968to986

Hi there, I'm new to the 914 forum, though I've been a rennlister for other models for a while. I recently picked up a 75 914 that has a 1.7L engine. It's running good after a little work, but it has an odd oil leak. It can sit and idle without leaking any oil, even when hot, but when you rev it out to maybe 4K or higher, it starts spraying oil from the drivers side up near the block. I thought I'd ask here before I tear into it too much. It seems to be related to crankcase pressure. Any ideas to start looking for would be most appreciated. Cheers!

968to986

Well, in lieu of better ideas, I think we'll go ahead and drop the motor and see if we can find the source of leak. I'll post if I have any revelatory observations.

Last930

That's a tough one - there are so many places it can leak. As it only leaks at higher rpm when oil pressure rises I'd be looking at fittings in the block such as oil pressure sending unit that are subject to the pressurized oil. Look for an oil system diagram.

968to986

Thanks for the input. We dropped the motor and resealed the oil pump. It's tricky to diagnose because the leak comes from the drivers front of the engine, opposite side of the oil cooler. Valve covers, push rod tubes, cam seal, oil cooler all look good, so the oil pump seemed like a possibility. I hate to put it back in car without being sure, but short of running the engine out of the car, I don't think we can duplicate it without installing it again.

I'll double check any fittings on the block and reinstall tomorrow. Hoping for the best!

Last930

Any progress?

dr914

two things in that area are the front breather on the head and the thermostat roller bolt

fitzpac3

Took the car to a friends shop where he employs mechanics to work on his diesel fleet. One of his top guys, who is a blood hound for oil leaks took a look. He's certain the leak is coming from the oil cooler housing in between the top right bolt of the cooler as you are facing the side of the engine and the bottom right cooler bolt. This seems to make sense. I do recall Mike at Lindsey racing tell me the discovered a bit of pitting where the oil cooler housing mounts to the block when they were boring and honing my block. They added some epoxy to cover the imperfections and sanded it down. Wonder if I should use some rtv?