96LT1Z

Just started noticing that my oil pressure is dropping at WOT.. It goes up steady to probably 70 not sure with the stock gauge, above 3k, then as the rpm keep going up, it drops to the middle mark on the gauge so 50? maybe? and then slowly goes up again from there.. Im really not happy about this, as I just replaced the oil pan 2 weeks ago... and if I need a new oil pump or something, im going to have to tear it out again.... Help!
More info,
5w-30 Valvoline syn power full synthetic
WIX Racing Oil Filter (short)
stock pan
believed to be stock oil pump (I never touched it)
Any help!!

Ed Wright

iTrader: (1)

Pour another quart in it. If that stops it, you may have a pick up problem.

96LT1Z

i already tried that... no what

devildog214

i also have the same problem at times, i do have a 160k motor so it does consume a bit, always checking on it but even topped off my pressure rarely goes past 50 or 60, and drops off at WOT most of the time, maybe to about 40.

96LT1Z

mines at 64k

leadfoot4

iTrader: (1)

IIRC, one of your earlier posts was about a dented oil pan. Assuming that you replaced the pan, A) was the pump's pick up tube oriented correctly; and B) are you POSITIVE that you didn't dislodge it during the pan swap?

Frequently, low oil pressure at WOT is caused by the pick up being out of kilter, and two things happen. The force of the car accelerating forward sends the oil to the rear of the pan, where it can't be reached by a pickup that's out of whack. Secondly, the increased engine speed is driving the pump at a higher rate, sucking up the oil faster, making the problem worse.

96LT1Z

Alright, yes i did just sway the pan because of the dent,
when i look at the pick up, the flat bottom of it was pretty much parrallel to the floor so it was level. Should it be different than that?
And no i am not positive i didnt hit it or somthing going back in. But if i still have good pressure when i start it and drive normal???
Another thing i noticed is if i right a gear up to about 3500 4K then WOT the pressure stays higher for a little longer and then doesnt drop all the way to the middle of the gauge, it stays a lil higher

englundjd

iirc there was a thread about this here on tech, it was prolly 6 months to a year ago. it was about a guy that was having this exact problem, at wide open throttle the oil pressure would dip and then come back up. my car does this to btw. I read in that thread that someone disassembled there engine because of it but did not find anything abnormal, no accelerated wear nothin.

Just an FYI my car has done it since I bought it, did it when it was stock at 115k miles and it does it now with a 355 that has 30k on it. iirc they did get the issue fixed but I dont remember what exactly they did

Ed Wright

iTrader: (1)

All that comes to my mind are:
1) pick up is too close to the bottom of the pan
2) engine has so much blow by that crank case pressure won't allow oil to return to the pan
3) some moron put a high volume pump in it, and too much oil is in the valve covers, and not in the pan
4) heavy weight oil used, which makes it return to the pan too slowly.

Adding a quart of oil should have effected numbers 2,3,&4.

WS Sick

Is the oil pressure sending unit oily?, the diaphram in it may have a small leak and it fudges it's numbers.
Dropping pressure falls usually in line right with what the others have said (in my experience.)

96LT1Z

so right now i have the oil level just above the full line, and have good pressure, when i start it cold it stays up around the 3/4 line and when i warms up it comes down to the 1/4 line and moves with the throttle.
And I keep checking it, its not going anywhere, the pick up surely is not too close to the pan, unless something happened to it, and i dont know how to tell if its a hv oil pump

96LT1Z

where is the oil pressure sensor??

93BlackZ28

iTrader: (5)

Behind the intake on the drivers side. Highly doubt it has a HV pump.

96LT1Z

I took a buddy of mine for a ride tonight to see what he thought of it, he noticed that first gear it dips a little bit but then 2nd and 3rd it went up and held steady and we did this a couple times and this is what happened. So I think its not big deal.. I think its probably just trying to catch up.. if it only dips down right when i get into it, and then comes up and stays there, i think im good?

96LT1Z

Its kinda like this not a big deal?
Also for all i know it could have been doing this ever since i got the car im not sure. Iv never looked at before at wot lol

leadfoot4

iTrader: (1)

I agree, at WOT, it's usually a good idea to be looking at the road!!


On a serious note, I don't see any issues there. The OP dips a little, but to me, it appears to be responding to the slight "let up" on the throttle as you shift gears....

wrd1972

iTrader: (12)

Mine does it too and here is the link to my old post with video:
https://ls1tech.com/forums/lt1-lt4-m...s-wot-wtf.html

It does it on the stock gauge and the mechanical gauge. I have checked pick-up height and nothing has resolved other to add some more oil which minimized it but did not totally cure it.

I have heard that the moroso windage tray IIRC, helps to resolve it. I have just decided to live with it and so far so good.

96LT1Z

thanks guys im just going to live with it i guess, i might fix if i do my clutch in a little while, pulling the trans would make pulling the pan a HELL of alot easier

robmnrd

I'm in the slight-drop at WOT club too. Build in sig, currently at ~190k miles on the bottom end.

Based on my experience and the research I've done online it doesn't seem to be something to worry about, especially if you've got good pressure under all other driving conditions.

bufmatmuslepants

iTrader: (3)

Mine does it too, always has.