i have a motor that gets 65 psi of oil pressure at start up and after about 10 min of fully warm/driving around im lucky if i get liek 10 psi at idle, how do i tell if the bearings are shot or the oil pump is bad? thanks

Joe

 

You forgot a few other possibilities:

• The oil drainbascks could be sludged and not allowing good return, hence, teh pump would suck some air with the oil;
• The pressure transducer could be fornicated;
• The pump relief valve could be sludged and sticking open (leaking internally);
• The pump pickup could be sludged and fighting to draw oil through;
• The PCV system is not working, allowing moisture formation in the oil;
• The pump pickup could be loose (sucking air);
• You might be using an inferior oil;

You may see a common problem - sludge - in some of those possibilities.

What oil type and viscosity are you using? Filter? Howe frequently do you change it? What is the oil's appearance?

 

recently rebuilt motor within the last year and a half, the oil gets changed about every 6 months regardless of miles, its never seen over 500 miles on oil. i use castrol gtx 10w40 and the HV pump and all associated parts were all new. the onlything thats used is the block and crank, which were machined by a reputable shop. the PCV is working, and hte oil looks liek the normal blackish color when you drain it and theres only a few little powdery pieces of metal on the drain plugs, not chunks, but the very very fine normal wear stuff. if my rod or main bearings were getting worn/out of tolerance wouldnt the motor be making some sort of noise?


joe

 

i listened to the car with a automotoive stethoscope and i hear no abnormal noises in the motor i went all over the engine from top to bottom and nothing sounds out of whack. im gonna try changing the oiil and seeing if that helps maybe the oil is degraded after 3 runs at the strip i dont know?


joe

 

Are you monitoring oil pressure with the dash gauge or an independent test gauge? You should verify the dash "instrument" with a separate mechanical gauge to be sure it is close to correct calibration.