odd oil pressure readings..
 

this is from the gauge in the factory cluster so perhaps its wrong.. but what I've been noticing seems strange to me. idling is always around 45-50 psi cold or hot, accelerating gets it up to 60 for mild, and full throttle can bring it up to 80. Here is the odd part... in first and second gear at WOT the psi drops to just under the 40 mark in the upper RPMs, as soon as I shift it returns to normal and back down if it's the 1-2 shift, all other gears pressure reads normal and around 70 WOT pulling to redline. Any ideas or is my gauge just being wacky?

oil pump
 

it sounds like 2 things to me for 1 are stock guages are inaccurate and read diffrently especially if you are in the heat like this 120 degree vegas heat but it shouldent be that much of a diffrence of 20 psi .for 2 have u swiched out your oil pump to a ported and blueprinted one( if its surging down with u in the upper rpm i would switch it out asap before u get a KABOOM! these oil pumps are notirous for going out all of a sudden ?? they arent hard to install located directly ontop of your oil filter:secret2:

I bought the car used, so perhaps the pump has been replaced. Not while I've had the vehicle, though, it has done this from day one. Just finally got around to asking. It only does this in first and second gear is the odd thing. Could a vacuum issue be causing the oil pressure gauge to read off like that? Like I said, as soon as the load comes off and the clutch pedal is in ( read : RPMS still high ) it will jump back up to around 60 on the gauge.

well i would have everything checked out first but to me its worth the $$$ to replace your pump with a melling unit. the stock ls1 pump is pretty much garbage.

If you are replacing, make sure you purchase a HIGH PRESSURE PUMP and not high volume.

Oil pump is located on the front of the crank behind the timing cover.

last time i changed a ls1 oil pump it was on the front and last time i did the oil change on one the filter was under the car and towred the back of the oil pan which ls1 have you been touching?

yeah i was wondering what he meant by that. i just figured it was some sort of typo...

So... which part # is it for the high pressure unit??? I'm about due for a new oil pump for the rebuild.

just a typo / its behind the timing cover other than that go like others sayed above "melling unit a couple of the sponsors here sell them and they can get it to you at a reduced price / the ls1tech discount plus some offer free shipping ontop of the ls1tech discount

try adding 1/2 qt of oil and see if it still drops off in 1st and 2nd...might be starving for oil under high accelleration.

I'll look into a pump and ask around a bit. as for perhaps adding more oil, how much is the LS1 suppose to hold at oil change time? 5qts has always taken care of covering the dipstick to the correct area for me..

As for the melling pump, does anyone recommend a certain sponsor? or a certain part number? First two I found were stock replacement and high volume.. no high pressure pumps.

WHAT ?? its 5.5 quarts its possable your oil pump is trying so hard push oil through that its failing at high rpm's

Melling 10296 is part #. It is the high volume pump. The 10295 is OEM spec.

And you can safely run 6qts. in these cars. I do it every oil change. It helps keep the pickup submerged during hard cornering......

I run 6.5 quarts in mine, and it stopped the pressure drop I see in first and second. Also I think it has to do with how hot your oil is, and also how old/broke down it is.

wow.. didn't know the LS1 held that much more than the LT1! I'll run 6qts from now on. Thanks guys! hopefully it didn't hurt the oil pump any. I would imagine 40psi was plenty for the engine though. Love when it's those simple things right? haha. but.. :bang: stupid on my end

well while were on this topic for future reference, whats the difference between high pressure and high volume oil pumps?

mine has done that once before, for about a week. Turned out to be a clogged Fram :bang: I switched to Napa Gold and never looked back.

mine's never done that and i've had fram before..... but i'm pretty anal about oil changes, maybe I got lucky?

Did an oil change last weekend on the car, and bought an extra qaurt. Filled the car up with the 5qts... and just as I thought, it was full. How are you guys getting 6qts in? It may just be using some and causing what you all were describing. Oil pressure was fine after the oil change, So I'll just keep a closer eye on it between changes now. Thanks everyone!

Anyone who thinks they are smarter then a dipstick is well....pretty damn stupid. You did the right thing by not forcing the last quart in. :cheers: