Oil ressure drop to 0 on 2002 5.9 all new complete rebuild

Asked by Oct 09, 2017 at 07:52 PM

Question type: Maintenance & Repair

Shop completely rebuild new bearings new pistons
new oil pump etc all new parts. Run normal
pressure for five minutes then drops to 0 new
sensors added also. Is there a oil relay valve on oil
pump?mains were plastic gauge all new stock
bearings main etc. Want

1 Answer


Yes there is a pressure relief valve for the oil pump, but it will not cause a total drop in oil pressure even if the internal spring totally broke. This sounds exactly like an engine I had a machine shop redo for me, everything was top of the line stuff but let it run for 15 to 20 minutes the oil pressure would drop to zero and the lifters would start clicking, they said it was a bad oil pump, so I got another one and put it in, and same thing happened, no change, so now I'm thinking they messed up the block when they bored out, took the engine back out and gave it back to the machine shop that did the work, they took it apart and checked everything over and found when they line bored the cam bearing journals they cracked two them, so cold it was fine but warmed up the cracks would spray oil all over the insides of the engine, ruined the block for me, fortunately I happen to have a core laying in my shop so they took that one and put all the goodies in that block and it didn't need line bored so they didn't mess it up. seemed that they had been messing up a lot cause 4 months later they closed shop. So I hope this hasn't happened to you and you do actually have a bad oil pump.

Your Answer:

Maintenance & Repair Experts

  • #1
  • #2
  • #3
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.