Is my oil pressure OK?

[Joe Flanagan]

I get 20 at idle. But when I rev the engine, it stays at 20. Fluctuates a little around the 20 mark but doesn't go beyond it. I checked an old thread that indicates 20 is OK at idle but you should be up to 40 or so while going at 30 MPH. Shouldn't my pressure spike when I rev the engine?

[jd52cranbrook]

20 at higher rpm is not good. Could be several things, but I would but a secondary pressure gauge and put it on one several oil outlets on the side of the block to be sure yours is working. But I would not run the car until you find out.

[aero3113]

It won't spike it, should go up to around 40 when you rev. It sounds like your gauge might not go past 20 for some reason. Maybe you can take it apart, clean and lube it. In my manual it says anything above 0 at idle is is good. Did you ever get around to installing the pressure gauge on the engine that Don suggested? What is the pressure when you first start it? That is when the pressure will be the highest because the oil is still thick.

[aero3113]

Also check your pressure valve spring it might be weak and needs to be replaced.The valve may be stuck also not allowing it to adjust oil pressure properly.

[David Strieb]

seems a little low. My p10 engine had 10lbs at idle, 25 while driving. Ran great, no noise. My chrysler and dodge both run 20 at idle and 35 driving. There are different pressure springs you can use, they vary in color. They're located behind a hex head nut by the oil dipstick, You may want to try another pressure gauge, just hook it up in the engine bay real quick to see what it reads for comparison before you do anything major. Maybe a new oil pump??

[Joe Flanagan]

I am currently using a pressure gauge I got at Lowe's that is connected directly into the block like Don C. did. The oil pump is rebuilt with all new parts. When I first start the engine it goes to 20. When I rev it, the needle wavers between 20 and 25.

The oil pressure relief valve, as I understand it, does not come into play until the pressure gets high enough, at which point it opens and allows oil to return to the block from the oil filter canister.

[aero3113]

The valve can be stuck in the open position not allowing the engine to build up pressure. What does the gauge read in the car when running?

[jd52cranbrook]

But even with the valve stuck and all oil is going through the filter the pressure should be much higher. Its just that, pressure, ones the circuit, or fluid reaches everywhere it's going to go, the pressure is still pushing. Unless the oil is leaving the block somewhere new, something is wrong.

[jd52cranbrook]

You might try another gauge, or test that one with a air line briefly.

[jd52cranbrook]

My mistake, with the valve open it would allow oil back into the crankcase. Sorry.

[Joe Flanagan]

Here is how I have the gauge hooked up right now. Would the use of the rubber hose be giving me an inaccurate reading for any reason?

Checking the relief valve right now and though it is in correctly it seems to be stuck in place. Should you be able to remove it with your fingers?

[aero3113]

In my manual it says if you have low oil pressure check these things:

External leaks - Inspect for possible leakage.Wipe the oil lines and fittings clean,run the engine at fast idle and look for traces of oil at the points cleaned.

Oil pressure relief valve - Inspect for a broken spring or distorted oil pressure relief valve spring. Check plunger for dirt,nicks or burrs.

Oil pressure gauge - Inspect the oil pressure gauge for accuracy,by connecting an accurate gauge in line with a "T" fitting.

Oil - Make certain that oil of the recommended weight is used in the crankcase.

Excessive bearing clearance- Check the flow of oil at the bearings by using a bearing leak detector.

Oil pump - Inspect the oil pump parts for excessive clearance.

Edited March 6, 2010 by aero3113

[aero3113]

You should be able to get a magnet and it should slide right out.I think when I removed mine to inspect it was stuck to the spring and it slid right out. I have also heard of people cranking the engine quick and it will pop out. Put a rag over it so it will not shoot out and bounce around the garage.

Make sure it was and is installed the correct way.

[Joe Flanagan]

The spring and the plug came right out. The plunger appears to be stuck in there but it was installed correctly. Trying to get it out now. I'm using 10W40 oil. I'm going to see if I can free up the plug and see what happens then.

[Joe Flanagan]

Tried cranking and it wouldn't come out. I also tried a long drywall screw but it won't tap into the hole at the end of the plunger. I'll have to try a screw with a self-tapping thread. I saw a discussion of this problem in the archives where someone used a #5 easy out to get the plunger out. I have a #5 but it's way too skinny to do the job.

[aero3113]

once you get it out clean it up with some scotch brite and try and get in the hole also.

[aero3113]

Are you sure there is a plunger in there? Could the hole you see be the back of the block?

[Joe Flanagan]

No, the plunger is there.

[40phil41]

Tried cranking and it wouldn't come out. I also tried a long drywall screw but it won't tap into the hole at the end of the plunger. I'll have to try a screw with a self-tapping thread. I saw a discussion of this problem in the archives where someone used a #5 easy out to get the plunger out. I have a #5 but it's way too skinny to do the job.

Here is what I used; an easy-out. Worked beautifully. My spring was broken (3 pieces) and the plunger was very stuck. In my case the oil pressure was excessively high.

Phil

[randroid]

Folks,

In my VW manual it suggests using a brake hone to ream the nole, making sure to get the hole clean after using the hone. I did it and it works flawlessly. On Pigiron I used an auxiliary gauge and found that the oil pressure was actually low with a new oil pump, so I dropped the pan, replaced the gasket and added an o-ring to the pick-up tube to keep it from sucking air. I can't tell you which one did the trick but the oil pressure has been normal since.

-Randy

[Joe Flanagan]

I got the plunger out using a sheet metal screw. Went over it with fine sandpaper and did the same to the bore of the hole. Wiped everything clean and am ready to reinstall. One question though. I have the green spring, which is for high oil pressure. It's the one that was sent with the new valve when I rebuilt the engine. If I still have the original, should I go back with that?

[aero3113]

Im not sure which you should use but you can try out both and see what one gives you the correct pressure.

[Don Coatney]

Joe;

It has been 7-8 years so I dont remember. Did you plastigauge your crankshaft bearings?

[JIPJOBXX]

Hay it can't hurt to try the old spring! I would if it were me.

[Joe Flanagan]

I solved the problem. It was the relief valve. I removed it, cleaned it up, reinstalled it with the old spring and started the engine. The oil pressure shot up to 40+ immediately. That was a big relief.

I was also able to get it to stay running. I don't know how, but now it just keeps running all by itself. I ran it for about a half an hour at high idle for its break in period. At a certain point, it quit. This was with about five minutes left for the break in. I started it again but it seemed very sluggish, like it had difficulty turning over. That lasted only a second and then it fired up. I've started it a few times since and it starts fine.

I then re-torqued all the head bolts. Everything seems OK.

I do have some leaks: The major one is from the water pump impeller shaft. Lots of coolant coming out there. It hits the fan and makes a hell of a mess. I also have a slow drip coming from the cover of the oil pump. There were a couple of loose bolts that I tightened but it still drips.

There is also an exhaust leak from around the manifold. I don't know if it's just my imagination, but it seemed to improve as the engine ran.

Temp stayed steady at about 170-180. My used temp gauge works!

To answer Don C.'s question, yes, I did plastigauge all the bearings.

So tomorrow I plan to start it again, just for peace of mind. Then I'm going to change the oil. Then I need to remove the water pump and see what's going on there.

On another note, you wouldn't believe the stuff that came out of the exhaust pipe. Looks like a combination between rust and soot. And lots of it.

Also, I just checked the oil and it looks like it is low a quart. I put five in and it was up to the full line. As I said, there is a drip at the oil pump cover and I had quite a lot coming out from the filter lid at one point, so I'm going to have to assume that's where it went. Unless I've got a quart sitting in the filter canister.