Threaded Mode | Linear Mode

Bigstank · 01-20-2018, **(Subject: CM871 oil pressure )**

Hey guys need some help here. Got a 871 in here that's been de-mandated by @Mr.Hagg. problem I'm having is oil pressure usually runs 35 but lately it's dropping down to 25psi at 1300-1400 rpms. Idle is at 20 but if I idle up to 900rpm it goes up to 30-35psi like it should. But if I kick it up to 1400 it drops to 25psi when at normal temps. Now when I let it sit for 30 minutes off then start it she's normal again 35psi and 20 at idle. Is this a bad oil sensor or do i need to get it to Mr.Hagg for inframe time. Shes only got 762,000 on here and she runs great with high fuel mileage up in the 6.5-7's. She only uses a gallon of oil between services @ 15K..... thanks

Wiseman · 01-20-2018, **(Subject: CM871 oil pressure )**

Sounds like bad oil sensor. Replace it and go from there. Fuel filter is obstructing access but you should be able to do it.
Buy genuine Cummins !
To pull the plug off first pull out the red clip to be able to squeeze and pull.

Rawze · 01-20-2018, **(Subject: CM871 oil pressure )**

I would not play around with that. Could be anything from bad oil sensor or filter collapsing to an internal oil pressure loss issue. Get it found and fixed right away!>

Bigstank · 01-21-2018, **(Subject: CM871 oil pressure )**

This is what the psi shows @1400 70mph

jimeneztrans84 · 01-21-2018, **(Subject: CM871 oil pressure )**

That's not good. Y are you still driving it?

Bigstank · 01-21-2018, **(Subject: CM871 oil pressure )**

Yep running fine no problems no low oil warning lights. 6.6 mpg 79k gross. No power loss and oil level is full and oil psi is at 25 now lol idk if it blows it blows I'll just slap a new motor in here

Moose · 01-21-2018, **(Subject: CM871 oil pressure )**

It's not good... What's the oil temp at speed when it's that low. Rawse is right on here. I have an 871 with 840k and it doesn't drop that low at speed. It idles that low when hot.

If you let that go into an oil related failure you will be paying the core charge for the ventilated block along with the motor cost. This isn't an N14 or cat....

Rick8044 · 01-23-2018, **(Subject: CM871 oil pressure )**

I got the same problem, I change the oil pump and still the same, at 4000 miles I change the oil filter and it comes to normal. But still a problem

Rawze · 01-23-2018, **(Subject: CM871 oil pressure )**

(01-23-2018 )Rick8044 Wrote: I got the same problem, I change the oil pump and still the same, at 4000 miles I change the oil filter and it comes to normal. But still a problem

Then find out what is clogging the filters up!!!! -- If the engine is getting soot-packed, then fix the problems that are causing it to soot up so quickly!.

An oil analysis form an actual lab and not one of those fast-food oil change machines will tell you what is getting in your oil.