Oil Pressure/Leak

[Bunghole]

Hi folks,

This might be a simple one for some of you, but for me....no.

Took the '72 L24 for a drive yesterday after it had been sitting for about two weeks in the garage. Oil was leaking at a good clip (about a drop every 2 or 3 seconds. Also, the oil pressure gauge was pinned on the high side. I stopped and restarted the engine a few times and the pressure went back to normal (about 45 psi). I took it home and parked it in the garage and there was about a 6 inch puddle of oil under the car this morning and the intake side of the engine was covered with oil.

At first, I thought it might have been the valve cover gasket, but that seems like a lot of oil to be that. By the way, I had the valve cover off during the 2 weeks idle period while I polished it. Lots of fun. I did not replace the valve cover gasket as it is fairly new.

I also replaced the plug wires and initially swapped the 5 and 3 wires by accident. I quickly fixed it and it ran great aside from the oil.

Anything obvious to anyone. I'm no mechanic, so I appreciate any help anyone can give.

Thanks.

[panchovisa]

Strange that the valve cover would leak on the "up hill side". Of course the best thing to do would be to replace gasket. Could have been damaged during polishing.

Also be sure nothing has blocked oil return holes in top of head and that breather in valve cover is not blocked by polishing crud.

Check that threads for valve cover bolts have not pulled up from head (counter sink them slightly). Tighten bolts in a pattern a little at a time (don't over torque).

[Bunghole]

Panchovisa,

Thanks for the tips. What is the torque spec for the cover bolts?

Any benefit to running some sort of detergent through oil system and then draining and replacing?

If the leak isn't coming from the valve cover gasket, it must be a head gasket or something which means I'll have to pull the engine apart I suppose. Just thinking I might want to clean the oil system out before doing it. I don't know...just thoughts.

Also, the engine could probably use a rebuild. What does a pro job cost? Maybe with getting it bored? Any advice or thoughts?

Thanks again.

[panchovisa]

Don't know the torque specs, but it is not high. Remember the bolts are going into aluminum and you don't want to pull them out!

On old engines I'm not a big fan of trying heavy detergents in the oil, where do the bits of varnish/crud end up?????

Rebuild costs? Depends how much you do, how much machine work, what parts you end up replacing.

Get rid of the oil leak first, you may just find you don't need a rebuild yet.

[Ed]

Start by topping up the oil then drive it to a car wash. Use the high pressure hose to clean the engine. Then start it up and drive it home. Once you get home you should be able to see exactly where the oil is coming from. I would bet it's your valve cover gasket. You said it was fairly new but it might have gotten pinched or isn't sitting correctly. Replace it. The torque for your valve cover bolts is 5-8 lbs. If you do use a new gasket re-torque after a few days.

The price tag on an engine rebuild varies alot. You can spend anywhere from $1000 - $10,000. It all depends on what you want. A basic rebuild, bearings, seals, gaskets, and rings, basically a re-fresh, no machine work just a rebuild. Will cost you close to $1,000. If you pull the engine or leave it in the car will also be a variable.

How many miles does the engine have? Does it burn oil?

[Bunghole]

Car shows 60k on the odo, but I just bought it in February, so who knows. Doesn't burn oil, but was running really rich when I got it. I rebuilt the carbs, dropped the smog stuff, installed a pertronix ignitor, did a full tune up and advanced the timing for non-smog, and it was running better than ever with lots of low end power and all that good stuff.

Also, a compression test showed 150-153 across all cylinders. My understanding is that that's a bit on the low side, so that's why I was considering a rebuild.

I will take your advice on the new cover gasket after I try to track down the leak. Could that much oil make its way out of that gasket? I guess with how hard I was driving it, the answer is probably yes. I find myself working on it for weeks at a time, and when I start to lose motivation, I just need to get it driving again and the motivation returns :classic:

[Bunghole]

Anybody have any ideas on why the oil pressure would shoot up until I stopped and restarted the engine 3 or 4 times?

Thanks.

[seerex]

could only guess the sending unit might be going , or it gave a false reading , but I would think it would give you a false reading of zero pressure instead of overly high

[Bunghole]

That's what I inititally thought, but now I'm worried that a piece of the cork from the gasket made it's way into the works and plugged something up temporarily. Oh well, cork isn't abrasive...I'll just keep an eye on it. I've ordered a couple of VC gaskets from Motorsports, so hopefully that will do it.

Thanks.

[Ed]

If the oil pressure goes all the way up it's because there is a short somewhere in the wire that goes to the sender.

This is a way to test the guage. You ground the wire and if it goes all the way up then the guage is working, similar to the water temp guage. It might be a short or your sending unit may be faulty.