Well guys I am looking to you for some 4th gen help. My buddy has a 1995 Formula LT1 6 speed. When it is cold is has 40+lb of oil pressure, as it warms up it will drop pressure to below 10 causing the check gauges light to come on. Here is the problem,........ we have just installed a NEW HIGH Volume pump and the pressure reading is still the same when warm as the old pump........so we go back with a mechanical gauge and check it at the block.......same reading when warm. Where is the pressure loss coming from.


1 know the pump is good
2 know the gauge is reading correctly
3 Main bearings checked when the pan was off and all clearances were correct.



Thanks for the input
Brian Felts

 

Massive internal oil leak....

Has this engine ever had good oil pressure?

If not, missing gallery plug from the front of the block, around the front cam journal. If it has, wiped cam bearing.

 

Did you get the oil pump drive stub shaft and seals in correctly? That will cause a massive leak as well. If you replaced the oil pump solely from the bottom and didn't remove the intake to check the drive shaft, you might want to now.

 

Now you guys are talking. There is no oil leak out of the motor so I am thinking there is a internal leak. He got it from Ebay. So as far as we know it has been low psi. I know the books call for 5 psi at idle and we all know that not good. I have never had a chance to listen to a motor with a bad cam bearing but it is very quiet under the hood.


THanks for the input
Brian

 

Did you try replacing the oil pressure sender? The stock GM pieces are not renowned for accuracy....

 

yeah we did even used a mech. gauge. Same reading, I know we have to have a internal pressure leak its just finding where.


BRian