Cm871 oil consumption
02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #1
Cm871 oil consumption
I have a 871 with a million miles on it. It just recently started using up a ton of oil. Blow by seems good. No leaks. Crankcase filter it bypassed. I’m using 1 gallon every 2500 miles. First thought was carbon packing but this truck has been deleted for about 200k miles and never used up any oil until now. What should I look for?
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02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #2
RE: Cm871 oil consumption
if it aint leaking and no bad blow by possibly valve stem seals/turbo leaking check turbo to CAC boots for oil, if not there take off exhaust from back of turbo and start it up and hold a piece of paper behind in the exhaust stream see if you get a buncha oil if so most likely valve stem seals.


User's Signature: 2010 Lonestar - CM871 - 13sp - 3.70s, 2016 T680 - cm2350 - 13sp - 3.36s - skateboarder
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02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #3
RE: Cm871 oil consumption
That's usually how it happens. 800k of eating it's own waste puts alot of carbon in the ring grooves and piston crown. Once you fix that issue it slowly burns off that carbon. Once the rings and such finally free up there is too much ring gap and it starts using oil.

Just my understanding of it.
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02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #4
RE: Cm871 oil consumption
(02-10-2020 )Nilao Wrote:  That's usually how it happens. 800k of eating it's own waste puts alot of carbon in the ring grooves and piston crown. Once you fix that issue it slowly burns off that carbon. Once the rings and such finally free up there is too much ring gap and it starts using oil.

Just my understanding of it.

I have seen this many times.

Had one guy here, he had 900k on his, had just gotten it de-mandated (i helped him fix the horrible program it had in it, that he swore seemd to run fine), but some damage was already done... Also, it with that many miles on it and eating carbon, I warned him about this possibility of the rings freeing up once all the years of carbon packing got burned off them, and sure enough, ,..the pistons cleaned themselves up, and it freed up the extremely worn out rings, and started burning a gallon of oil every 4,000 miles or so ... I had warned him before he started that adventure, but he was already prepared for the consequences. He went to gearheads and had the engine rebuilt about 2 months later, kept the de-mandate (it was done the right way) and it has run fine ever since.

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(02-10-2020 )Jose9640 Wrote:  I have a 871 with a million miles on it. It just recently started using up a ton of oil. Blow by seems good. No leaks. Crankcase filter it bypassed. I’m using 1 gallon every 2500 miles. First thought was carbon packing but this truck has been deleted for about 200k miles and never used up any oil until now. What should I look for?



also... you were warned about the 90+% possibility of having a bad delete files in that thing a while back .... here http://rawze.com/forums/showthread.php?t...6#pid42736

I HOPE LIKE HELL you got that program inspected and verified by myself, unilevers, mommaburt, to ensure "your good guy" did the job right and did not shorten the life of that engine.


User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
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02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #5
RE: Cm871 oil consumption
Rawze I had all my trucks re- de mandated and with good files. Although at the time I was only having an issue with one, I re did all my trucks.
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02-10-2020, (Subject: Cm871 oil consumption ) 
Post: #6
RE: Cm871 oil consumption
(02-10-2020 )Jose9640 Wrote:  I have a 871 with a million miles on it. It just recently started using up a ton of oil. Blow by seems good. No leaks. Crankcase filter it bypassed. I’m using 1 gallon every 2500 miles. First thought was carbon packing but this truck has been deleted for about 200k miles and never used up any oil until now. What should I look for?

I had the same problem. Turned out to be a broken ring on cylinder #6. So I had haggai rebuild it
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 Thanks given by: Rawze




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