no oil pressure in my 4.3 - Chevrolet Forum - Chevy Enthusiasts Forums

no oil pressure in my 4.3

Old  March 31st, 2010, 11:23 AM
  • CF Beginner
    Join Date: Feb 2010
    Posts: 22
no oil pressure in my 4.3

i have a 95 chevy 4.3L vortech engine with 174,000 miles. i replaced the oil sending unit because i was getting a lowe reading on my oil pressure gauge. 0psi at idle and 25psi at anything above 1,000 RPM when the truck is warmed up. i am ordering main bearings and rod bearings and an oil pump. i am hoping this is the issue. i have decided to put 150 bucks into the bottom end rather than replace the whole engine. is this a good idea and does anyone know of any oil pressure issues that are known to happen to the 4.3? my engine is bone stock if that helps.

Old  March 31st, 2010, 2:29 PM
  • CF Veteran
    Join Date: Jul 2009
    Posts: 1,825
    Danbury Texas
Never had an issue with my stepdads '95 V6. He sold it with 225,000 miles. ANd it had a lot to go. I wouldn't be against droppign 150 into the bottom end. But on the other hand, in about 100-125,000 miles you'll prolly need a rebuild.

Old  March 31st, 2010, 9:02 PM
  • Super Moderator
    Professional Mechanic
    Join Date: Nov 2008
    Posts: 2,955
    Bowie, MD
Was the engine knocking at all? If so it probably will not last long at all. Once they are knocking the rods become egg shaped. If it was not you should get some plastic gauge and check the bearing clearances you may need to use a over sized bearings.

Old  April 1st, 2010, 11:39 AM
  • CF Beginner
    Join Date: Feb 2010
    Posts: 22
it wasnt knocking like that, just lifter noise. thanks tho!

Old  April 1st, 2010, 5:01 PM
  • CF Monarch
    Join Date: Jul 2007
    Posts: 6,151
    Princeton, NC, USA
There are issues with the stepper motors in the dash oil pressure gauges. I'd check the pressure manually with a good old tube gauge.

On the 95-98 model S-series, the noise can be mistaken for lifters when it is actually is a throttle cable vibration.
If you have lifter noise on cold start, its not all too unusual on vortec engines, but it will go away after a mile or so of driving.

Old  April 4th, 2010, 7:46 PM
  • CF Beginner
    Join Date: Feb 2010
    Posts: 22
well, i didnt wanna leave you fellas hangin without an outcome of my problem. i pulled the oil pan off and replaced the bearings. they were all scored. the crankshaft too. i replaced the oil pump and i get exactly what i had before. also part of the noise is a loos timing chain. for now i will run it through the summer, and in the meantime get my 85 k20 rolling so i can put my 1500 on hold and rebuild the motor. thanks again guys! i frickin love this site.

Old  April 4th, 2010, 8:22 PM
  • CF Junior Member
    Join Date: Oct 2009
    Posts: 32
    Hampstead, Maryland
sounds like the cam bearings r prolly messed up too...

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