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My Current cm871 situation - pearce trucking - 05-29-2018
I posted a thread about cm871 oil pressure.
My motor dropped a valve in cylinder 5 (tentative diagnosis). Oil is coating the exhaust manifold and hot side of turbo and exhaust pipes. Likely the egr cooler also. The bridge between the intake valves fell off on cylinder 5, and my new turbo is destroyed by debris through the turbine blades and the vgt ring vanes. Things I've replaced while working on it the last 3 months before running 580 miles and experiencing the above:
-Air Compressor
-Air Dryer
-Transmission Cooler
-Transmission Oil Lines
-Fuel lines from IFSM to Junction block
-Air Line from Compressor to dryer
-Rear Motor Mounts
-Refurbished Starter
-Rebuilt IFSM and replaced everything internal and external except main pump and 3 actuators
-EGR Valve and crossover hose
-Intake manifold gasket and gasket behind ECM cooling Plate
-Fuel hoses to ecm plate and doser manifold, also fuel lines from manifold to to doser injector
-All driver side sensors (Oil temp and pressure, Delta-p, EGR temp, Doser fuel pressure, Cam
position, jake harness)
-Rebuilt wiring harness for same (cleaned, new loom, new electrical tape, couple new plugs and
lock tabs) wires were good
-Cleaned and painted driver side while torn down
-Replaced oil pump necessitating passenger side repairs (covered in oil pressure thread)
-New oil pan gasket and pickup tube oring, cleaned and painted pan
-New oil cooler and oil thermostat and gasket, replaced bypass valve, all fittings
-Replaced orings and gaskets on water inlet. Cleaned and painted same. Cleaned up mating
surface for water filter that had a leak due to corrosion
-Replaced EGR Cooler which had a leak when tested at Cummins (I witnessed), also all fittings,
crossover tube gaskets, return coupling and gaskets, bellows clamp and gasket, Cleaned and
painted all
-Removed exhaust manifold and had ceramic coated, Ceramic coated new bolts and spacers,
Cleaned up Mating surface in head and replaced gaskets
-Replaced coolant thermostat and sealing ring, temp sensor, exhaust gas pressure sensor, both
crossover tubes, and 90 degree hose, Cleaned and painted
-New coolant hoses and brass fittings to transmission cooler, apu, and heater (had to reroute
due to poor design around rear of egr cooler)
-New turbo (after disassembly and finding broken vane ring in the hot side, spending 2 days
trying to grind old vgt vanes to mate with new hot side, but still only getting 3/4 travel on
sector gear)
-New actuator (after calibrating old actuator and panicking for 36 hours before figuring out why
there was so much fuel in the intake from the egr and why the engine wouldn't stay running
{The actuator would get stuck with the vanes fully closed, cutting off exhaust flow,and ecm
compensated by commanding max fuel})
Probably forgot a thing or two, but that is the upshot of it. Engine ran perfectly for 3 days and 580 miles, then rattle rattle, stop engine light and me panicking some more on the roadside in central Florida. The receiver for my load was only 39 miles out of the way from a beeline tow to Cummins where I live. So I delivered on the hook and the receiver shagged my trailer in and out of the door. An extra 2 1/2 hours to the tow truck, but peace of mind and no logistical headache of figuring out redelivery. Cummins pulled the turbo and removed the valve cover. The bridge was off of #5 intake valves, and the new turbo was destroyed, turbine and variable vanes. Won't know more till pulled apart but I had it towed out of cummins as their estimate was $22,500 for replacing head, 1 injector, 1 piston and liner kit, new turbo, and egr cooler/dpf cleaning. Got another estimate for full inframe around $20,000. Spoke with Katelyn (sp?) at Haggai on Thursday and Friday, and am waiting for estimate and to talk with Mr. Hagg.
I think I know why this happened at this time by the way. I had a vibration between 1300-1350 rpm in 9 and 10 gears direct drive and ~2.60 rears. I chalked it up to bad motor mounts. After repairs above, vibration was greatly reduced. However, I rewatched some of Rawze's overhaul videos today. While inspecting counterbores and liners on his five and six cylinders, he pointed out fretting on both, and noted that his #6 counterbore was .003 lower on one side than the other. While discussing this he noted that more severe wear than his had could cause the liner to vibrate. Maybe that was the source of my vibration, and caused a break in one of my valves. The cylinder pressures were up after the turbo was replaced. The old turbo only produced about 24 psi reliably due to the broken hot side ring. The new one produced 36-38 psi as it should. While the components were designed to handle the pressure, my hypothesis is that the vibrating liner became more pronounced with the newly increased cylinder pressures, and whatever fatigue had occurred prior was accelerated. The amount of oil in the exhaust would indicate to me that the piston was probably damaged. No coolant is present in the oil pan, so I hope that the block isn't damaged (or the crank and rod for that matter). I would assume it is likely that the injector tip was damaged. The valve stems are all still in place also, so damage must be in the cylinder near or at the seat.
I'm considering doing the rebuild myself, although I would have to make provision for machining counterbores and block deck. Also I'm concerned about checking that the rods are straight and the crankshaft is also. If I can take it to Haggai, and be present to assist during reassembly, that might be my best option. I know Haggai has a lot of experience with these motors and I wanted to visit him after the inframe anyway. Obviously cost is a consideration, but at some point, having a professional do the heavy lifting might be wise. I've also looked at IPD and Interstate McBee kits if I do it myself, and they are cheaper. I know Unilevers has used IPD before, and recommended them here, but also I know there is a large group of opinion to go strictly oem.
Either way I want a new head, new pistons, liners, rings, plus looking at the cams and crank closely for damage. I know yiyito repairs turbos well from what I've heard, and mine only has 580 miles besides the damage hehe.
Rawze if you see this, I'd appreciate any input you have as well as Mr. Hagg, Unilevers, or others.
Thanks in advance.
RE: My Current cm871 situation - Signature620 - 05-29-2018
A failing exhaust gas pressure sensor or plugged pipe to it can contribute to a dropped valve.
Other factors can be simply the age of the cylinder head, valve seat wear, incorrect vgt/engine brake mapping, restriction in the exhaust.
I have only ever known 1 truck to have a McBee kit put through it and it ended up getting rebuilt with a Cummins kit 2 months later due to heavy oil consumption. There's nothing to say it wasn't assembled poorly the first time but I would probably never trust a non-genuine overhaul kit anyway.
RE: My Current cm871 situation - Rawze - 05-29-2018
(05-29-2018 )pearce trucking Wrote: ...
With that many past problems, I would suggest Letting Mr. Hag reman it the right way + any programming updated to latest revision and call it a day.
All i know is that i take care of my own truck, drive it right, and it simply makes me money without all those problems you describe. Only something that has had a history of abuse or something can be so bad.
RE: My Current cm871 situation - Unilevers - 05-30-2018
i second not using mcBee - that shits crap ive seen it with my own eyes.