HoLLo

iTrader: (17)

So I pulled my intake off a few weeks ago to replace both knock sensors and install LS6 valley cover. When I was putting the intake back on, I noticed the oil sending unit broken. So, i ran to the store, bought a new sending unit and special socket. When I got the car back together, the oil pressure was showing like half of what it ever was. Like 20-30psi at idle, maybe 40-50 at WOT. I know the oil pressure is supposed to be higher than that. Especially considering the old unit showed much higher (normal) pressure, and this is a new unit.

Is there something I could have done wrong or did I get a fauly sending unit from the factory? I was hoping I could try and replace it with the intake still on, also.

DaddySS

Depending on what oil you run, 20 to 30 at idle and 40 to 50 at wot is fine. If you really want to verify, plug a mechanical unit in and check it. Otherwise, one of the senders just reads higher than the other. As long as the sender isn't leaking you'll be fine.

HoLLo

iTrader: (17)

Same oil as what was in it before. It used to idle at 40, and WOT be like 60-70ish. What kind is supposed to read like stock?

98RedBird

iTrader: (77)

That's been the normal oil pressure for every LS car I've ever seen...

40-50 at WOT seems low to me. I would see if you can't borrow or buy gauge and actually check your oil pressure. It may really be that low. If so, I'd swap pumps. If it's reading normal, change oil pressure pickups again.

How many miles on the motor?

HoLLo

iTrader: (17)

My point exactly. I know it's low to LS standards.

Its got 100k, but it was perfect before I replaced that sender. I mean I drove my car into the garage with perfect oil psi, the next time it was cranked it was like HALF. What are the chances an oil pump failed right then?

The sending unit came with a 1yr warranty so I can replace it for free, but I'm just trying to figure out maybe if I did something wrong, and I don't want to pull off if I don't need to.

2002 SS #476

iTrader: (2)

Is it a GM unit? Sometimes it's best to stay with OEM parts, from what I've seen.

conor.davis

iTrader: (20)

I got one from auto zone and had opposite results.. slightly higher pressure reading.
Put a mechanical on it and see what true reading is if your concerned.

HoLLo

iTrader: (17)

Finally put a new one on. Still not any better.

LS6427

iTrader: (2)

+2...if its not a GM unit, that could be the difference. I got a used GM unit when mine broke and it read the same as my old GM original one. I have 140,000+ miles on my engine and I have near 65psi at WOT. Down to about 25-30psi at hot idle. 40psi while cruising normally.

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nysbadmk8

Check it with a mechanical gauge. If its still low.. Change pumps, clean the oil pickup screen, install new o-ring on the pickup tube.


Oil pressure should be 40-50 @ cruise.. hitting 55 psi or better over 5000 rpm.

Gm spec is 8 Psi per 1000 revs

I Personally perfer 10 psi per 1000 revs

HoLLo

iTrader: (17)

Well, actually I think this one is better now that I've driven around more on it. It doesnt drop as low as the last one. It's like this thing can't read over 40psi. it hangs at 40 cruising which is good. But at WOT it never budges forward.. I guess I'll be lookin for a GM unit soon

HoLLo

iTrader: (17)

Just made this video for fun. but you can see the oil psi
http://www.fquick.com/videos/viewvideo.php?id=9617

ls1 1990 VN

Nothing wrong with your oil pressure, 10psi for every 1000rpm is the norm. Fit a manual oil gauge for your own piece of mind.