96blackta

iTrader: (7)

I have a 1996 LT1...

On a cold start my oil pressure is normal (40 psi). After the engine warms up and I've been driving a bit, my oil pressure plummets at idle (5-20 psi). When I begin driving again, it shoots back up (35-40 psi). I'm running 10w30 Royal Purple synthetic. I have no idea what the first owner ran in it. The car was also purely stock when I bought it. So far I've only modded the intake with a K&N cold air kit. My friend who knows a lot about F-bodies and engines in general doesn't think it's the bearings, because he listened to the engine and said everything sounds normal... no knocking/pinging/etc. Could the issue be an oil pump? Would it be so consistent with the cold start-normal psi, warm engine-low psi if it was the pump?

Formula350

iTrader: (3)

Welcome to the world of the LT1. You are with in the MANUALS specs of 10-15psi at idle

96blackta

iTrader: (7)

What if the "check gauges" light actually came on once or twice from it?

grossesexy

Does it drop right off when you shut the car off or does it hold pressure?

Formula350

iTrader: (3)

o_0 OIL pressure, not fuel pressure heh How would the oil hold pressure when the motor isn't running anymore?

grossesexy

Haha, man I'm out of it.

Yea, like you said before that's totally normal for oil pressure.

iceman15

iTrader: (10)

You can also change your oil pressure sending unit, it might be giving a somewhat false reading. But either way 10-15psi is normal for idle

96blackta

iTrader: (7)

lol, that's what I get for having friends with LS1s. Dude, your oil pressure is way too low!

Mattsz28

iTrader: (1)

My stocker did the same thing from the time I got it to the time I pulled it. 11psi Hot idle on a mech gauge. Nothing to worry about. 10psi per 1k rpm. As long as you on that your good to go. If it keeps kicking the light just get a mech gauge and run it into the cabin. If you pull the plug on the pressure gauge the light doesnt kick.

96blackta

iTrader: (7)

With the oil pressure plummeting and the temp raising at the same time, I got a little scared. But I guess all cars heat up when they sit at idle, lol.

Has anyone installed a high volume pump and seen gains in their idle pressure?

And where can I find this specific gauge?

Mattsz28

iTrader: (1)

Any mechanical gauge that is for Oil PSI will do just fun. You install it were the sensor is located now (behind the intake under the cowl, closer to the drivers side.) I think I paid 40$ for my mech gauge? I got a decent one though, they go cheaper at autozone or something like I think.Make sure you get one with a back light hookup, otherwise at night your blind to it.

My 383 has a high volume pump in it and at hot idle I'm seeing 32-34 lbs of a pressure. Course thats apples to oranges. I wouldnt worry about trying to play with it unless you planned on pulling the motor for some reason. Its more of a pain than its worth. I put 30k miles on mine doing the same thing your talking about. Never a hiccup.

PNYKLR-TA

iTrader: (1)

if you ever doubt it, do ahead and add some lucas oil stabilizer, brought my oil pressure up 5-10psi accross the board.

Formula350

iTrader: (3)

You want high pressure, not high volume. And also, apparently our cars are prone to sucking the pan dry with a high volume :S If you're good, you could simply make yours high pressure by taking out the spring and putting in a much stiffer one. If there's a rebuild kit for oil pumps, you might be able to buy just that. Aside from bearing wear and a few other things, the other reason for low pressure is the oil pump gears (if you know what an oil pump looks like you'll forgive my use of the term 'gears') wear down and don't make as much compression like when new.

96blackta

iTrader: (7)

Can someone point me to a post that shows how a dash looks with aftermarket gauges?