LS2 swap NO OIL Pressure?!!?!!!?!! NEED HELP

[CoBy Williams]

Just finished doing a LS2 swap in my 4gen FBody.I had the Ls2 put in a machine shop to be freshened up, honed cleaned and all new bearings and they installed a ls1 oil bypass valve in the block. I over came a few obstacles in doing this swap but his one has STUMPED me. I drove the car home from the shop after the swap. First crank made 60psi of oil pressure. The next day the cold start only made 40ish psi of pressure. I thought maybe cause it was warm that day. So i drove it to the muffler shop with open headers. i ALMOST made it to the muffler shop before i noticed that the oil pressure started to DIP.(Heart started skipping beats) By time i pulled in it went down to ZERO OIL PRESSURE. Let it sit for a couple hours and cranked it up and started hearing valve train noises.(lifters were dry, not oiling up top).#1 problem i had found was a pinched Oring on the pickup tube.#2 problem i found out that i was supposed to use the red Oring which is thicker and sealed better (but ive heard of people driving MANY miles on a pinched Oring before they noticed oil pressure decreasing). So i used the new Oring and left the oil filter,harmonic balancer, and one valve cover off just to see will oil come out one of the two places. I unplugged the coil pack connectors so it wouldnt start up(scared if it fires up that it'll spin a bearing which is the reason i replaced the old motor) Turned the motor over for 10-15 seconds straight and NO oil came out of the filter area or up top. So i didnt even let the car down to crank it. Simply because NO oil came out up top or bottom which worries me. The gauge only flinched while turning it over. WHAT ON GODS EARTH COULD STOP A FRESH BUILD FROM BUILDING OIL PRESSURE?!?!?!?!?!?!?!?!?!?!?!?!?!?!

[SMWS6TA]

What is the LS1 oil bypass mod?




3 possible things:

1- no oil barbell installed.

2- no oil galley plug

3- oil pump failure, either by o ring, pick up tube, or trash in the pump.


a 4th option is the OPSU is bad but I doubt it because you are not seeing any flow.

[SMWS6TA]

nevermind it looks like you installed an oil cooler, correct?

[CoBy Williams]

To be honest im not sure. The machine shop guy told me it was some kind of valve or plug thats put into the back of the block. He said with out it, it wouldnt oil. And where are those first two possible problems located? And yea your right because its definitely not oiling at all so im sure its not the OPSU. oil cooler is installed. Just scratching my head why could it have oil pressure one day and gradually decrease the next day till it read zero and never came up again.

[jrbonds]

Drivers side of block behind rear cover. Dumbell type bar that inserts there.

[SMWS6TA]

did the shop do the work on the engine? I'd be making some phone calls...

[CoBy Williams]

Drivers side of block behind rear cover. Dumbell type bar that inserts there.

ok thanks. And what about the galley plug? And me & a friend put the motor together from swaping my LS1 parts and accessories ect over to the 6.0. This was my first time doing it, and he on the other hand is much more experienced than me.

[SMWS6TA]

located on the front side of the block.


both require removing the front & rear covers.

[Firebirdjones]

Did you prelube the system with air pressure before you fired it the first time?? Pull the oil filter and cut it open, check for debri. Hope it didn't wipe a bearing on start up.

[SMWS6TA]

^^^^
prelube is your friend....

[CoBy Williams]

Did you prelube the system with air pressure before you fired it the first time?? Pull the oil filter and cut it open, check for debri. Hope it didn't wipe a bearing on start up.

Thankfully No debri was in the oil filter AND yes plenty of lube was used before the very first start up which showed 60psi. i just got done pulling the front cover off and that front plug is in place. Sooooooo thats leads me to think MAYBE one possible problem left? Barbell plug in the rear?

[SMWS6TA]

you said ya'll built it, do you remember installing one?

[Firebirdjones]

I don't think I'd bank on that barbell missing. If it were gone I believe you wouldn't have had pressure at all and not the symptoms you described.

From what I'm reading and understanding......You prelubed it and had pressure (but I think not, I'll get back to that in a minute). Fired it and had pressure, then drove it and had pressure. The more you drove it the less pressure you had and within a few miles.....zero pressure.

That sounds like a classic wiped bearing to me. I've had that happen within 50 miles when a brand new pontiac engine wiped out the thrust bearing.

I think I would be digging a little deeper and pulling the pan to inspect things.

When I say prelubed, you say plenty of lube "was used" What I mean is that you need an air pressurized tank filled with oil that you pump into the engine, the air pressure forces oil throughout the engine before you even fire it. This is how you prelube an LS engine. Older engines you run the pump with a primer through the distributor hole before you fire it.

[jrbonds]

I had 15lbs of pressure with my dumbell missing.

[SMWS6TA]

I know that how FBJ posted above is the proper method in priming the system with oil. However I didn't have that tank you mention or access to one. So in order to prime mine I disconnected the fuel injectors and turn the engine over 10 seconds at a time for several times. About 20 total. I also made sure the battery was fully charged. Then I reconnected the injectors and start the car and ran for 10 seconds, turn off, repeat for a few more times and then let it run. I also had a heavy amount of assembly lube on all bearings.

[SMWS6TA]

Jodi, didn't the first mechanic you had assemble the engine put RTV in place of the barbell?

[Firebirdjones]

If you don't want to buy the preluber, there are plenty of home made versions out there, easy to do. Most I've seen use a plastic 5 gallon bucket, and run lines to the oil filter, and a drain at the oil pan drain plug, then drive a cheap sbc oil pump mounted in the bucket with a drill.

It's good insurance after spending $5-$10k on an engine.

[SMWS6TA]

This seems to be a good and easy one to make.

[jrbonds]

Jodi, didn't the first mechanic you had assemble the engine put RTV in place of the barbell?

No. Just put rtv around the gasket.

[Firebirdjones]

This seems to be a good and easy one to make.

Yup, that's cheap and simple. Only thing I can think of that might help solve his oil site problem would be to run another line out of the oil pan drain back to the tank so you have a continuous flow of oil (won't pump air that way) and you could run it for several minutes without worry of running out if you wish. Otherwise that setup works just fine if you're careful.

He's right though, doesn't take much air pressure. I have an oil drain tank that holds 40 gallons. When it's full I take it to Oil Can Henry's, pump air to it, and it drains into their reservoirs. I regulate it to about 10 psi and that's all it takes, it will empty that 40 gallon tank in about a minute and a half through a 1/2" hose. And I have to keep an eye on it, because once it's empty the hose turns into a raging whipping splatter mess, and that's just 10 psi.