martyp

Hi, I just bought an '99 T/A, with the LS1. I think I got it @ the right price, but the first problem that I noticed was no oil getting to the top end. Pulled the valve covers, it is spotless, but no oil. It has 62K on the clock. The dash gauge is reading 40-50 #, but I never trust them. How can I find out if the oil pump is working ? Does the oil come up the back of the block ? Just want to find out what to do before I tear off the intake, etc. Any help, would be appreciated. One member posted that PewterSS, was in New Stanton, and was good @ LS1's, but don't know how to find him. Thanks, Martyp

glennhl

Do you have oil pressure? The oil pumps on the 99's have been known to fail, but if you have oil pressure you are fine. The oil pump is mounted off the front snout of the crankshaft. The oil that goes up to the rocker arms will drain back into the sump, so I'm not sure what you are looking at when you say the top end is not getting oil. Did you run it with the valve covers off to see if oil is squirting out of the pushrods? By the way, if you do this it makes quite the mess!!!!

Check your oil pressure and don't run the car if it's really low.

martyp

Like I said, it's showing 40-50# on the dash gauge, but not sure. Yes I had the valve covers off, NO oil, that's what has me puzzled. Should i pull the pressure sensor, to see if oil comes out while I'm cranking it ? I would unplug the coil packs, (Don't want it to fire, there hopefully, be oil pouring out).

Z28LS1camaroguy

iTrader: (3)

yeah your not gonna have oil in the heads if the car is off, it goes back down into the oil pan, the heads should be a brownish glazed color but no oil is gonna pour out of them. you could always start the car with the vavle covers off that will show you that oil comes up to them lol.

martyp

I did run it and there was no oil, that's why I'm asking around. I was saying, if I take the oil pressure sending unit off @ the filter, and crank it will oil come out of there, without actually starting the car, and have oil shoot out of the sending unit hole.

Z28LS1camaroguy

iTrader: (3)

yes oil will shoot out of the pressure sending unit hole if you remove it and start the car.

martyp

Thanks, that should tell me if the oil pump is working. If that is, then ther has to be a reason why the oil isn't coming up the back of the block to the valve train. Right ?

Z28LS1camaroguy

iTrader: (3)

i dont see how you would have oil pressure if it wasnt coming up, unless there is a clogg in the oil pump pick up tube or oil pump itself, most likely the culprit will be the oil pump.

KENS_SS_4

If the oil has always been clean and changed at a short interval. The heads should look clean-n-pretty. The rockers are at least 300 degrees when at operating temp, so when the engine is shut down the oil drains leaving nothing but the smell that it was up there.

Here is a little info.
Engine 101
single cam hydrolic roller lifters:
After oil flows to the cam bearings (before the oil pressure sending unit by the way), it flows to the lifters (hydrolic roller lifters) pumping them up and lubing them. with each lifter cycle a few drops of oil is forced out an exit hole at the top of the lifters and flows up the hollow push rods. the oil exits out the contact point with the roller rocker arm lubing the rocker arm assembley and valve stems.

Oil does not fllow up to and fill the heads. It comes out of the push rods and is distrubited by the movement of the rocker assemblies. A few drops each cycle of each rocker. The oil then drains by gravity back to the oil pan.

With just the oil filler cap removed and a flashlight while the engine is running, evidence of the oiling process can be seen at the "in view" rockers. It is not a lot of oil though.

40-50 psi is great pressure if you are talking at idle.

Oil does flow up the back of the block. The oil pressure sending unit is at the top of the back of the block. It can be removed and reinstalled on top of a "T" fitting that can then be plumbed to a gauge while still leaving the factory gauge working.

Hope this is of some use.

angel71rs

In order for there to be no oil flow to the topside, there would have to be no flow to the lifters. In which case you would have a real racket from collapsed lifters. Are the lifters quiet? If so, oil is getting to them, and the topside. Unless all your pushrods are clogged, highly unlikely.

martyp

Yes there is racket. I thought the oil sending unit, was down @ the oil filter, I may be wrong. I just bought her a week ago, and it's been too cold (20 degrees) to crawl around underneath. I've had the valve covers off while running, no oil. The car sat for 1 1/2 yrs., I've heard that maybe the oil drained back, and the lifters need to be primed ?

'Trust'

iTrader: (24)

It sat for a year and a half before the time your talking about starting it? The Oil Pressure Sending Unit is at the top of the motor behind the intake, so if your pick up tube was clogged or the o-ring was pinched you would have fairly low pressure, nothing like 40psi. What I'd do is drain the oil, first and see how much actually comes out, then new filter etc. and fill it up by poring oil directly onto the rockerarms and lifters etc. , do at least a couple of quarts that way then put everything back on and finish filling it up and try it again. Also when you crank it like your talking about, even w/the coil disconnected dont hold the key in posistion, do it in bursts.

CrimeSScene

iTrader: (9)

How long did you let it run?

martyp

I let it run 15 mins. Didn,t want to run it too long. Haven't driven it, so it's basically only been @ idle. Whenever I do give it gas, the oil presuure gauge does go up. I had the valve covers off & ran it, still nothing. It is noisy ( of course ) that's why I didn't run it long. I've heard that if yoiu let LS1's sit the oil drains down. Don't know for sure. Is there any way I can prime the lifters ? Just to get things going ?

Wyoming T/A

iTrader: (1)

i would take the sending unit out and screw a mechanical guage in,even if you have to buy one probably $20 or less, just a cheap one to find out if you actually have pressure,if no pressure you have pretty big problems.probably a bad pump but the more you run it you are going to do serious bearing damage and maybe crank scoring!!!