Oil pressure concern

12 psi is pretty low. I wonder if the bypass is opening when warm? Have you tried another oil filter?

The oil filter is definitely on my mind. Might try changing it just for the heck of it.

The sh> >

Experimented on my machine today. Duplicated the highway run that produced the flickering oil pressure light. Stopped and checked idle oil pressure. It was 10 psig. Shut engine off. Oil level was normal. Obviously it was not low when I put in a quart of oil the other night, because I had to remove a quart today to get it down to the full mark on the dip stick.

Put on a new oil filter. Exact same results as before after revving the engine in park for about five minutes. No idiot light, but pressure was 10 psig at idle. Checked idiot light on the bench. It appears to close at about 4 psig decreasing as the spec says it should.

Any more thoughts out there?

Pickup tube cracked Pressure relief valve stuck open Totally worn out pump way out of spec

Probably has something to do with driving through Wheeling. Kind of like the Bermuda Triangle theory. Stay east, like in Lombard or Villa Park.

LOL

========= Harryface =========

1991 Pontiac Bonneville LE 3800 V6 ( C ), Black/Slate Grey _~_~_~295,558 miles_~_~_

~_~_~_~_U.S.A._~_~_~_~_~_

~~~The Former Fleet ~~~

89 Cavalier Z 24 convertible 78 Holiday 88 coupe 68 LeSabre convertible 73 Impala sedan

Do you have oil around any of the gaskets of your motor. I had a 1995 grand am with quad four. At 137000 miles I sold it because it was leaking oil from either valve cover gasket or head gasket. Never had the oil light problem though unless I was low.

No leaks on this machine. Very dry. Virtually no oil consumption form one oil change to the next.

You must be speaking of Wheeling, Illinois. My Wheeling is in WV. Might be similar though.

bearings worn beyond help GW

Is this the same engine that you worked on a couple of years ago? Any chance coolant could have gotten into the crankcase through the cracked head? How are the cam bearings? If necessary, you could plastigauge the crank. The caps will have to come off anyways to inspect the journals. Check the clearance of the oil pump gears, too. Replace the oil pump pressure relief before doing anything else.

This is not the same car as the one I rebuilt a few years ago (your memory is a good one). This one was my other daughter's car until she gave it back to me late last year.

This machine does not use cam bearings. No evidence of coolant loss. No evidence of coolant in the crankcase. Oil usually looks pristine.

What concerns me about the in-car checking using Plastigage is that the crank shaft will be resting on the "bottom" of the main bearings, and the clearance will be on top of the journal. No way to use Plastigage without taking the crank all the way out (unless I'm overlooking something).

The oil pump checks will be relatively easy to do > >

I have never plastigauged "upside down". Don't really know what the results would be. As you mentioned previously, you could hold the crank up. You could gauge the rod bearings. Start nearest the oil pump. I know of no way to install new mains with the engine in car. Rods you could do though.

First thing to try is an oil change with good oil. On a high miler Quad4 I'd use 10W40 or even 20W50 in the south. If you are in illinois, try 10W40.

I have had problems with some of the cheap "oilchanger" oils like Penzoil and the cheap ESSO stuff up here doing the same thing - get thin as kerosene when warm and loose all oilessure.

What brand of oil do you use? I've used Pennzoil exclusively for several years. Used to buy Kendall, but it's kind of scarce here in West Virginia these days.

Perhaps. I have heard of it being done. My current repair facility (for my own cars) is similar to yours except it is bit warmer out. Please let us know what you find. Paul.

No special tool needed. Small screwdriver, light tap with a hammer to get the bearing half started, then spin it out. The thrust bearing is a little tougher.

Steve

Apparently you have used that method and succeeded. That gives me some confidence.