I have a h.v. oil pump that puts out 80 p.s.i. I drove it to work a week ago and when i was going to lunch it had only 40 p.s.i. . I was 2 miles from work so i turned back. When i got back i had about 5-7 p.s.i . my oil is black and thin .I'm over due for an oil change.But i might need an oil pump.just want to get some advice.thanks

I would check the obvious first. Are you really low on oil?? What kind of guage do you have? Is it possible that the guage is bad? If you are not low on oil I would pull the dizzy and spin the oil pump shaft and check for oil coming up in the upper valve train. If you don't have oil up at the rockers I would than check to see if the pick up came off of the oil pump.

Oil Level Is Good.it's Just Black And Thin.

no metal at all in the oil?

no metal at all in the oil?
LAST NIGHT I DRAINED THE OIL AND TOOK THE FILTER OFF AND AT THE BOTTOM OF THE FILTER AFTER DRAINING SAY SOME VERY FINE METAL. IT WAS SO FINE YOU HAD TO SHINE THE FLASHLIGHT ON IT TO SEE THEM. LOOKED LIKE SILVERISH OIL.

i would check the valvetrain and see if a cam lobe is wearing off or something like that.

i would check the valvetrain and see if a cam lobe is wearing off or something like that.
I didn't want to change the oil pump, let alone pull the motor.

The MOTOR ONLY HAS ABOUT 8,000 MILES ON IT .

I didn't want to change the oil pump, let alone pull the motor.
Well, I don't mean to be an a$$... but you can be proactive and search out the answer.... or wait until it becomes obviously apparent.

The second choice is usually very expensive. I usually opt for the first option.... but I also sometimes enjoy destructive testing:crazy:

The clues are there.... you just gotta look for them, and sometimes that means turning over a few rocks along the way. Just think of all the personal knowledge you gain searching for the answer.... that is the priceless part of the equation.;)

The silverish oil in the bottom is pretty much normal. All motors wear to some degree... and that is reflected in the size of the chunks you find in the oil.

One method for checking lobe wear is to use a dial indicator to check advertised lobe profile numbers against what you record by measuring them with a dial indicator. Requires nothing more than removing the valve covers and measuring each lobes characteristics. I seriously doubt you are losing a lobe.

If you decide to measure the lobes.... also look for restrictions in the drain-back holes in the heads... IE particulate matter stopping-up the return path.

Only 2 miles down the road eh? Was the oil up to operating temp? What viscosity oil are you using? Thick (read cold) oil combined with a hi-volume pump may cause cavitation and low pressure 'til things stabilize thermally....


I am adding a subscription to your thread so I don't lose track of it... I do love solving puzzles...:D Also please keep in mind it is very difficult to diagnose issues by remote control, so try to be patient with the folks who chime in with helpful suggestions. Everyone's experience level is different, so you will get very wide ranging suggestions. Look at what you see in front of you, and choose to investigate the suggestion that makes the most sense to you. Most of the troubleshooting process is common sense based... cause and effect.

Good luck, and keep us up to date on what you find!

Well, I don't mean to be an a$$... but you can be proactive and search out the answer.... or wait until it becomes obviously apparent.

The second choice is usually very expensive. I usually opt for the first option.... but I also sometimes enjoy destructive testing:crazy:

The clues are there.... you just gotta look for them, and sometimes that means turning over a few rocks along the way. Just think of all the personal knowledge you gain searching for the answer.... that is the priceless part of the equation.;)

The silverish oil in the bottom is pretty much normal. All motors wear to some degree... and that is reflected in the size of the chunks you find in the oil.

One method for checking lobe wear is to use a dial indicator to check advertised lobe profile numbers against what you record by measuring them with a dial indicator. Requires nothing more than removing the valve covers and measuring each lobes characteristics. I seriously doubt you are losing a lobe.

If you decide to measure the lobes.... also look for restrictions in the drain-back holes in the heads... IE particulate matter stopping-up the return path.

Only 2 miles down the road eh? Was the oil up to operating temp? What viscosity oil are you using? Thick (read cold) oil combined with a hi-volume pump may cause cavitation and low pressure 'til things stabilize thermally....


I am adding a subscription to your thread so I don't lose track of it... I do love solving puzzles...:D Also please keep in mind it is very difficult to diagnose issues by remote control, so try to be patient with the folks who chime in with helpful suggestions. Everyone's experience level is different, so you will get very wide ranging suggestions. Look at what you see in front of you, and choose to investigate the suggestion that makes the most sense to you. Most of the troubleshooting process is common sense based... cause and effect.

Good luck, and keep us up to date on what you find!
Thanks for all the advice,when i get home i'm going to see if going to a 20-50w will make a differance.If not i'll change the pump.

i had my engine do the same thing at 3000 miles. ended up valve spring dampners broke wedged into the springs and nicked the cam and cause lobes to wear down. in the end, the metal from the cam causes the bearings to go out and my oil pressure dropped to about 7psi at idle and about 35 on the road.

u mite want to read this.
http://www.nastyz28.com/forum/showthread.php?t=65870

Last night changed oil to 20/50w and drove it about 2 miles oil pressure didn't go below 60 psi.But it sounds like i need to adjust my lifters.

But it sounds like i need to adjust my lifters.

Is this a hydraulic cam or a solid cam? If you're hearing unusual noise that you didn't hear before, then I'd investigate a little further. Noisy valve trains usually are caused by: Aggressive lobe designs, oil starvation in the top end, or solid cams. If you have a hydraulic cam, you should not need to readjust the valves and I'd suspect a lobe is on it's way out.

+1 Golden also check for broken valve springs or dampners and cracked or broken rocker arms or bent pushrods. Good Luck:bowtie:

Last night changed oil to 20/50w and drove it about 2 miles oil pressure didn't go below 60 psi.But it sounds like i need to adjust my lifters.
Did the old oil smell like fuel? If so, you are prolly in process of wiping the cam. Check valve lift with a dial indicator would be my next step.... after checking for obvious signs of breakage.