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Is the 8.3 as prone to torching pistons or does the turbo keep it cool enough? Ken Sent from my SM-N910V using Tapatalk

It is our belief after killing three 250s that the real culprit is egt despite the often cited liner pitting. I think the issue much worse on the 939 trucks because the automatic allows lugging. I am hoping to gather more egt numbers from 939s but what I see on mine is scary given what we are...

Crap those are numbers I am seeing too. I have never let mine go above 1250 but I could see how it could get there fast. Considering your manifold is shorter I bet piston temp is about the same. That can't be good for them and I don't have the fuel up. Ever found a chart from Cummins...

Nice. I get 1200 easy with steady acceleration empty then i back out of it. My probe is in the cast iron one inch up from the lower joint where the pipe joins. Ken Sent from my SM-N910V using Tapatalk

Almost ready to dump everything we know on burning out the 250 Cummins motors but I am trying to gather one last bit of info. I am looking for pyro numbers from other members. Would love the temp and where your probe is either as measured from the center of the exh manifold or in relation to...

Boy I could be wrong but I am quite sure it is a one wire sender going only to the gauge varying just with voltage in relation to temperature. That motor is the latest in 1950's tec. An NHC 250 would run with fuel and a bumpstart, to my knowledge there are no controls you speak of on the motor...

Could be, can you bump the starter on an 813 while it is running? I wouldn't have thought they had the ability to sense when running. Just trust me, step on on strange electronic stuff is adjust all grounds from the battery box out. If it wasn't for the shutdown and the no start then I would...

To fix mine I had to replace the ground from the starter solinoid with a larger wire and replace the starter to frame ground. The issue didn't come up again after that. Never could see or feel anything wrong with the wires I changed but the issue resolved after. Ken Sent from my SM-N910V...

Is there a clutch depressed lockout on the 813? If not and it could be started in gear then I can't see anything in the high/low having a lockout. Wires rubbed through on linkage or body? When you follow the wire loom see any signs of crushing, rubbing or impact? Ken Sent from my SM-N910V...

Do the same for the starter motor and block. I literally had to add new lines to fix mine despite there being nothing obviously wrong with mine. Might be the motor is grounding through the starter and if that had a sketchy ground the fuel solinoid is snapping shut as a result. It is a serious...

Start by taking any ground staple loose you can find between motor and frame, body and frame and clean them. I had a phantom starting issue that only resolved itself when I put a larger ground between starter-motor-frame. Ken Sent from my SM-N910V using Tapatalk

It has been a hectic few weeks but yeah we still live. If you have no rod issues you might just be stuck with what I do, rotate the fronts to the rear and wait for the rears to grind flat again. I wasn't even aware the 5 ton kingpins could be adjusted. I do remember on member said his wear...

Brands change wear pattern I have found but I consider the Goodyear to be one I found that wears ok. With the truck off grab each of the joints in your hand and have someone shake the steering wheel back and forth. Any slop and you will feel it. I have never been able to keep the X and XL'S...

In every other civilian application I could find they have had the squirters in for cooling, I suspect it is a special Uncle Sam order for simplicity or cost savings. Manufacturer offers up a motor for 50/unit cheaper and the folks giving the contract the approval have no other agenda than cost...

Sorry about taking so long to update, been very hectic few weeks. Not the coolant, all the liners from #3 were spotless and 3 of the pistons showed signs of heat scoring. It was all EGTs. By all means get that green crap out of there and put the right stuff in. I don't care what the TM's...

I will know in a few weeks if it was something attacking the rubber. Ken

I will know in a few weeks if it was something attacking the rubber. Ken

Truck is back up and running. Used liner, piston, wristpin, rings and we reused the rod bearings that came out of it. Started instantly and after smoking for a bit burning the grease off now idles with no hint of white, black or blue smoke. Rolls a little dark grey when reved up, more than I...

Liner is out and looks brand new 100% no pitting. O-rings are a gummy mess and a large chunk was missing from the top one though it did not put water in the oil for over 48 hours while it sat. Injector tip looks fine. I am at a total loss as to what would cause this motor to eat a liner after...

Turns out it ate No 3 piston. From underneath the rest all look near perfect with no scoring. Going to pull the piston and liner Friday. If the liner shows signs of pitting then I am going to drop in a used liner, piston, rings, wristpin, o-rings and rod bearings from the motor we are...