c/diesel-mechanics

Tried cleaning injector tips with an old school ultrasonic bath from a pawn shop and it actually worked better than the new chemical soak.

After 30 minutes in that $75 machine, the carbon on a set of 6.7 Powerstroke injectors came off cleaner than a 4 hour dip in the latest solvent, which makes you wonder how many other old tools we've written off for the new shiny stuff.

The old way vs. the new way on diagnosing injector knock

Honestly, for years I'd just use a stethoscope and pull injector lines one by one on a running engine to find a bad injector. It was loud, messy, and you'd get soaked in fuel. About 3 years ago, the shop got a laptop with diagnostic software that can read cylinder contribution and injector correction values. Ngl, it was a game changer. Now I can usually pinpoint the problem cylinder in under 10 minutes without even getting my hands dirty. But some of the older guys here say you lose the 'feel' for the engine by just staring at a screen. What's your take, do you still do the line pull method or have you switched over to scan data full time?

Spent $400 on a 'universal' turbo rebuild kit that was missing half the parts

I was trying to save cash on a 6.0 Powerstroke job and the kit was a total mess... wrong gaskets, no thrust bearing. Some guys say cheap kits are fine if you know what you're doing, others say they're always junk. What's the worst aftermarket kit you've ever opened?

A conversation with a farmer about his old 4020 changed how I see 'simple' fixes

I was helping my neighbor, a guy named Frank, with his John Deere 4020 that wouldn't start. I was ready to dive into the injection pump, but he just asked if I'd checked the fuel shutoff solenoid. He said, 'I've run this thing for 40 years, and nine times out of ten, it's the little wire that wiggles loose.' Sure enough, the spade connector was barely hanging on. I've been so focused on the big, complex stuff that I skip the basic checks first. How often do you guys find the problem is something simple you almost missed?

A customer in Billings swore his 6.7 Powerstroke injectors were fine after a failed buzz test

He brought his truck in last Tuesday, complaining of a rough idle. I hooked up the scanner and ran a buzz test, which three injectors failed. When I told him, he got real quiet and said, 'Those are new, I put them in myself six months ago, they can't be bad.' He insisted I just clear the codes and send it. I showed him the live data, but he wouldn't budge. Ever had a customer refuse a clear diagnosis because they did the work themselves?

Had a 6.7 Powerstroke high pressure fuel pump grenade on me last Tuesday... $8500 later and I'm still mad about it.

Spent a full day chasing a coolant leak on a 6.7 Powerstroke that wasn't there

Had a 2015 F-250 in the shop with the owner saying it was losing coolant. Pressure tested it three times, checked every hose and clamp, even pulled the turbo to look at the up-pipe seals. Finally found the problem after 8 hours: the degas bottle cap was just weak and letting pressure bleed off slowly, making it look like a leak. It was a brand new Motorcraft cap too. Anyone else run into a bad new cap causing a phantom leak like that?

Talking to a retired marine engineer about injector timing

I was at a swap meet in Toledo last weekend and got chatting with this old guy, Gus, who used to work on ship diesels. He said, 'On the big two-strokes, we'd set the injectors by feel and sound more than the book, because the book was written for a clean engine in a shop.' I mean, idk, it made me think about how much I rely on the spec sheet for my Duramax work. Maybe I'm missing something by not listening more. Has anyone else had a mentor push them to trust their senses over the manual sometimes?

Just realized my old boss was right about using a torque wrench on injector lines

He told me 'you're leaving money on the table with those leaks' after a comeback, so I started torquing them to 35 ft-lbs exactly and my comeback rate on those jobs dropped to zero, what's one piece of shop criticism that actually made you better?

My brother-in-law said something about old trucks that got me thinking

We were looking at my 2002 F-250 in the driveway last weekend, and he asked why I keep fixing it instead of buying new. I told him it's simple and I know every part, but he said 'You're not just keeping a truck running, you're keeping a skill alive.' That hit different because he's not a mechanic, just a teacher. Made me realize a lot of what we do is about more than just turning wrenches. Anyone else feel like they're preserving something bigger when they work on the older stuff?

