Heres my problem.

Going down the road i have great oil pressure right abour 60psi. Varies with throttle opening and closing. But at idle it goes down to about 10 or lower, i know this is not right, But what could it be. Thanks for all the help.

 

Do you think its accurate or your gauge is misreading?

 

what does the motor sound like when it is hot and idling?

do you hear your valvetrain

 

When its hot its sounds great you hear the lope on the cam and exshaust but thats about it. I am pretty sure the gauge is accurate its only about 6months old and its a after market auto meter. I also installed the sending unit the sent with the gauge.

 

You might want to buy a cheap mechanical gauge to double check your low oil pressure reading. Its probably not the guage but to me its worth it to spend a few bucks to double check it before going through the hassle of pulling a motor. If the oil pressure is definately that low then you have a problem. Oil pressure that low at idle usually means you have excessive bearing clearance from lots of wear or you spun a bearing. If its just wear(not a spun bearing) and you don't hear any knocking sound then you can probably keep driving it for awhile as long as you don't abuse it too bad...not suggested but you might be able to get away with it for awhile if you have to drive it. I would change the oil and look for metal..look at the oil and then cut open the filter and look inside. If theres a lot of metal, you might as well park it and pull the motor.

 

If it comes down to it and its a matter of low oil pressure after checkin with a new gauge, What woudl you recommend doin. I know i have to yank the motor, but Is the only possible answer the excessive bearing clearance, on the crank and rods, or a spun bearing. Is there ANYTHIGN else it could be?

 

Unfortunately, bearings are about it. how many miles are on the engine?

 

approx 5,000

 

5000miles then it must be rebuilt or
newly assembled?

I read before a guy on same kinda situation,
his problem was something was done wrong when he was putting his motor in(this guy's motor was newly swapped also i believe)

so if u have 5000miles on it and u rebuilt it urself.
suckingly u might have done something wrong..


try a little thicker grade oil though
and see if it might help a bit,
i run a 20-50 in my engine becaz with a 5-30 my psi in hot idle
goes lower than 15 where with 20-50(+additive) gives me
higher reading like 25-30.

but my engine is at its 190K.. so yeah.. good luck!

 

I'd say theres about a 99% chance you have a bearing problem. Oil pumps rarely go bad. The only other thing that occasionally happens if if your oil pickup falls off the pump but it doesn't sound like you have that problem since your oil pressure does go up some while driving.

 

mine starts out okay when cold but eventually goes down. when it's warm and at a red light idling it reads just a little above the redline (low side) is that normal when it's warm and idling or is that a sign my engine will be boom soon

 

Rule of thumb is 10 psi / 1000 RPM.

There are countless people running for years on the pressure you describe.

 

That's what i thought. I had an el camino that ran low according to people but i used that rule of thumb and it ran flawlessly over 131K. (then my torque converter broke, kept holding off on the controller for other parts) It still runs great today!

Hey thanks!

 

ok similar problem, motor from what i can tell fromm all repair history only has about 115000 mi on it, being 3rd owner i cant know for sure, i know that once i removed the ring from bottom of air cleaner, rpm's went up a bit to red or past, but no apparent problem. but after recent oil change and going to lighter oil motor has going lower in pressure, everything is orig. it's a 92 so these kinds of random problems should'nt be here yet. car has not been raced in my possesion. oil reading is almost red at idle but at 15 or so driving.(bad) should i just go to full syn oil first or do compression chk or what? it's a 305 tbi so going bigger would'nt be an unhappy plausible. but on beer budget champaign don't do so good. 2nd kid due in 3 weeks. h e l p.

 

what weight of oil are you running in your car? try 20w50 it should raise your pressure up considerably