86 with no oil pressure

[Chuck Rice (32205)]

A friend just picked up an 86 coupe with 82,000 on it and all seemed to be well until he was playing with it and lost oil pressure.

It doesn't appear to be clattering or knocking, but when he starts it now, the pressure will go up to about fifteen or twenty pounds psi and then slowly drop to zero.

It also started to leak oil just before this, so I'm wondering if he has a rotted or squashed valve cover gasket, would that cause the engine to show symptoms like this?

He obviously hasn't run it since but doesn't know where to start.

I haven't been near the car and haven't a clue to how a C-4 is setup.

Any ideas from the brain trust?

Thanks,

Chuck

[David Morland (42626)]

Re: 86 with no oil pressure

Hows the level? Hook-up a known good external hand held pressure gage(available at parts store) and start it up (for seconds!) you should see oil psi immediately. If so the gauge sending unit or gauge is bad or lost its ground. If not time to yank the engine and have a look.

[Chuck Rice (32205)]

Re: That was my first reccomendation Dave

Get under the hood and hook up a mechanical gauge as well.

All that digital stuff is pretty scary I'll tell you what!

Would a spun bearing do this?

Thanks Dave

[David Morland (42626)]

Re: That was my first reccomendation Dave

Ya, if the bearing is spun hard enough it will migrate right out of its shell. That will cause quite a psi drop. But you'd most likely hear a nice deep lower end knock(s). I like to follow the general trouble-shooting laws. Start with the easiest, simplest, most obvious path. Drain the oil and look for metal. Run a flexable magnet around the bottom of the pan through the plug hole. Cut the filter open and look at the materials caught in the pletes. Refill it and put that mechanical gauge on it. PSI tells the health of the engine both oil and compression.

[John Orefice (30543)]

Re: 86 with no oil pressure

Hi Chuck

I agree with Dave. Buy a mechanical oil pressure gauge and hook it up to the engine. The fitting should go where the electronic gauge fitting goes. Start engine and you should have your oil pressure.A leaking valve cover gasket won't effect it like that.If you show NO constant pressure then you most likely spun a bearing. You would then have to drop the oil pan and take each bearing apart to see which on spun and pray that the crank shaft did not get damaged.I had this happen to my truck and the crank shaft was badly damaged.

Good luck..............John

[Chuck Rice (32205)]

Re: Thanks guys

As I'll probably be the one wrenching on this thing, I'll start with the gauge and cross HIS fingers.

I'll get back to the group with the results .....good or bad.

Thanks again,

Chuck