c/diesel-mechanics

That Monday a bird nest killed a $6,000 engine rebuild in 20 minutes

I was flushing coolant on a 2015 Freightliner Cascadia last week and a pile of straw and twigs came out stuck to the thermostat housing. Turns out a bird had built a nest right above the fan shroud and it got sucked into the radiator during a highway run. Has anyone else found random stuff lodged in their cooling system after a long idle period?

Tried a cheap injector puller from Harbor Freight and it snapped on the third truck

I thought I was saving 80 bucks going with the Pittsburgh puller instead of the OTC one. Third time using it on a 6.0 Powerstroke and the threads just gave out halfway through pulling an injector. Now I got a stuck injector and a broken tool sitting in a bay waiting for my buddy to bring his Snap-on over tomorrow. Learned my lesson about trusting those cheap sets for anything that takes real torque. Anybody else have a horror story from budget tools on heavy work?

That time in Billings I learned the hard way about injector cups

Got a call to do injectors on a 6.0 at a ranch outside Billings last November. Everything was going fine until I pulled the #3 injector and the cup came out with it. My heart sank because I knew I didn't have the right puller tool on my truck. Ended up having to drive 45 minutes back into town to borrow a kit from a friend at Cummins of Montana. Now I always keep a spare cup tool set in my box just for those older Powerstrokes. Has anyone else had a cup come loose like that or was I just unlucky?

Framing vs. Rotella for my old 7.3... not even close

I swapped from Rotella 15w-40 to Shell Rotella T6 full synthetic in my 2002 F-350 7.3 Powerstroke about 6 months ago. The old dino oil had it sounding a little clattery on cold starts in the winter here in Michigan. After the swap it fires up way quieter and seems to hold oil pressure better when it's idling hot. Has anyone else noticed a big difference going synthetic on a high mileage motor?

Finally gave in and tried using starter fluid on a cold Detroit Diesel

I always swore it was a hack that would wreck your rings, but after fighting a 6V92 for 45 minutes at 6am in January, I hit it with a half-second shot and she fired right up. Has anyone else stopped being stubborn about this and actually seen any real damage from occasional use?

Heard a parts guy say injectors are just expensive fuses and honestly that explains a lot

Guy at the counter in Omaha told me that when I brought in a dead #5 injector from a 6.7 Powerstroke, said 9 times out of 10 it's a wiring or driver issue not the injector itself, anyone else find that true with these high pressure common rails?

Talked to an old fleet mechanic in Tulsa and he said my torque wrench was just a suggestion tool

He told me he never uses a torque wrench on lug nuts, just goes by feel after 40 years, and now I'm wondering if I'm wasting time or if he's just lucky nothing's snapped off on him yet, anyone else run into old timers who refuse to torque stuff?

Why does nobody talk about the $300 mistake of buying cheap injectors online

Picked up a set of reman injectors off eBay for my 6.0 Powerstroke back in June. Thought I was saving big, you know, compared to the dealer price. Three weeks later, truck was running rough again, white smoke everywhere. Took them to a local shop in Austin and the guy said they were basically rebuilt with junk internals. Lost the $300 and had to buy a proper set. Anyone else get burned on budget parts that just cost you more in the end?

Blew a turbo at 2am on I-80 in Nebraska

Was hauling cattle from Omaha to Cheyenne when I heard that whistling sound turn into a screech. Pulled over and found oil all over the exhaust side, had to limp 30 miles to a truck stop and swap it in the parking lot with a flashlight. Anyone else kept a spare turbo onboard for emergencies?

Old timer vs modern diagnostics debate got me thinking

I had a conversation at the TA in Flagstaff last week with a guy who's been turning wrenches since the 70s. He swears by the old school methods like using a stethoscope and timing light instead of plugging in a laptop. I told him I get results faster with my scanner and live data. He said, "You're just reading codes, not understanding the engine." That actually hit me because half the time I'm swapping parts based on what the computer says, not what I feel or hear. But on the other hand, these new engines are so computer controlled that you kind of need the digital stuff. So I'm wondering, which side do you guys lean on when a truck comes in with a weird driveability issue?

Tried the old school hammer method on a seized injector after 15 years of using pullers

Ive been doing this since 2008 and always grabbed my slide hammer for stuck injectors. Last week I was on a 6.0 Powerstroke out in Tucson where the puller just wouldnt grip. Old timer I was working with said just tap it sideways with a brass hammer and work it free. I told him he was crazy but I gave it a shot after I wasted an hour with the puller. Thing popped right out in like 3 minutes. Now I feel dumb for fighting with that tool for so many years. Any of you guys still use the old hammer method or am I just late to the party?

The moment I learned injector timing is everything - and why I was dead wrong for 5 years

I used to just slap injectors in and hope for the best with timing. Then a guy at a shop in Denver pointed out I was missing by 3 degrees on a 6.7 Powerstroke, and the thing ran smooth for the first time ever. He showed me the smoke test vs a proper timing light - night and day difference. Have you guys ever had to eat crow on a basic thing you thought you had down?

Used to hate electronic injectors till I saw a buddy's data log

I was always old school mechanical pump guy, thought all this electronic stuff was just more crap to break. Then my buddy showed me a scan from his laptop on a 6.7 Powerstroke that had a dead miss. He pulled up the cylinder contribution test and saw #4 was at like 80% below the others. 20 minutes later he had a new injector in and the truck ran perfect. That data made me realize I was just being stubborn. Anyone else change their mind about something after seeing actual numbers?

