Usually runs 50lbs.+ but dropped to near 10lbs. this morning with the light coming on at idle. Before I hit the panic button I'd like to hear what some of you folks have to say.
When these pumps fail do they sometimes provide minimal pressure? I had a 302 that failed on me twice and provided none at all (like shutting off the light switch)
This IS my worktruck and only 4 wheeled transportation so when I "make a move" I have to be "quick & concise".
I hope nobody minds, but I'm going to post this question on the '67&up board also (It seems to have more traffic)
Help Guys !........I need answers....Quick !

 

Hey 66...before we go too much farther, you should get a fully mechanical guage to check your oil pressure. remove your sending unit, connect the guage and see what you have.
You will know right away if you really have oil pressure or not.
Wayne

 

Being a "camper special" it has both sending units.
I just came back from the garage where I removed & cleaned BOTH sending units AND tried each one independently. I also changed the oil filter (for posterity).
Same results. The light goes out at approx. 10lbs. (about 10 seconds to build this much pressure) and the gauge builds to about 15-20 lbs. BUT I'm losing all pressure at stoplights.

 

I have to ask...how old is the engine oil? and is the oil level where it should be? I will go to the chat room on this site..

Wayne

 

I am thinking the oil pump may need to be replaced. Is there an oil leak under pressure? how many miles on your mill?

Wayne

 

66work, what oil are you running? 10-30 was scary in my truck before the new engine. I switched to straight 70 wt pennzoil aircraft oil and turned the idle up to about 850. This got me from 0 at idle to 15 pounds. Ran for a year that way. It finally was retired after a popped head gasket. I would run the thick oil and hi idle while waiting for a mellings M57HV oil pump. You'll have to drop the pan, but while your getting messy it gives you a good oppourtunity to remove the filter adapter as well and drill out the oil passages. If you already have the big pump it is probably time for new bearings. DF

 

This is a "leakfree","smokefree","noisefree" 123,000 mile engine. It receives oil changes at 2k intervals. 10w40 (winter)
20w50 (summer). I am very "aware" of my gauges AND this whole episode occured over a 3 mile area this morning.....(nothing gradual about this deal). I'm beginning to think that something has parked itself over the sump screen. (at least partially)

 

Hey 66, it sounds like tie to pull that oil pan and see what you got there. I have run across an oil pickup tube came loose from the oil pump casting. This is a rare occurance but it could happen anyway. I wish you well sir..

Wayne

 

I'll take a stab at this one. I have dual senders on mine, the light and gauge. When your pressure drops, does the light come on? If not, I would recommend replacing the gauge bee hive type sender. These are available over the counter at any chain type parts store. There is a diaphram inside these that maybe giving out after a short time. My old one actually seeped oil at the top terminal. You know your oil gauge is working, and if the fuel & temp gauges are normal and your oil gauge is factory, the voltage regulator in the dash is probally ok. Try this cheap fix first, might save alot of work later. Worst case would be a worn engine that isn't holding pressure due to worn internal parts, especially when the oil is warm and the truck is idling.. Good Luck.....

 

I would mark and then remove the dist. Get a oil pump primer or make one from junk dist. run the oil pump with a drill and remove the valve covers. Check the pressure and oil flow. Remove the oil pan and check for blockage and loose pickup tube. Remove the oil filter adapter and look for blockage / broken gasket...

A rod bolt might have given up or a bearing spun just enough to cause problem but not enough to cause noise. If you wanted to, you could use one of those engine oil flush solutions and see if you can clean it out then change oil and filter.

I'm not sure, but can't the bypass valve be stuck open? I think they are spring loaded valves and it may have gotton clogged up and stuck open causing the oil to bypass the system and return to the pan.

Most likely a clogged screen, let us know what happens.

 

Must have been SOME TYPE of "obstruction".
I ran out to the grocery store earlier this evening (ol'lady forgot the white wine) and as I was pulling into the parking lot the gauge SHOT UP to 50lbs. Has not gone below 45 since.
Tomorrow is another day. I'll keep y'all informed.
Thanks everyone.

 

I wonder if something had blocked the oil pressure relief valve, because it would be before the filter and so a big particle could in theory hold it open then later be knocked loose with enough oil flushing it out.