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shawnkw · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

2011 cm2250 isx15 symptoms are a really rough idle, bad mileage down to 5.5 from 6.7, and the jakes aren't as strong as they used to be. truck is a day cab local fuel hauler. I idle a lot pumping off but I pump at 900rpm.

I know I need to have the overhead ran. Should I also check the cam as well?

Signature620 · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

How many hours on the engine? Air in fuel and bad fuel pump actuators are common causes of cm2250 rough idle.

Do you have access to INSITE?

Is the oil pressure normal?

Check for other fluids diluting the oil or a leak in the overhead in regards to your engine brake problem. The solenoids can leak when actuated, the valves in the jake levers can break, rocker shafts can come loose, etc. *Weak Engine brake complaints are very very rarely solved by adjusting the overhead* But by all means, adjust it if it's due.

Rawze · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

what is your regen history look like?

Did you ever solve the moisture in your oil problem?
http://rawze.com/forums/showthread.php?t...7#pid37297

Did you ever do all the tings needed when a person buys a used truck like adjust the valves, clean up all the sensors and pipes, replace old emissions sensors, have the DOC and DPF baked, SCR and Decomp tube inspected, clean Doser injector behind turbo,.. clean the SCR doser injector, replace the DEF filter, etc.?

Brock · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

I second the "is oil pressure low"

When that happened to me it was 3 spun cam bearings.

shawnkw · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

10200 hours on engine when I bought the truck it sat and idled a lot in the oil field mileage is 347,000 the only time I idle is while pumping (830-902 rpm) and in the mornings warming up for about 12-15 min. I just had the fuel pump replaced because it had the 3 piston. So a 2 piston fuel pump was put on by Kenworth and if I had to guess more than likely it was not shimmed the way Rawze explains.

no access to incite

Oil pressure when I bought it was 38-40 now its 35-38ish (analog gauge) hard to tell exactly

Not exactly sure on regen history. But it regens about every 750 miles unless im out on a long haul (for me 100 plus miles) then it will regen about 1100-1200 miles

Moisture problem was solved it was confirmed through oil sample and cylinder leak down test that it was condensation. thankfully

When I purchased the truck I did the egr tune up and cleaned what I could and replaced the sensors that needed replaced. it has a re-manned DPF on it and was cleaned and baked. I have not done the doser or checked all the valves. As for checking the valves Im not really sure on that process but I will have to watch the video and buy the adaptor so I can bar the engine and check it all. Hell if Im going to do that I may well run the overhead myself. Ive heard that the cam or bearings could be the problem.

Any recommendations on shops in Jacksonville Florida? I know MR Hagg is the closest one on the forum to me in south Atlanta. I probably should just bobtail up there and get everything fixed correctly and de-mandated.

alexanderjefferson · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

i have 2011 prostar with cummins engine oil temp goes from 200F to 225F and the oil pressure drops fro 38psi to 30 psi when down the road and from 20psi to 14psi when idling just replaced bearings the big one and the small one and replaced the oil pump and the oil pressure sensor then meachanic told me i need to replace the oil cooler i just wanna know if his opinion is right because i put a lot mony tell now and also i replaced the turbo and actuator. any advice with this matter will help
thank you

Magard · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

Sounds like your falling victim to a mechanic. Oil cooler doesn’t control oil pressure. Could just be wear in the overhead. Are you running gear oil at all. I would suggest a gallon per oil change. I use the Walmart 80/90.

I’m assuming that the oil is changed regularly. Like 10-12k. Otherwise it could e some carbon packing issues.

Rawze · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

(09-01-2019 )shawnkw Wrote: 2011 cm2250 isx15 symptoms are a really rough idle, bad mileage down to 5.5 from 6.7, and the jakes aren't as strong as they used to be. truck is a day cab local fuel hauler. I idle a lot pumping off but I pump at 900rpm.

I know I need to have the overhead ran. Should I also check the cam as well?

Those descriptions are pretty vague ...

kinda point towards a stuffed up exhaust of intake ... or a clogged up IMAP, or possibly an EGR valve opening too far.

Any check engine lights?

Does it pass a rail leak test?

Injector cut-out tests?

you say you put a re-man DPF on it ... what about the DOC and SCR elements? For all you know, the DOC could be getting face plugged?.

You have an engine that requires software to work on it... Invest in the software and an older windows7 laptop --- learn how to do things yourself.

Rawze · 09-01-2019, **(Subject: rough idle bad milage weak jakes )**

(09-01-2019 )alexanderjefferson Wrote: i have 2011 prostar with cummins engine oil temp goes from 200F to 225F and the oil pressure drops fro 38psi to 30 psi when down the road and from 20psi to 14psi when idling just replaced bearings the big one and the small one and replaced the oil pump and the oil pressure sensor then meachanic told me i need to replace the oil cooler i just wanna know if his opinion is right because i put a lot mony tell now and also i replaced the turbo and actuator. any advice with this matter will help
thank you

if you change the oil filter does the oil pressure come back? - Very common problem if the engine is making too much soot and clogging up filters. - It will also take major tool on all internal parts if you don't solve that problem.