[HWYSTR455]

What kind of filter are you using? Try first changing the filter. Wix or PF24. K&Ns clog fast. Internals can collapse too, especially during the first few cold runs in the winter.

.

[moneypit]

Well I dissected the oil filter and found nothing unusual. I will hook up another gauge this evening. I do use a manual gauge and a copper line.

[Nicks67GTO]

Ive had an autometer gauge that sat for a long time get weird on me a few years back. I verified the oil pressure with a different gauge, ran some oil up in the oil pressure line, rehooked it up to the autometer gauge and all was well.

Ive also had a main bearing go out in a 400 Pontiac that is acting exactly like you are describing. It only had a few thousand miles on it and my idle oil pressure dropped out of the sky to around 5 lbs but was still responding to throttle well. all at once it locked up hard, spun a main bearing and that was it. I would verify the gauge. If its good, I would pull the engnie and check it. Better to be safe than sorry here.

[PontGuy]

Have you tried starting it up again now that it has sat for a bit? Really hoping that it is just a stuck ball and the thick cold oil breaks it free. If the gauge reading is confirmed good and pressure is still low then next step is to pull the engine and open it up.

No metal in the oil filter is a good sign. First time this happened to me it was just a pump problem. So it still may not be that big a deal although having to pull the engine to resolve an issue is never fun.

[HWYSTR455]

Originally Posted by moneypit

Well I dissected the oil filter and found nothing unusual. I will hook up another gauge this evening. I do use a manual gauge and a copper line.

Still curious as to what brand oil filter you had on there?

Sure you checked, but figure I'd ask, no kinks in the copper line?

.

[lfdsteve]

Slightly off topic but how do you cut open filter then discern what is in the filter vs shavings from cutting?
Steve

[HWYSTR455]

Originally Posted by lfdsteve

Slightly off topic but how do you cut open filter then discern what is in the filter vs shavings from cutting?
Steve

Cut, don't saw. Use a cutter. Or a utility knife.

.

[mrennie]

Originally Posted by lfdsteve

Slightly off topic but how do you cut open filter then discern what is in the filter vs shavings from cutting?
Steve

Summit Racing sells a very nice filter cutter, not exactly cheap, but does a great job. It is like a giant pipe cutter with a sharp cutting wheel and takes the top off a filter in about 4 to 5 turns.

Seems pricy at first but once you have if you will be looking inside the filters off all the engines you maintain.

[moneypit]

Originally Posted by HWYSTR455

Still curious as to what brand oil filter you had on there?

Sure you checked, but figure I'd ask, no kinks in the copper line?

.

Wix 51258
haven't done the gauge yet, will post results as soon as I do.

[HWYSTR455]

Originally Posted by moneypit

Wix 51258
haven't done the gauge yet, will post results as soon as I do.

Nice. That's ruled out then, don't think those have a tendancy to collapse or clog.

.

[East]

http://forums.maxperformanceinc.com/...d.php?t=739131

As much as was in denial about a new oild pump, it turns out that the oil pump was the problem.

Whether it was the clearances or whether it was the check ball, it was still the [new]oil pump.


My pressure has returned to 35-40+ psi at idle on the road with engine running 180+ degrees temperature and 60+ on cold startup/at speed limit.

Many posts with information pertaining to this problem.

-----Kevin

[moneypit]

Originally Posted by East

http://forums.maxperformanceinc.com/...d.php?t=739131

As much as was in denial about a new oild pump, it turns out that the oil pump was the problem.

Whether it was the clearances or whether it was the check ball, it was still the [new]oil pump.


My pressure has returned to 35-40+ psi at idle on the road with engine running 180+ degrees temperature and 60+ on cold startup/at speed limit.

Many posts with information pertaining to this problem.

-----Kevin

Thanks For the link.

