cm870 needs a head (so I can get ahead)

[hhow55]

(01-30-2017 )Redpower870 Wrote:  Greetings all, I'm a longtime lurker that finally joined and want to share part of my ongoing story with this red engine. The truck is an 07 KW t600, an 06 cm870 with 13-speed Eaton and 3:36 rears on lo-pro 22's. I bought the truck with a "fresh" inframe, new software from 475 to 550 (from Cummins), 100k warranty and oh boy it's time to go trucking! Reality showed up at 108,000 miles later and she had as much blow-by as exhaust (least I thought so)....you guessed it..."sorry you're out of warranty"!

I had a great local shop I used and the diagnosis was grim....she needed to be gone through again. The tech doing the job was a friend and although the money and downtime was steep....I felt good about having it done "right". Teardown ensued....I got a call..."you need to come see this" so over to the shop and lo and behold there were pistons and rods lined up for me to see. Bearings on the bottom were hardly broken in...then not one....but two pistons with the rings lined up as straight as an arrow....two more had maybe 60 degrees of offset and the last two were "correct". Umm yeah Houston we have a problem. No taking chances this time....head was sent off and parts ordered....I go back home. Now the weird part....a few days go by and no news on the head, shop owner calls 'em and big surprise....they can't "find" my head. "Not to worry" says machine shop...."we have another one here and will send it right out". I should have known it wouldn't end well.

I got the truck back and holy sweetness she was a star! Great power, smooooth running and idling.....yep.... the world is mine for the taking! Or was it? We had changed everything but the crank, air compressor, fuel pumps, fuel actuators, turbo (same actuator too).....and injectors. Yes you can say "ah-HA!" if you like now. I made it about seven months and she wasn't running well. My shop was swamped and I went to Cummins....yeah big red "C" in the sky. All tests said 2 injectors were bad...."ya know, we recommend doing all six so you get the warranty"....they saw me coming and I said yes.

I made it eleven months this time. Same symptoms as before...oh but wait....heh heh...I got a warranty! Now I like being a little devious so back to the great red "C" and have em check her out. "Hey you got 3 bad injectors but well we recommend you get all six done." I said wow that sounds expensive but okay if that's what it takes....I got caught though and all they would "warranty" was the three that showed up bad. Oh well, I tried and down the road again...but I felt something wasn't right. I started looking up things online, reading countless message boards and discovered Rawze and a few others that were passionate about not only learning....but sharing that knowledge.

Back to my saga....about seven months after the "warranty" work....my fuel tanks wouldn't stay level. My engine builder had left my local shop and was doing a mobile business on his own but I'm loyal so I had them try to find the issue. New superman tech says its a line and the return splitter...simple right? Didn't fix it. Idling at base or raised idle it was fine....load the engine and make it work....as much as a half a tank difference! A few of you already know how this turns out I bet. I played the game of "let's try this and see" for too long. By now I had software and an interface, the advantage of tapping into what people had written on this forum and others....let's not forget the Tube....omg Thank You Rawze!

I got my builder to come by the house....testing....THINKING....lots of air in return fuel. We open her up on top. Number one injector is...."stuck". Finally, out it pops and the bottom end is covered in a dry scaly rusty looking substance. Yep. Found where the compression is getting in the return lines! The other five looked brand new and nothing out of the ordinary. The bore for number one had pits right above the cup...and the cup itself has major issues. I'm not sure how that engine made adjustments for that mess but I'm real glad we did what we did. A head from a REPUTABLE shop is forthcoming later this week and I'm gonna be right in the middle of a REPAIR instead of just changing parts and hoping for the best. Thanks to all of you for tolerating this long post and giving me faith to take control. Updates to follow.

Keep us posted, thanks