Oil leak

[JRhea]

1974 914/2.0 I'm trying to determine the source of a significant (Valdez) oil leak, about 1/2 quart or more per month, while the car is parked. I've replaced both sump screen gaskets, drain plug seal, and the large rubber o-ring and (2) small copper bolt cover gaskets for the oil temp sending unit. I wasn't able to replace the actual oil temp sending unit gasket(s) as the sending unit was too tight to easily remove.
I'm assuming that the sump are seals are the only ones that are submerged in oil when the car is parked.

Unfortunately I've not had the time to put the car on the lift to explore the source.

Any suggestions?

[Dave at Pelican Parts]

Oil pressure sender, up on top near the distributor.

Pushrod tube seals will drip on the exchangers and make smoke, not puddles.

Oil gallery plugs, but those tend to pop out and dump all of the oil NOW, as opposed to leaking for a while.

Thermostat pulley bolt. It's actually a through-bolt and goes into the case; it will leak a whole lot in right turns and drip for some time after.

The through-bolt in between the pushrod tubes. It can leak, especially if the sump retaining nut has been over-tightened. Note that the over-tightening most often results in a broken crankcase, so the leak is the least of your problems at that point.

Most leaks out at the cylinder head (e.g., valve cover leaks) create smoke, but sometimes they can miss the exchangers and drip on the ground. I had that happen once; the gasket has moved when I put the cover back onto the head.

The distributor drive can leak.

The oil cooler seals can leak. (PITA to replace without dropping the motor, but definitely possible. See our Tech Article on the subject.)

I'm sure there are more places that can and do leak, but these are what come to mind right now.

--DD

[94teener]

JR - tough to find the souce of these leaks with all that tin and other stuff in the way. Clean your engine real good one day and clean your garage floor of oil - run the car and take a look, and/or park it in the garage and note where the oil drips (puddle) is and that might help you identify the general area.

As Dave mentions - I actually did replace the oil cooler seals in situ tthanks to your article - and you are correct it is a pita but doable if you get lots of room under the car and have patience. The toughest part is getting enough clearance to actaully see that the seals are seated where they need to be - I used a long thin screwdriver to guide them in place and there is only just enought room to squeeze them in there. Now I can not recall if it actually fixed my oil leaks at the time since the engine came out and apart a short time thereafter. Cheers!

[JRhea]

Dave and 94teener, thanks for your thoughts. I'll get the car back on the lift again as soon as the global warming goes back into effect. The car has been cleaned underneath when I replaced all of the sealing gaskets and "o" rings. After careful inspection, if I can't find the source I'll drain the remaining oil and reseal those bottom ports and plugs. I'll uses some RTV along with the gaskets, whereas before I only used new gaskets and no sealer.

When I find the gremlin, I'll let you know.