Well I tried a different gauge with the same results. Yesterday I pulled the engine and that took the whole day! ( I'm old and slow) The good news is the pan is very clean, no trash or metal to be found. I haven't taken apart the oil pump yet. I was using a Melling M54F
pump. I don't know about trying to "fix" the one I have or just shelling out the $$ for a new BPI-M54-PRO from Butler. I will let you know what I find in the pump if anything.

Colt.

[East]

Were you able to get to the pump yet? The pump that you speak of is the same as what is in most of the posts that relate to the problem that you reported.

I ended up putting the old pump back in even though I had purchased an exact replacement. I wanted to put it back in after I took it apart to look for debris in the check ball area and under the plate clearances but I knew the old one was working before I took it out. I was also on the THIRD round of removing engine and I was stressed for time because I had to register the car and move out of our house.

I suppose that one must double check all parts regardless of them being new and fresh out of the box. Darn shame but standard procedures for those in the PY forums that are in-the know and wise when it comes to their engines.

You will be relieved when all is said and done; I was.

-----Kevin

[geeteeohguy]

Funny how 40 year old, used, made in USA parts are far superior to brand new parts. Makes me very leery of pretty much any 'new' part.

[East]

I was very happy that the new oil pump costs less than $40 from NAPA and was the same pump and readily available. The bad part was that I could not just install it and think nothing of it as I did the old one that was installed in the early 1990s.

I am also thinking of all the original parts on my Firebird that are still working after forty years where the electric window button on my 1993 GMC Safari has been replaced three times at over $60 a pop. I just replaced it with an original GMC part and it still hasn't reached a year old and is failing. It won't be long before the button falls off and all of the parts behind it fly out.

We just moved to a smaller home to cut costs and we have to reduce our amount of stuff. I am seeing that most of the older kitchen devices are still around but the newer things we bought are broken in some way.

Getting back to the oil pump and auto parts, I will never take it for granted to check whatever I can so that I don't have to go through the same ordeal again.

I was glad to find the answer to my problem by searching the forum but was hard set not to have to do all of the work. It was impressive that a lot of people in here can diagnose sight unseen and be right on the money with the solution.

I have to admit that after removing the engine three times in a row, I have regained my efficiency in the amount of time it takes for that task. I didn't even have to sort the bolts/fasteners as I recognized the locations for all of them.

One more good thing is that my registration expiration has moved back a month to October where the temperatures are much cooler for smog testing and tune-up.

-----Kevin

[PontGuy]

Are you sure that a defective pump is the problem? No doubt its possible (Kevin's experience) but if the pressure was fine and then suddenly dropped then something has changed.

I mentioned before that I had a sudden drop in pressure because of pump damage. What happened to me is that a piece of shot from the shake and bake got into the pump and galled the lower plate. Its also possible for the bypass ball to get stuck as mentioned many times.

Suggest that you disassemble and inspect the pump. If there are no obvious signs of problems then check the bearings, etc. while you have the engine open.

[moneypit]

Nothing in the filter.
Nothing in the pan.
Something definitely has passed through the oil pump, inside of housing scarred up, one gear has a couple small chips. The seat that the check ball rides on appears pitted like something was hammering on it. I guess I'm going to have to completely tear down my engine to try and find the culprit.

[PontGuy]

If you have a chipped tooth and scarring in the pump housing at least you now know the reason for the pressure loss. And anything that goes through the pump would return to the pan through the bypass or get picked up by the filter. But agree that it would be best to confirm exactly what happened and make sure there is no loose metal in the engine. Since your situation now sounds a lot like my experience here is a link to the thread that tells my story from beginning to end. Includes pics of the pump damage and the steel shot that caused it.

http://forums.maxperformanceinc.com/...=635510&page=2

Can you post pics of your pump?

[moneypit]

I will try and post some pics tonight if I have time. I won't be able to get anything done before T-Day. With any luck I hope to have it torn down, inspected and reassembled before X-mas.
Thanks for all the suggestions!
Colt.

[moneypit]

Here are some pics of the oil pump. I found nothing in the filter or the pan