Hit 500,000 miles on a 6.7 Cummins this morning and it still purrs like new

The old heads say half a million is nothing on these but the newer guys think I'm crazy for keeping a truck that long, so what's your cutoff for when an engine is just too worn to trust on a long haul or does mileage even matter anymore?

Warning: dont trust those cheap injector pullers from amazon

I used to always just rent the fancy OTC puller from oreillys for 20 bucks. Then i bought a $35 kit off amazon to save a trip and it broke on the third injector. That was in january on a 6.0 powerstroke in a gravel lot near madison. Has anyone else had luck with a specific brand that wont bend under heavy rust?

Old timer told me to run my DT466 on rotella 15w40 year round even in winter. Called him crazy. Truck wouldn't start at 8 degrees last january in nebraska.

The debate about using infrared heat guns vs. sticking a thermocouple in the exhaust manifold for checking cylinder temps on a 6.7 Powerstroke has me wondering if the old school way is still the most reliable way to catch a lazy injector early, or if I'm just set in my ways because I've been doing it that way since 2012 and the new tools feel like guessing games to me, what do you guys think?

I got into an argument with a younger tech last week because he swore the infrared gun was faster and just as accurate, but I pointed out that on my last EGR cooler delete job the thermocouple caught a 60 degree difference between cylinders 2 and 3 that the gun totally missed because it was reading surface temps from the heat wrap, and now I'm second guessing myself because maybe I just didn't use the gun right, so has anyone else run into this situation where the new method missed something obvious?

Stopped at a little repair shop in west Texas and saw something I hadn't thought about in years.

I was driving through Sweetwater last Tuesday and pulled over at this old diesel shop near the highway to grab a filter. The guy there had a whole wall of rebuilt injector pumps from the 90s just sitting on shelves, labeled by hand with masking tape. It got me thinking about how much less disposable those old engines felt compared to the emissions stuff we deal with now. You ever run across a shop that still works on the mechanical stuff exclusively and wonder how they stay afloat?

Old timer told me to never use starting fluid on a diesel. Ignored him and blew a glow plug out the side of the head last Tuesday.

Honestly, I figured a little shot wouldn't hurt on a cold 7.3L. Now I'm pulling the head and looking at a $1800 repair bill just because I didn't listen. Anyone else learn that lesson the hard way?

Walked into an old fleet shop in Ohio last week and felt like I time traveled

I was picking up a used air compressor from a retiring mechanic near Dayton. He still had a 1970s era Cummins NTC 350 on a stand covered in grime, the block was cracked but he knew every inch of it. Made me realize how much of this trade is gone now, nobody schools you on those mechanical injectors anymore. Any of you guys still work on old NTCs or are they all just museum pieces now?

Showerthought: Realized I'd been torquing head bolts wrong for 10 years

Was helping a buddy with a 6.0 Powerstroke at his shop in Tulsa last month. He watched me do my usual 3-step pattern and just shook his head. Turns out I was skipping the final 90-degree turn on the last step this whole time. No wonder I had a couple gaskets fail early on me. Anyone else find out they'd been doing some basic step wrong for years without knowing?

Switched to synthetic oil in my old Cummins and I'm eating crow now

Always ran conventional Rotella in my 12-valve because that's what the old guys said to do. After 320k miles the overhead started clattering cold, so I finally caved and went full synthetic 5w-40. Quieted down in 2 days and the oil analysis came back cleaner than any winter batch I've had. Anyone else stubborn about this or am I late to the party?

Always blasted injectors with carb cleaner until a guy stopped me

I used to spray carb cleaner straight into diesel injectors thinking it was the best way to clean them. Then a retired mechanic at a shop in Tulsa told me it strips the internal coating and ruins the spray pattern after about 50 hours of run time. Has anyone else been doing something simple wrong for years and only found out by accident?

Took me 3 years to realize I was bleeding injector return lines wrong

I've been a diesel mechanic for about 8 years now, went independent about 2 years ago. Last month I was working on a 2015 Cummins ISX at my shop here in Billings, changing out injectors on a #6 cylinder that was misfiring. After I buttoned everything up, I went to prime the system and fuel started pouring out of the return line banjo fitting. I'd always just tightened those down snug and called it good. Turns out I was supposed to torque them to spec every time - about 18 ft-lbs on that model - because the copper washers deform and seal only once. My old boss at the dealer never mentioned it, I just assumed snug was enough. The tip off was a puddle of diesel on my floor that told me real quick I'd been doing this half-assed for years. How many of you guys actually torque return line fittings or is it just me that missed this memo?

The big debate - injector cleaning vs replacement on high mileage trucks

I keep seeing guys on here swear by pulling injectors and soaking them in cleaner to save money. But I have a 2005 Cummins with 350k miles and the shop said replacement is the only real fix. I soaked mine for 48 hours in a $30 kit and the return flow numbers barely changed. On the other hand a buddy did a hot tank clean on his 7.3 Powerstroke and it ran better for another 40k miles. So is soaking just a bandaid or does it actually work if you do it right? What have you guys seen on trucks over 200k miles?