i took my car out for a cruise last night and i decided to put the pedal to the metal.went through each gear to 5800 rpms.well at 120 miles per hour in fourth gear i noticed my oil pressure dropped to around 15 psi.as soon as i got the speed and rpms down it went back up to 50 psi.i do have a high volume oil pump.is it possible that all of the oil was at the top side of the engine.by the way my oil pressure sensor is at the oil filter...dont know if that has anything to do with it anyway.also i checked the oil and it was a half a quart low.anyone else ever experience this?

 

Could be a drain back issue or a windage problem. There may be something stopping the oil from draining into the pan from the heads and/or lifter valley. Also, at high RPM the crank will slap the oil around suspending it in the crankcase. That'll prevent it from being able to be picked up by the oil pump.

What's the pickup height? If it's too low it will restrict the amount of oil into the pump. Or if it's too high it will suck air.

 

i have no idea what the pickup height.i believe we installed it up until the little ridge on the pickup tube stopped it from going any farther.ive been thinking about a high volume oil pan.would this help.would it even fit on my thirdgen?

 

The height is how high the pickup screen is from the bottom of the pan, not how far in the housing the pickup is pressed. Any time you put on a new pump or pickup you need to measure the pickup height to avoid any problems.

 

i see said the blind man.sorry.i got confused there.well any suggestions about the bigger pan.i can check the height when i install the pan.

 

It could be possible that the high volume pump is sucking the pan dry in which case a higher volume pan may help. I would check out the basics first.

 

this is a fairly comon problem, and theres two fairly comon causes
(1) if youve got a stock 4-5 qt oil pan with no windage tray or baffling your working at a distinct dis-addvantage, as the volume of oil and the return flow plus the crank wipping the oil into a froth all work against you.

(2)the oil pan pick-up MUST be located no closer than 3/8" and no further than 1/2" off the pan floor to both stay covered and allow a constant flow

the ideal way to handle this is to install a baffled oil pan with a 7-8 qt capacity and with a matching windage screen and high volume oil pump

http://www.moroso.com/catalog/catego...?catcode=11330

 

thanks for the information.

since i dont race the car and only occasionally go that fast is this issue i need to correct?also will the bigger oil pan fit without having to modify exhaust or anything else?

 

"will the bigger oil pan fit without having to modify exhaust or anything else?"

youll need to ask each manufacturer pointed questions, and detailed questions about that, in most cases an oil pan thats designed for your application will work just fine with MOST aftermarket accessories, generic pans may cause a problem.


http://www.stefs.com/stefsindex.htm

http://www.kevko.net/

http://moroso.com/default.asp

http://www.cantonracingproducts.com/

http://www.milodon.net/

http://www.midwestmotorsportsinc.com..._sub.php?id=33

btw youll generally want no deeper than 7.5" MAX AND NO LESS THAN 7 QTS

 

is it normal for the oil guage/needle to jump a little back and forth when pressing on the gas pedal or reving it up?

 

yes because the faster the rpm's the more it will pump.the slower the rpm's the less it will pump.

 

before ya tear it down try replacing the oil filter.
Wouldn't be the first time....

 

You're sucking the pan dry of oil. Options are

Don't use a high volume oil pump for high rpm operation.
Get the oil back into the pan as quickly as possible by removing any lifter valley screens or installing course mesh screens that will allow oil to quickly flow through them but still strap large metal parts.
Using of an oil accumulator will help when oil pressure drops.
Install a higher capacity oil pan.

 

yea that makes sense,but i changed oil and filter a week ago.

 

I've got a stock pan on my car and a high volume pump. It traps 120mph and 6200 RPM with no oil issues. Setup properly you should have no probelms. Your issue is probably due to inadequate drainback or an improperly installed pickup (height).

The relief valve in the pump and in the oil filter adapter may be bypassing too much oil. On most modified engines I tap and plug the relief valve in the housing adapter.

 

Are you saying that you changed the oil and filter and now suddenly you have a problem. Or you've has a problem, changed the oil and filter and still have a problem.

i recently has the same problem. Changed the oil filter and the problem dissappeared. It was a faulty oil filter.

Up until that point never had a problem with oil pressure at high rpm, on any of my motors.

 

i never went that fast before the oil change.it was the break in oil.changed oil and filter and it was time for a road test.

 

Break in oil, meaning it's a new motor? That opens up a new can of worms.

 

rebuilt motor.