire extinguisher handy just in case
Regards Ned

[David Lawrence]

Mike mentions the "engine case".
Over 40 years ago I had the same leak problem and tried all the solutions mentioned, none worked. I got a Magnaflux kit and tried it around the case near the oil cooler mount, there it was a crack about 1.5 inches long.

In case you haven't seen it here is a youtube video that shows how it's done: https://www.youtube.com/watch?v=llHg1ZEctgU.

[Wil Mittelbach]

As an aside, and while engine out, suggest you replace its antiquated steel 6-pass narrow-fin clogged oil cooler with a more efficient 5-pass open-fin Al cooler for better oil cooling and lower in/out oil and cooling air pressure drops.
In addition to the afore posted list of suspect leak sources, would also add prospective valve cover gasket leakage - quite common.

[Ron LaDow]

In addition to the afore posted suspect leak sources, would also add prospective valve cover gasket leakage - quite common.

Wil, I would hope by now that Vic's composite rocker-cover gasket, whether you get it from him or one of his dealers, has pretty much solved that problem.
Vic, you developed the thing; where should we get them to make sure you get your cut?

[Warren Chen]

Great info.

Bench running the engine sounds very tempting....

Also, cam plug cap, head nuts seals under the rocker stand, and case thru bolts seals were mentioned. Can these be replaced without splitting the case open?

[Dave Wildrick]

Great info.

Bench running the engine sounds very tempting....

Also, cam plug cap, head nuts seals under the rocker stand, and case thru bolts seals were mentioned. Can these be replaced without splitting the case open?

Among these 3 items, only the 4 head nut seals (O-rings) under the rocker stand can be replaced w/o splitting the case (edit: I'm probably wrong about the case through bolts, but I'd bet you have to remove a lot of things to reach all of those with O-rings on them).
Use silicone or Viton O-rings and do the head nuts one at a time, and re-torque to the proper value after each one. Probably would be good to re-torque all 8 head nuts in the correct sequence on each side of the motor after doing this. I did it successfully on my 65C with no issues.

Also, if your current oil cooler is not leaking, you should at least thoroughly hose the oily dirt off the cooling fins with solvent.

[Randy Mittelstet]

I didn't notice this one yet. The pulley seal is a common culprit. The usual sign tends to be a little oil pooling in the engine tin below the pulley after a drive.......which is turned into a fine spray on your engine.
It's an inexpensive fix even if you hire it done since it can be done with engine in the car. It solved my problem.

[Cliff Hanson]

Cylinders/intake 1&2 look very dirty but cylinders/intake 3&4 look relatively clean. Does this mean there could potentially be a leak at the oil cooler and the fan is spraying the leaked oil onto cylinders 1&2?

Based on the two photos of the oil cooler it looks like you have an oil leak up near the top of the cooler, maybe where the tube is bent toward the front of the car. The "fins" are full of oil and dirt from top to bottom, but mainly on the side toward the rear. I would think that the airflow would carry the oil toward the #3/#4 cylinders mostly, but maybe there is a fine spray of oil towards the RH side that is getting carried over to the #1/#2 cylinders. I agree that running the engine on a test stand would be good to determine where the leak is occurring and to make sure it is fixed before re-installation.

[Mike Wilson]

Looking at the pics, I think there are multiple oil leaks. Check out the 3rd piece and below.