Black LS1 T/A

OK ... I am just crying right now. I'm still dealing with this low oil pressure issue. I've had the car parked over two years due to time I could allot to all the things I wanted to do with it while the engine was off the mounts.

When I first crank it, it only registers about 38 PSI. As it gets hot, it drifts downward to about 10 PSI at idle. When I drove it before replacing the oil pump (I haven't driven it since I buttoned it back up this time, but I know what's going to happen), it has about 25 PSI oil pressure cruising. Oil pressure does vary with throttle. There are NO unusual noises. It idles just as good as before the low oil pressure. I took a chance once and throttled from stop on a deserted street. Performance seems as good as ever (I left a looooooonnnnnnnngggggggg set of black tire marks.) But, at idle, it is about 10 PSI. Scary. So I parked it for a long time.

I finally had a mechanic friend of mine (this guy is good) take a look at the Rod Bearings with everything off the front, all the way back to the timing chain, and the oil pan completely off. (It took so long to get to this because since i would have the engine off the motor mounts, I saved up and bought Light-wieght K-member and A-Arms, QA1 Shocks all the way around, coil springs, panhard arms, ect., to get suspension back tight , reduce weight on front end and try to help my traction issues.)

Anyway, back to my main story: he said the bearings have proper clearances. As a matter of fact, he said he rarely saw a bottom end in such great condition. He could even still see coating on the rods. Oil was clean with no shavings or debris. He said it looked as if the engine had never even been run. He said the builder defintely put good parts in it (Golden West Performance, if you remember those guys.)

I had already hooked an external oil gauge up to verify the pressure does indeed follow what the oem guage is saying. So, naturally, we figured the problem was the oil pump. He went ahead and replaced oil pump, checking the that everything looked good. The concerning thing is he could not find anything wrong with the old pump, either. Which brings us back full circle.

I dreaded the dissappointment I would feel upon putting it back together, but when I fired it up, sure enough ... same problem, even though the oil pump was replaced.

My mechanic buddy suggests oil restrictors/galleys problems, maybe even oil plug issues? I don't know about those; he says it must be some kind of internal oil leak.

We agree someone on the forum must have experienced something similar. I would appreciate any advice from you guys.

TooLateVTEC

iTrader: (2)

What kinda pump did you have in there before and whats in it now?

What kinda oil pan is on it?

Ever try adding half a quart of oil and see what effect it has?

ae13291

iTrader: (8)

1 possibility and the most common is the O ring on the pick up tube. what color did you use? also seems like if you dident find a problem with your old pump its the oil gallery freeze plugs. there is one behind the engine cover and also one under the timing cover as well, and should be one behind the pilot bearing but you should see oil spewing if that was out, the 2 other plugs would show no sign of leak they would just drain into the oil pan. they should be located on the lower driver side under the timing cover. it looks like a little gold cap

Sales2@Texas-speed

iTrader: (5)

If all you changed was the pump between having pressure and not having pressure, go ahead and tear back into it and fix the o-ring.

Black LS1 T/A

Stock 1998 pump, original. Also original pan.
I drove this from '99 to about '07 with no oil pressure problems.

I think I bought the 2000 LS1 pump (from the dealer), but I got it about two or three years ago, so won't swear to that. I know it wasn't a '98, because I asked for the later model that worked because I heard it was a better pump. I think he told me they didn't sell a '98 pump anymore anyway.

The highest I ever let the oil level get is about pint over. My understanding is the crank hits the oil if level is too high, foams it up, and that's bad for it. Right?

Black LS1 T/A

What do you mean "fix the o-ring"? What are you saying could be wrong with it?

eseibel67

iTrader: (10)

It's very easy to pinch the "o" ring during installation.

Buy a proper new O.E. ring and try again. You will know if the last effort was a fail by the look of the "o" ring.

jbuhr

iTrader: (6)

I would point to the O ring also. I almost forgot to put a new one in my engine last summer when I put the engine in. It would have been a lot of extra time doing with the engine in the car. Good luck and let us know what happens after the new O ring.

ae13291

iTrader: (8)

2000 pump is the same as the 98 the 01 pump was revised, it was the same as the ls6 pump

SOMbitch

iTrader: (8)

The pinched O ring usually leads to areoreated oil and ticking as well as low OP.... No ticking makes me think main bearings..... He is just above the point of hearing knock but not far from it......OP does OP dip slightly at WOT before rising??

Other thoughts guys & girls.....

slayerized6

iTrader: (12)

subscribing...

Black LS1 T/A

No ticking. No noises out of the ordinary. You can't tell anything is wrong from listening or driving the car other than the visual indication on the gauge.

Please read my comments regarding the condition of the bearings and their clearances.

Thanks!

MUSTANGBRKR02

iTrader: (91)

Did you check the PU tube when you had everything out for restrictions?

Black LS1 T/A

Yes. He said he is very familiar with the o-ring issue and took precautions to make sure it was properly seated. He looked at old one good upon removal and it was not distorted. He did replace the o-ring. Pickup tube was slick as a whistle. (his words).

MUSTANGBRKR02

iTrader: (91)

I would think some internal blockage then. Have you talked with the guys at RPM yet to see if they have any ideas?

Black LS1 T/A

He said blue. We're discussing the oil galleries further.

Man, I just put all that front end stuff back on. I sure was hoping not to have to remove the tranny anymore until I had to replace it.

Black LS1 T/A

No, I haven't taked to RPM. Don't most vendors not really chat like that unless they are getting work?

Some issue with the oil galleries is all we can come up with. Is it possible I just haven't given it a chance to gain its pressure? All I've done is crank it and let it warm up in the garage.

I'd have to insure, title, tag and get it inspected to take it on the road. What a waste that would be if I have to take that engine out.

jman54002

iTrader: (11)

I had a problem like this also on one of my sevice trucks, This is what I did to verify it was the o-ring. Now take the front end of the engine off so you can see the timing chain and the pump. So all you have showing is the crank shaft and the timing chain showing. now the motor will start and run at this point with out the water pump on and without the balancer. You take a squirt bottle of oil and dump it all over the area around the o-ring. This will give a seal and the gauge will jump up. And there is your o-problem. If that is what it is. Now everyone clam down I know this is not the best thing to do but it works. You will need a person to watch the gauge so you don't run it long. I have done this at least 8 times when people tell me it not the o-ring. I have been right 80% so far.

ae13291

iTrader: (8)

i done the same except i cranked the engine enough to build oil psi and after you see the oil from the center of the snout around the pump leak then the psi is build. so wait and let it bleed off and if you see oil coming from around the pick up tube then its your o ring.

01ssreda4

iTrader: (96)

What about the barbell plug thingy in the engine. Cant that cause issues like this?? I have seen the plug sets including the barbell on ebay for like $40