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I've been running the overheads on several mp8's lately, 2008 to 2012 models. I've noticed on the older trucks the lash spec is on the label on the valve cover, 3.5mm. It's not shown on the 12's. Someone told me the lash was updated to 2.5mm. IF this is true is it just for later models or for 08's as well.

Sometime after making an aftertreatment repair and run a manual regen, The lightning bolt remains on and guard dog states Evaluating DEF quality engine in derate 5 mph limit removed. All dtc's clear out except, ECM-4094-1. stating dtc has to be stored 400 days by law and to put back in service, in a nutshell. normally if the repair took care of the problem the warning would go away in a few hundred miles, and sometimes not, and I'd have to dig deeper. Anyway I'd like to know if there is any way to turn the lightning bolt off and stop the "Evaluating" warning from popping up. Some drivers won't take the trucks out in this condition.

not sure about the rpm but it seemed to be about 15 or so. every time i shifted it would pull normal for a second then no acceleration. grab another gear and the same thing. Feels like a gas engine with an ignition breakdown.

I finally got someone to make the call (I wasn't going make the call) to replace the cups and injectors. smoothed the problem right out. That was the first one I seen with this problem. Now off to fix the other two.

Well I got the exhaust leak taken care of but the problem is still there.

I did find oil in the lower connector to the ecu. I cleaned it all with contact cleaner but didnt help. I didnt know about a problem with the harness connector to the pressure sensor..the one on top of the intake manifold just back from where MP8 is embossed on the side. thats the only one I see. On another truck I found a very bad exhaust in the J shaped pipe from the egr to the cooler, maybe when it pressures up it could be blowing boost back that way and leaking. ought to have the gaskets and clamps today. I'll let yall know if it helps.

Could someone post a pic of the wiring diagram for the fifth wheel? I've traced the switched ground from the switch to the vecu and it's good. I would like to know what pin the switched ground is in the bulkhead connector. No switched ground getting back to the air actuator.

Thats pretty much what guided diagnostics told me. thanks I need to get a book like that though

Ok, SPN 1127 engine turbocharger boost pressure FMI 18 and 10

Regening truck, inlet and outlet temps nearly 900f. I noticed the green light wasn't on for the bypass valve. On the side of the scree it says " the drv should be active during regeneration. Is this normal?

some do and some don't but there all inactive. I cleared all the codes on one and let a fella go drive it. He said he could only get 50mph before turning around and coming back. When I checked it it only had three boost codes. I haven't had any formal training on these trucks, I was an import dealer auto tech for 25 years prior. I've been learning these trucks by the seat of my pants for the last 6 years. I have no manuals and have no idea what the code letters mean with the dtc's. I sure was hoping one of you guys would say its this or that. I drove one around the yard yesterday and it felt like the boost was "dumping" then surging back, if that makes any sense. Maybe like the bypass valve decided to open up just for shits and giggles.

I wrote those code numbers down but i think I through the paper away. This is like a plague, every day I'm getting another tractor or two. Today I got to ride in one on the road, it seemed ok at times and then fall on its face while going through the gears. There is a service bulletin to check the pin connectors in the round VGT harness connector. I have done several of those but not in the last two years. the drivers complained of surging low power ant times. Those tractors were easy to troubleshoot, with key on engine off you could wiggle the VGT harness connector and you could hear the VGT motor run. When running the VGT tests on the tractors I'm working on now the sweep test goes from 0 to 100 with 40 effort hot. I assume there is a sensor and thats not just reading what the the VGT is suppose to be doing. But now that I think about it we had a few older, like 08 models that the inner part of the turbo gasket fell down into the turbo and stopped the VGT from doing a full sweep. So I guess there is a sensor. This is an oilfield fleet of abused and neglected tractors that has a lot of idling time on them. example.. 4 years old truck with 9800 miles and 6800 hours. Our company is hanging on by the skin of their teeth with this downturn in the oilfield right now o I just cant go throwing new turbos at the trucks and that not be the problem. Also currently I am the only mechanic addressing the technical issues with these trucks ranging from 08 to 2013 models, and I stay covered up with SCR problems. I need some help!

