Your thread on 454 BB has me interested in what to do next. That engine was replaced in my 2000 Workhorse MH with a remanufactured Jasper engine. From the start, the hot engine oil pressure is 20# at every RPM between 2K and 3K, doesn’t matter. Idle RPM at 600 and pressure is 10 or less lbs. No break in oil came from Jasper and shop used 5W30 synthetic. Changed after 550 mi with the same type and weight of oil with no effect on oil pressure. Mechanic confirmed instrument panel reading is correct. What type of oil, weight and frequency should I use to improve oil pressure? Any other suggestions or ideas to get improved oil pressure. Original engine (45,961 at time of rod or main knock) operated at least at 40# oil pressure at 2K RPM.
454 Engine remanufactured Jasper engine low oil pressure
- Thread starter RAB TX
- Start date
Welcome to BITOG 
If you have no luck with Jasper, consider a new GM Crate engine
If you have no luck with Jasper, consider a new GM Crate engine
Time for a 15w40.
What were the issues you had?
The shop tried for that, but said they are no longer availableWelcome to BITOG
If you have no luck with Jasper, consider a new GM Crate engine
The old engine had good oil pressure on 5W30. Really confusing now.
It's a different motor. Try a heavier weight just to see. It won't hurt a big block to run thicker oil if your climate allows for it.
After I had the 396 Big block rebuilt that I was putting in my 70 Monte Carlo, It ran pretty low oil pressure with the 10W-30 oil I tried running. I moved up to a 10W-40 and is what I have been running for over 20 years. Oil pressure is much better. I didn't have any noise or running issues with the 10W-30 but my oil pressures were similar to yours.
GM said they are "focusing on the electric future" so no more big blocks which is utter garbage.
NOOOOOOOOOOOOOOOOOOO
could also be a supply chain issue and they can't get the parts to build em
Have you contacted Jasper? 20 PSI @ 3,000 RPM is cause for concern!
Knowing Jasper’s reputation, your shop needs to complain. I’m thinking Jasper messed up assembling that engine.
The 454 HO is not suitable for RV/HD use for many reasons, But the most glaring reason is the rectangular port heads will not match the oval port intake that's installed on L29 454's.
The HT502 is a more suitable replacement.....Though it would need larger injectors & some custom tuning.
The are some NOS L21/LP4 crate engines out there (P/N 19207551), But will require some parts from a/the L29 to make it work (Notably the Timing Cover, Crank Sensor & Reluctor Wheel)
Last edited:
4WD
$50 site donor 2024
Seems he has only half (or less) of normal oil pressure - IMO, switching to a 40 is not enough …
+1
Jasper has never been known for quality, but have been the go-to for many shops because of pricing. I remember a lot of issues in the Jeep community with their rebuilt 4.0 engines. They would come with all different sized bearings, clearly worn pistons, scored cam bearings, etc. It was like they took their cores and just spray painted them, put them on a different pallet, and shipped them out. Embarrassing.
Switching to a higher viscosity oil to fix a low oil pressure problem is like super gluing your butt shut and declaring that you've cured your food poisoning.
The low oil pressure is telling us there is a problem, but the low pressure itself isnt THE problem.
This poor engine either has a bad oil pump or is hemorrhaging oil somewhere internally where it shouldnt be. Jasper definitely needs to be involved.
The low oil pressure is telling us there is a problem, but the low pressure itself isnt THE problem.
This poor engine either has a bad oil pump or is hemorrhaging oil somewhere internally where it shouldnt be. Jasper definitely needs to be involved.
Similar threads
