/r/DieselTechs
Where diesel techs help other diesel techs with questions, advice, how-tos, and - sometimes - sweet, sweet karma.
DieselTechs is a resource for those who are currently employed in the diesel maintenance field. This subreddit's mission is to become the best place for technicians to help each other with such things as:
rare, puzzling, problems that can't be diagnosed properly. e.g.; "anyone ever run into this before?"
advice on resources to help us further our careers. eg; "Can anyone give me advice on ASE certs?"
Help with job hunts. eg; "Our shop can't fill a position, who lives in Oakland?" or "I'm moving to Oakland, anyone know who's hiring?"
This definitely IS the place for medium and heavy duty techs. we want all of you: Marine! Truck! Transit! Coach! Generators! Heavy Equipment! We also encourage questions regarding support systems, too - e.g.; air brakes, outdrives, transmissions, whatever!
SO MANY RULES!?!?! This is to prevent traffic from leaving other, awesome, subs out there! Hey, check some out:
At this time, no restrictions will be placed on who or what will be submitted, but posts should be from a current diesel technician with a question. Once again, there are a lot of other subreddits out there for "check out my rig!" or "Lol, look what this customer did to his turbo!" or "which is better Cummins or Powerstroke?" so please submit them to the appropriate places. Flair and Verification coming soon.
/r/DieselTechs
19,951 Subscribers
Volvo, Mack.
I don't know if this can help anyone in the group as most posts I see, seem to be on freightliner or internationals. I am a licensed tech at a Volvo Mack dealership. My specialty is transmissions, more particularly the I-shift, or M-drive. Any questions, feel free to ask. I hope I can help.
03:43 UTC
Help!
Let me preface with saying this is probably a dumb question, especially in a forum full of full time techs. I just replaced the injectors in my 5.9 cummins and am reassembling right now. There is a significant amount of play on my furthest back rocker (cylinder 6). How bad is this? Is it just a valve adjustment? I will include a video as well. Please give me any and all info! Thank you in advance.
01:57 UTC
Coolant in crank case
16 peterbilt 579 Cummins isx. Losing a gallon of coolant a day. Noticed water drops coming out of crank case breather tube. Pulled the cover and water dumped out. Pulled the oil dipstick and oil is very clean inside the motor even after running the truck and getting it all mixed up before checking. What can cause coolant in the crank case but not in the motor. Wondering if there is any scenario that doesn’t involve an over haul.
21:15 UTC
EGR Saturday's
Quick 6.7 Cummins cooler, power and telecom fleet mechanic.
18:31 UTC
How do you welcome a new apprentice to your shop?
17:24 UTC
How much is too much to remove from a flywheel resurface job?
I took off a flywheel on a MX-13 and the machine shop said they took .03 or 30 thousandths.
16:44 UTC
My toolbox 2 weeks into my first internship
I'm working at a fleet shop and so far I love working. I have so much more to buy but anything you guys see I don't have that I would need really badly?
07:50 UTC
How Do California Trucks Keep Getting Away With Deletes When the Gestapo is After Them?
I recently spent a day dining outdoors and then relaxing in a park.
Being who I am I noticed all the diesel pickups slowly driving by on the county road, lots sound straight piped.
Heavy trucks out on the state highway, especially hay and bullracks, straight piped also.
Now in my world, these would be throwing codes for DPF problems, being as how the DPF does not seem to even exist on most of them.
Pickups need to get smogged every 2 years, and heavy trucks are annual I think.
How do they get away with any of this?
05:02 UTC
Lighting issue trash trucks
Hey guys I’m back again with yet another issue. Working on a truck currently and it’s got no clearance lights unless the the parking brake is applied or the foot brake is pressed. We don’t have any diagrams for some unknown reason and I’ve been asking the supervisor for a while to get them. Any ideas on how I can find them? Along with the clearance lights there is no brake lights.
04:11 UTC
Coming down like tears for fear!
02:46 UTC
Impact Sockets
Looking at getting some impact sockets as get ready for an apprenticeship, debating between tekton and capri sockets. Any of y’all have experience with both brands? Or any other recommendations?
23:04 UTC
A real crazy shift pattern ? Say hello to Minneapolis Moline tractors !
How's this for a bad shift pattern ? Non synchromesh, so get those RPMs right ! LOL.
We had an 880 that we used for powering an auger, etc. Didn't drive it much. Was always a pain shifting that thing to get to road gear to go from one location to another. As long as you stayed in one "range" it wasn't bad. Most times could just use 3-4-6 on the road. But sometimes you needed 2-3-4-5-6. 2nd to 3rd wasn't bad if you stared at the diagram but 4-5-6 was tricky.
It probably wouldn't be bad if you drove the thing all the time. We only used it in harvest and most of what it did was stationary PTO work.
22:32 UTC
Smallest sleeved diesel engine ?
What is the smallest diesel engine that has replaceable wet bore sleeves ?
466 International and its smaller sibblings ? 360, 404, 414 ?
53 and 71 series Detroits.
What else ? Anything smaller ?
22:16 UTC
Rush Peterbilt Employment
Good evening, fellow technicians
I'm considering starting my diesel mechanic career at Rush Peterbilt in Denver, Colorado, and was wondering if anyone here has experience with the company or knows what it's like to work there. I'd love to hear any insights on the work environment, training opportunities, or growth potential.
Thanks in advance for any input or advice.
21:39 UTC
Flywheel is smooth, no hot spots, I’ve tried desperately to get it off to resurface it but can’t. Help.
Working on a MX-13 Paccar clutch job. My flywheel is of course used. I tossed everything I had at the flywheel bolts and I couldn’t get them off. The torque specs on these are apparently kind of high.
I am going to be replacing the clutch like that. The flywheel has no hot spots it is concave where the other pads were rubbing in at but not a giant pit.