Update...After inspecting the innards of the tranny without tearing it down we reinstalled it. The splitter works fine sitting still, with the switch up it is in high, but when you shift from 5th to 6th driving it goes to neutral. Its a mind boggleing thing.

Ok, thats what I thought on the cooler. Anyway I ran the VGT function test and it seemed to work fine. The vgt effort never got over 60 or so. I did replace the boost sensor but it did no good. I dont have a cdl so I can't take it out and drive it myself. I can't get much boost pressure by gunning it in the shop but when I do it gets about 7 or 8 psi .I thinking I would have to be a pretty bad leak to set a dtc and have lack of power. I've had trucks come in with the oring blown out of the air cooler line at the cooler and it was whistling and didn't set a code or show any lack of power.

My shop calls popping a "15 minute job" Also I'm not sure what MackPro is referring to as an after cooler?

I found it! I had a helper check the fuses. It turned out being fuse fu10, comm conn radio fuse. It showed good with a test light but it blew hard and pushed the element againt the terminal at the top.

Thanks but all of our fleet are the same, no data loggers. I had just hooked up to the unit a few days ago and everything wS fine. Can't connect to the bendix program either. I thought it may have been my cord, but it works on other tractors

I've got scr problems but when I connect my Vocom communication tool to the connector the engine light doesn't light on the Vocim doesn't light up, so I can't communicate with tech tool. I've checked fuses and hooked to another truck and it works fine. I've also looked at the pins in the data link connector and they look good. I've checked fuses. Any thoughts?

I don't know why but these various boost pressure dtc's and complaints of intermittent pow loss have been coming in lately. This is an oilfield fleet so its hard to get feedback from the drivers, there's no telling who will be driving any truck at any time. Anyway If no boost leaks are detected, the EGR seems to be working ok and VGT test runs good would you say I have a boost (intake) pressure sensor that acting up intermittently? Or what have you guys been seeing? Thanks in advance.

It's not the shaft that concerns me it's the play in the gear on the transmission side. capturedvideo.MOV

Not sure if it would pull itself. The guy who checked it out is on vacation. I called him and he said the truck was towed in from the field. He don't know why but someone tried to adjust the clutch, the pedal was almost all free play . He adjusted the clutch to where it felt normal, reinstalled the driveshaft when he went to pull away he said it lugged the engine down and chattered loudly. What I saw when inspecting the transmission is, I pulled the input housing, the gear that's held on by a spiral ring had play in all directions. It would move up and down and would rock back and forth while holding the shaft still. I have gave the clutch a good looking over. This is a remack remanufactured transmission with very few miles on it capturedvideo.MOV

I wish I had more to go on but, I Just got a 2010 Granate Maxitorque dumped on me with the tranny already on the floor. I got four different stories about what was wrong with it. I finally got in touch with the fella that pulled it down and he said " it had all kids of chattering noise in the tranny when coming off the clutch." He also said it had fine metal in the oil that looked like metalic paint. I pulled both top covers and inspected and worked all the gears. saw no broke parts. But what I did find was the input shaft gear has a lot of slack or backlash verus the input shaft, meaning if I hold the input shaft the gear will rock back and fourth about .020. I pulled the spiral ring that holds the gear to the input shaft, pulled the gear off and inspected the cogs. to my surprise they didnt look worn but the lock ring groove had pastie fine metal in the area where the ring goes. I have repaired automotive manual transmissions but nothing like this. I really can't see there being any play in the input haft gear to the input shaft. All the trannys I worked on the the shaft and the gear are one piece. I have also ispected the clutch. It appears to be ok. Thanks in advance for any help!

I have an 09 mp8 that reads about 230deg oil temp cruising under load. coolant temp normal. Is there anything other than the sensor in the pan that would give me this reading? Thanks

I could blow through the hydrocarbon dosing nozzle. we got a new one and it took care of the problem. Thanks

found it. Bad sensor and it was tagged. Thanks