tomulrich

iTrader: (2)

Just built and installed a 427 LS1 in my 98 vette. I personally built the motor. Every item was done by the books. I am trying to get oil pressure ...I am cranking with no plugs in the motor. I am unable to get pressure.

All plugs have been installed...rear plug(plastic with o-ring under rear cover), front metal press fit plug(under front cover), oil pump shims were placed properly so that the oil hole is lined up, oil pump o-ring in place. Also installed the extenal plugs on the side of the block. Pump is SLP ls6 modified I checked the by pass valve....all OK. checked the oil pressure sensor plug....no problems.....The sensor was working fine when I took the car apart...dont see why it would be bad now????

Should I be able to get pressure by cranking a few times for 30 seconds?..is this enough RPM.

Will the engine start initally without oil pressure or is there a fuel pump shut off when the pcm shows no oil pressure.

I have read all the threads on this......I know some people say not to crank...others say to hook up to a oip pressure canister and pressurize the system.......
Should I just start it and see if pressure is produced...

Thanks for the help tom

jerflash

you will not get any pressure
its not spinin nearly fast enough
just put all the plugs in and start her up
you ahve done all you can do

Richie Carbone

iTrader: (3)

Just keep cranking it with the fuel pump and ignition fuses removed. Sometimes it can take a while ( 10 or more times) to start building pressure.

Did you put oil in it?

99hawk409

i had the EXACT same problem.

Here's what we did.

Double checked the oil pump O ring. We put in another new one.
know what? We noticed a sizable difference in thickness of the 2 of them.
We oiled the o ring to help it seal and possibly what did it for us.....put oil in the pump itself and then re-install. After that the oil pressure shot right up and yes.....we had plenty of pressure showing on the oil press. gauge.

I'd say, get pressure THEN start er up.

Post up when you get it going.

tomulrich

iTrader: (2)

I am trying not to remove the pump oring,,,,,It was a thick oring went in without any problems. If anything when I installed the pump there was no oil in the pump...cleaned it with break clean so when I installed it I didnt have oil dripping..

Thanks...keep up with the replys...and ideas..

99hawk409

I think the pre-oiling of the pump helps to "prime" the pump and well....that fixed my exact problem as yours.

I'm dying to know how it works out for you.

good luck.

vettenuts

iTrader: (4)

Not sure if you can even do this, but wondering if you can remove the filter and use a vacuum pump to pull the oil from the pan through the pump.

smask04C5

iTrader: (1)

after you cleaned oil pump with brake clean, did you assemble dry?

Inspector12

iTrader: (29)

Jerflash has my method I dont' think turning the motor over with out any fire for extended periods of time to try and get the oil pump to prime. It just doesn't turn over fast enough to prime the pump without grease installed in it and I don't like that method personally. If you don't have any doughts about how it was put together just install plugs and fuses and start her up every motor I have built has built oil presure in less than a second of the motor starting up. Everyone has there opinions on this procedure they sell a primer for these motors that uses air presurre to pump the oil up to the top side if you are wanting to be very **** about it and I am not saying that it is bad I just don't think that it is nessacary or is it going to make a difference in my opinion though. Good luck!
Jeff

Boostaholic

iTrader: (4)

When I intalled my 408, we cranked it over with the filter off till oil came out the filter hole then screwed in the (full) filter then fired it up. It worked fine.

We checked it at the filter first because we were super paranoid, it is probably not necessary if you did a good job with assembly.

Slowhawk

iTrader: (12)

I ussually just fill the filter with oil and fill the pump when building the motor.Just start it up and pressure should be up in 5 srconds or so.I think you would do more damage cranking it 20 times instead of just starting it the first time

Inspector12

iTrader: (29)

That is my theory too.

kp

iTrader: (34)

does the electric oil pressure guage even work when you are cranking the car?

01_SuperSlow

iTrader: (7)

That's exactly what I do. Fill up the oil filter at least to 3/4 capacity, put it on and crank it up. Pressure always comes up within 2 seconds.
I agree that cranking it over and over will do more damage than good.

tomulrich

iTrader: (2)

thanks for the replys....yes when I installed the pump it was "dry". I am going to just crank it up....the filter was filled to the top with oil from the start......

Thanks for the replys..Tom ..I will keep you posted.

DanZ28

iTrader: (5)

I had the same delima when I put my new motor in. Oil pressure guage never moved when cranking it over with the coils disconnected. I made sure the oil filter was full, everything else was good, and started it. Got oil preesure right away!

Good luck! You should be fine...

Dan

99SS1857

I worked on an engine about a year ago and installed a new blueprinted oil pump while the cam was installed. Same deal no oil pressure . i did all the stuff mentioned above including trying to suck oil through the system with a vacuum pump, priming the pump with pressure, etc. etc.
The final fix was to put GM part # 12557752 (the o-ring) on the pick up tube, even though the one I had installed looked perfect, and a dab of lithium grease in the suction side of the pump. Picked up in 2 seconds and no apparent damage was done
TC

Blktie8

iTrader: (1)

Tommy we started mine up saw no oil pressure and shut it down
Started it again and in about 20 seconds pressure was up to 45lbs
Longest 20 seconds I ever spent.
I believe you're good to go ,if you haven't already send pics
jwsr

shandy294

20 seconds is a long time;was it constantly building up to the 45 lbs or did it suddenly pop-up after 20 sec?
I guess if the engine is pretty-well pre-lubed, he could fire it and see.

Camaro_Zach

iTrader: (19)

um he said he shut it down then fired it up AGAIN 20 seconds later. not had it running for 20 seconds...