I really really did try hard to remove those bolts. But I can’t. I tried breaker bars, and a 3/4in Milwaukee impact. I usually take of my lug nuts with it and this time no success.
What’s the worst that can happen? What should I do?
A. Keep trying and break those bolts off one way or another it’s not worth doing it like that?
B. You should be okay? Not recommended but should be fine?
20:47 UTC
Anyone ever bought Nexiq from Aliexpres?
20:27 UTC
Rail pressure problems
Hi, im totally stumped with a problem im having and dont know who to ask anymore, so im hoping this might be a good group to ask. I assume you arent maybe familiar with this exact model but most of the systems work simmilar way so why not give it a shot. The engine in problem is the bmw m57. The first iteration with 184hp and the cp1 common rail pump, ran by a bosch edc15
In tank pump replaced
Supply pump under the drivers footwell replaced with oem pierburg
Hpfp replaced with bosch reman unit including a new bosch regulator
All 6 injectors replaced with bosch ones
Rail sensor replaced with oem bmw one
Filter new, no leaks or anything out of the ordinary.
Tried different ecu
Im getting a bmw code 4496 which basically says low rail pressure in correlation with engine rpm.
The code shows up when the car cuts out completely which is a fail safe to protect the hpfp. What bugs me is (besides thousands of euros spent to no awail) the code says the pressure is like 100bar or lower even though when i watch the live data its i guess close to target pressure, about 800bar+/3000rpm. It also says pressupply pressure is 0.05bar, which is just impossible, because it also says 4bar in live data before it cuts out, and needs about 30s to fall to 1bar after pumps shut off.
The car then has a hard time starting again, it doesnt need a lot of cranking, it just needs to sit for about 3 min, and then it fires normally, but when it does, it idles normally. It always cuts out at about 3k rpm, regardless of the load/boost.
One other thing to note, the car is a swap (320d to 330d). A whole donor car was used, it worked completely fine in the other car, the whole fuel system which is really complicated was transferred over in one piece so no errors could occur. All the routing has been checked over 100 times using pictures taken from the old car..
Any pointers would be appreciated.
17:52 UTC
Deere 4045TF280 leaking at front crank seal(3rd)
I have a deer 4045tf280 that we replaced a timing cover gasket on. I’m on my third front main seal, and they won’t stop leaking. I am using the deere installation tool, smooth, steady, easy, not my first rodeo. Kind of stumped here. Any ideas? I have not replaced the crank pulley yet.
15:02 UTC
This'll cost a bit of money lol
Little backstory, the company I work for bought a smaller garbage company. This freightliner fried the MCM. Replaced it and now it constantly thinks it needs a regen. Judging by this pic, any guesses as to why? 😂😉
13:33 UTC
Nice Friday project
Rebuild this valve body. Actually relieved to do something somewhat mindless for once even though it's annoying 😂
13:30 UTC
Advice on power loss only on highway with a VERY specific symptom!
I cannot for the life of me work this one out!
Australian spec 2018 MQ Triton (2.4L Diesel Auto, no mods). 117,000km.
Drives around suburbs no problem. As soon as I pull onto the highway, I can predict that at almost EXACTLY 6km (or perhaps the "time" equivalent), the engine suddenly loses power in a jerky on/off manner, and tacho wavers erratically, nearly stalls. NO CODES (Not a professional mechanic, but I have a scan tool).
Motor splutters, I start to pull over, nearly dies, after 20 seconds to a minute, power returns and everything back to normal. Live data shows actual fuel pressure dropping below target fuel pressure at time of rough running.
SO FAR, replaced SCV and Fuel Filter Housing (and filter). No change. Tried same test with fuel cap off (to rule out tank vacuum), no change.
Any ideas? This issue with the very specific distance (perhaps time?) before failure feels like a really strong hint, but so far I haven't been able to work it out or find any other example on google.
Any help, or suggestions for further diagnostics, appreciated.
Matthew
11:44 UTC
Freightliner MT45 Stalling When Coming To A Stop
I work for a Fedex contractor, and we have several Freightliner Mt45 P700 vans. All have Cummins 5.9’s and Allison AT545’s. Every one has an issue with the trucks randomly cutting off when coming to a stop and/or when turning.
Basically, when we slow down, we feel the engine sputter then eventually die, alongside a buzzing noise comes on. The trucks will just crank and crank, won’t start unless we mash the gas pedal to the floor. Even then, they struggle to start with the gas pedal, but eventually do restart. Our mechanic is an idiot and can’t seem to figure this out, so I’m on here to hopefully get some pointers.
01:47 UTC
Mobile Repair
What are the most common mobile repairs people do or are requested by customers?
23:53 UTC
Deutz 2.9 l4 codes
Hello, I’m looking for some input on the engine that seems to love throwing codes that is in my 2018 Vermeer wood chipper. I’ve been having an ongoing issue for around 2 years with the code SPN 523470 fmi 14. In this time, the shop I take it to and the duetz dealer have together replaced the plug going into the metering valve, the metering valve, the prv, multiple fuel filters and the entire wiring harness. We also dropped the fuel tank and cleaned it out. We still continue to get the code and have to keep getting the ecm flashed to stop it for a couple months at a time. Any and all input or ideas would be great. It was shooting off SPN 523470 FMI 7 today. Thanks for any help!
23:08 UTC
Poor bastard was one day from retirement.
2018 w/ x15, Last day as a rental unit before it goes up for sale and the customer got in an accident. This is why we cant have nice shit.
22:58 UTC
Tripac evolution apu
Engine runs fine for a few minutes then it shuts off Code 20 engine failed to start Also starter keeps trying to engage even though the engine is on, rpm reads fine. Any suggestions ?
22:27 UTC