New Cast Iron Oil Pump pressure low

[Tanker93]

(12-13-2020 )alamow Wrote:  Mandy, thanks so much for posting. Information like this is gold dust. Much appreciated.

Cummins put my truck on the dyno. 520hp at the wheels. 35psi at rated HP. So I have an operational engine brake at 2050rpm..... within spec according to Cummins.

I'll try 5mm shim when the Xmas rush stops.

Did you get a chance to shim it? We're in the same area and I noticed lower pressure on a couple of our crate engines and a recently rebuilt engine. Was in Hedland this week and saw the pressure on the rebuilt engine go down to 105kpa at idle when oil temp was around 110 degrees, comes back up to a more acceptable level once oil cools down a bit though

[Rawze]

(03-27-2021 )Tanker93 Wrote:  ...
engine go down to 105kpa at idle when oil temp was around 110 degrees
...

15 psi is TOO LOW for an isx at idle ... SOMETHING IS WRONG@!. Should be above 18 psi, more like 20-22 psi.

[Rawze]

(03-27-2021 )VNL64T Wrote:  Hi all.
Reduce noise ..
Do not place gaskets underneath the pump to the engine block ...
Use Loctite 518

"New pump does not use shims to set gear lash."
"Lubricating oil pumps with threaded regulator plugs do not use shims to adjust gear lash."

mm in
0.08 MIN 0.003
0.57 MAX 0.022

Be sure to check the gear clearance !!

I installed without gaskets using Loctite 518, the noise disappeared ..

I have had just as many people say they had to install the shims to reduce the oil pump gear=-train noise... so just because it worked one way for you, does not mean it is the best solution for someone else.

The biggest problem is that the gears seem to be cut differently. Adding or removing some clearance might help, but get it too close (below 0.008" or so lash), and it will accelerate gear wear.

[alamow]

(03-27-2021 )Tanker93 Wrote:  

(12-13-2020 )alamow Wrote:  Mandy, thanks so much for posting. Information like this is gold dust. Much appreciated.

Cummins put my truck on the dyno. 520hp at the wheels. 35psi at rated HP. So I have an operational engine brake at 2050rpm..... within spec according to Cummins.

I'll try 5mm shim when the Xmas rush stops.

Did you get a chance to shim it? We're in the same area and I noticed lower pressure on a couple of our crate engines and a recently rebuilt engine. Was in Hedland this week and saw the pressure on the rebuilt engine go down to 105kpa at idle when oil temp was around 110 degrees, comes back up to a more acceptable level once oil cools down a bit though

No. The pipe to the exhaust pressure sensor was blocked with soot resulting in high water and oil temp. Once the blockage was removed the oil pressure stabilized at 32-34psi regardless of the oil temp. The engine runs much cooler and recovers from a hard pull so much quicker. From water temp of 100c to 87c takes 200m rolling off a hill. This has the added benefit of a cool engine when pulling up. Previously high idle and Horton was required to increase oil pressure from 15psi to 18 psi at idle.

More recently the pressure differential sensor was found to be leaking at the front O ring. This caused all sorts of EGR/VGT issues at idle.

[tree98]

(03-28-2021 )alamow Wrote:  No. The pipe to the exhaust pressure sensor was blocked with soot resulting in high water and oil temp.

Curious how this was found?

[alamow]

(03-28-2021 )tree98 Wrote:  

(03-28-2021 )alamow Wrote:  No. The pipe to the exhaust pressure sensor was blocked with soot resulting in high water and oil temp.

Curious how this was found?

High EGT at low throttle, 40 psi Boost, 1 litre/1km fuel consumption. EGR Tune up

[dhirocz]

Wow. Wealth of info in this thread. I was lucky enough to pick up an old style pump before I tore mine down so hopefully I put in the 8 dimes tomorrow and it'll be ok.

Curious, what exactly wears in these pumps? I'm replacing mine solely as a function of mileage and proactive maintenance, is a used pump that was still functioning fine worth more than a core or rebuild able?

[JimT]

Quick update regarding my newer oil pump. After nearly 10 months and 4 or 5 oil changes I can say this:

Pump/gear noise is loudest/most apparent with fresh oil (10 gallons Delo 15w40 + 1 gal Supertech 80w90). Noise is loudest when standing directly in front of truck or behind the truck.

After about 1,000-2,000 miles the noise fades into the background. Typically not noticeably louder than anything else, but still present if you know what to listen for. Also slightly louder when cold compared to hot.

Oil pressures are extremely consistent. 25 psi at hot idle (720 rpm) and 36 psi hot around 1600 rpm. When cold, even during this past winter, the pressure is usually only max about 7-8 psi higher than it would be when hot.

Oil pressure over the course of 15,000 miles varies only about 1 psi. The old oil just before a change was reading only about 1psi less then fresh oil.

All-in-all the pump I received, while a bit noisy, has been exceedingly consistent in operational performance.