Shimmed my oil pump.. went from 35psi to 45-46 psi..

[jimeneztrans84]

Hey guys I finally got to shimming my oil pump on my 2011 cm2250 with 527k miles. Did my oil change and did the oil pump mod. I used 8 dimes. I went from 15-16 psi idle to 18 psi @ full operating temperature and 35 psi to 45-46 psi going down the road. Is that normal going from 35 psi to 45-46 psi?

[jimeneztrans84]

Update @ 180 temp going down the road it's at 45 psi when it gets 200-210 temp it drops to 41-42 psi.

[Rawze]

sounds good to me.

[jimeneztrans84]

Cool thanks rawze!!

[Hammerhead]

Sounds perfect. I just re-shimmed mine.
That was my original goal, between 40 & 45 at operating temp.
I went from 7 Canadian dimes 0.334" to 8 US dimes 0.414 and have basically the same pressure at operating temp you have. I'm at 22psi at 700rpm 210* idle.
I was hangin out on mumble with Rawze, and he mentioned that the rod and mains can get washed out at 50psi or above. So anybody performing this mod, be damn sure you warm your truck for at least 15 minutes after this, because with the oil temp at or below 150* the oil pressure will easily climb past 50!!!
People performing and operating engines with modifications need to be attentive and responsible in order to maintain longevity.

[jimeneztrans84]

Yeah I warmed up my engine before draining oil and after oil change and pump shimming. That thing went to 50-55 psi at startup. The only thing that is weired is my idle psi is the same 16-18 psi. Shouldn't it have gone up too?

[slowpoke]

i shimmed mine 3 weeks ago tried to use 7 us dimes but didnt seem to want to compress ended using 5 dimes oil pressure went up about three lbs when hot was 31 now 34 but at idle not much did notice now after first week when start from cold (70 f) oil pressure 42 lbs at idle 600 rpm bump it to 800 rpm pressure drops to 36 then to 40 then to 36 then slowly back to 42 if i keep it low idle for 30 seconds then this dosnt happen. pump one year old cm871 inframed. could i have done something wrong

[Hammerhead]

(10-09-2016 )jimeneztrans84 Wrote:  Yeah I warmed up my engine before draining oil and after oil change and pump shimming. That thing went to 50-55 psi at startup. The only thing that is weired is my idle psi is the same 16-18 psi. Shouldn't it have gone up too?

It should have gone up across the whole range I would think...have you tried connecting Insite and looking at the oil psi in the Datalogger?
If your truck is multiplex wiring, perhaps it doesn't good good stable readings in the lower range?

[jimeneztrans84]

No haven't tried connecting to insite...might check that out. It was at 22 idle then now back down. Something seems off...