11-20-2023,
Hi all, first time writing
Went to the Chicago Cummins store and gave my engine serial number (79178099 made May 2006). The guy gave me the 2 parts numbers that I need 4089985RX & 4089986RX . Later I looked at the Cummins website and with the parts fitment check it tells me those are not the parts for me. Tells me 4089985 & 4089986. No "RX" suffix at the end. Also I found "PX" suffix.
So whats the difference between RX, PX and no suffix?
That was my question but here is the story if you would like to read
Time has come at 1 310 000 miles to replace the metering actuator/selenoids ( i believe) still red painted and factory. My truck at cold (summer-fall time) start is smooth as butter for the first 10-15 sec and then it starts to bruh-bruh-bruh and rpm goes slightly up-down and chirping noises every second. When it warms up to 145-150F oil temp it smooths out at idle. This for the last 2 years like this. Recent few months it started to loose power slightly. Will still do 65-70mph but feels like its a motorcycle engine..very Loud and watered down. Makes too much rumbling noise while cruising and ticks like Honda unadjusted valves when accelerating sometimes.
Pulled double fedex trailers "like a train" until Decemmber last year, had plenty of power all the time. Recent 6 months driving not more than 300 miles a night and half of the time bobtail, half time empty or once in a blue moon 10k lbs light load. Fuel consumption is north of 8.0 mpg but I feel it should be more given those facts. Two different shops made head "tune_up" recently twice and all fine they say. "You injectors are good they say". I believe those original injectors do NOT spray like or close to new for that long. No way
Someone told me to look up Rawze procedures. I did asked my mechanic to come to my garage to try this procedure. Wants to charge me as much as half of the actuators price so I figured it wont be a savings, lets just throw $ at it. I only change oil myself, some times tires... hood latches, window regulator and stuff like that. Don't have the knowledge to do the leak down test.
I did the cylinder shut down procedure. Only on cyl 1 it didn't make so much difference while all other 5 cyl the truck idled terrible when each was off. No white or black smoke. Didnt add any coolant for the last year. Not loosing oil. Sent oil analysis and came back really good, so for now no concerns on internals..just for now
Went to the Chicago Cummins store and gave my engine serial number (79178099 made May 2006). The guy gave me the 2 parts numbers that I need 4089985RX & 4089986RX . Later I looked at the Cummins website and with the parts fitment check it tells me those are not the parts for me. Tells me 4089985 & 4089986. No "RX" suffix at the end. Also I found "PX" suffix.
So whats the difference between RX, PX and no suffix?
That was my question but here is the story if you would like to read
Time has come at 1 310 000 miles to replace the metering actuator/selenoids ( i believe) still red painted and factory. My truck at cold (summer-fall time) start is smooth as butter for the first 10-15 sec and then it starts to bruh-bruh-bruh and rpm goes slightly up-down and chirping noises every second. When it warms up to 145-150F oil temp it smooths out at idle. This for the last 2 years like this. Recent few months it started to loose power slightly. Will still do 65-70mph but feels like its a motorcycle engine..very Loud and watered down. Makes too much rumbling noise while cruising and ticks like Honda unadjusted valves when accelerating sometimes.
Pulled double fedex trailers "like a train" until Decemmber last year, had plenty of power all the time. Recent 6 months driving not more than 300 miles a night and half of the time bobtail, half time empty or once in a blue moon 10k lbs light load. Fuel consumption is north of 8.0 mpg but I feel it should be more given those facts. Two different shops made head "tune_up" recently twice and all fine they say. "You injectors are good they say". I believe those original injectors do NOT spray like or close to new for that long. No way
Someone told me to look up Rawze procedures. I did asked my mechanic to come to my garage to try this procedure. Wants to charge me as much as half of the actuators price so I figured it wont be a savings, lets just throw $ at it. I only change oil myself, some times tires... hood latches, window regulator and stuff like that. Don't have the knowledge to do the leak down test.
I did the cylinder shut down procedure. Only on cyl 1 it didn't make so much difference while all other 5 cyl the truck idled terrible when each was off. No white or black smoke. Didnt add any coolant for the last year. Not loosing oil. Sent oil analysis and came back really good, so for now no concerns on internals..just for now