Showerthought: A talk with my dad about his old Detroit Diesel 8V71

He was over for dinner last night and we got onto his old truck, a '78 Freightliner with that screaming Jimmy in it. He said something that stuck with me: 'We used to fix things with a hammer, a wrench, and a prayer. Now you need a laptop just to say hello.' He wasn't even mad, just kinda tired. It hit different because I just spent three hours fighting with a CAN bus fault on a 2020 Cascadia, tracing wires and waiting for software updates. His generation could hear a miss and know which injector was lazy. I feel like I spend more time looking at a screen than listening to the engine. Anyone else feel like the 'mechanic' part of the job is getting buried under the 'technician' stuff?

Spent three days chasing a coolant leak on a 6.7 Powerstroke that was just a loose heater hose clamp

The truck was losing coolant overnight but only when cold. I pressure tested it, checked the usual spots like the oil cooler and degas bottle, and even pulled the turbo to look at the up-pipes. Finally found a tiny drip from the rear heater hose connection behind the engine block, a clamp that had just worked loose. Took about 30 seconds to tighten. Anyone else ever waste a ton of time on a problem that ended up being something stupid simple?

Vent: Tried a new injector cleaner on a 6.7 Powerstroke and it made things worse

Had a 2015 F-250 with a rough idle, so I ran a full bottle of that Rev-X cleaner through the fuel system. After about 50 miles, the truck started throwing a P0087 fuel rail pressure code and running even rougher. I think it might have loosened up a bunch of gunk that clogged the filters. Anyone have a go-to cleaner that actually works without causing more problems?

Got told my torque wrench habits were lazy and it stuck with me

Back when I was working at a fleet shop in Toledo, an old timer saw me torque a set of head bolts. I did the pattern right, but I was just pulling the wrench to the click and moving on. He said, 'You're just making noise. You gotta feel the bolt stretch, listen for the click, then hold it for a second. You're rushing the metal.' That phrase, 'rushing the metal,' really got to me. I started slowing down, feeling that final bit of tension settle, and holding the torque for a full two count before moving to the next bolt. It added maybe ten minutes to a head job, but I swear I had fewer come-backs for minor leaks. Anyone else have a small habit they changed that made a big difference in the long run?

Vent: I was torquing injector lines wrong for months

I kept getting minor leaks on a 6.7 Powerstroke rebuild, and a guy at the parts counter in Billings asked if I was using a crowsfoot. I was just using a standard wrench and not accounting for the offset, so my torque was way off. Anyone have a favorite crowsfoot set they use for tight spots?

Honestly, I'm seeing way more DEF system issues on trucks from the 2012-2015 era lately. Had three come into the shop last week alone.

My apprentice in Phoenix tried to skip the torque sequence on a Duramax head gasket last month.

He argued it was fine to just 'go by feel' because he'd done it on a small block Chevy, so now we're pulling the whole thing apart again to check for warping, and has anyone else had to drill this into a new guy's head?

Got schooled by a logging crew foreman in Oregon last month

Was out near Coos Bay fixing a snapped serpentine belt on a skidder. Dude walks over, watches me for a minute, and says 'You're gonna burn up the new one too if you don't check the idler pulley first.' He was right, the bearing was totally shot and had a wobble you could feel. I swapped the pulley, put the new belt on, and it's been running smooth for weeks now. Anyone else have a simple fix they missed that cost them a comeback?

TIL my stubbornness about a torque wrench nearly cost me a head gasket job

I had a 6.7 Powerstroke head gasket replacement lined up last week and faced a choice: trust my old clicker wrench I've used for a decade, or buy a new digital one. The old one felt fine, but I dropped the $220 on a new digital model after a buddy said his was off by 15 foot-pounds. Using it, I found my old wrench was under-torquing the head bolts by almost 10 pounds on the final pass. That could have been a comeback in a month. Has anyone else had a simple tool check save a big job?

Just got a 2005 Duramax with a seized injector to fire up after three days of fighting it.

I was about to pull the head when I finally got the stuck #7 injector to pop free by soaking it in a mix of ATF and acetone for 48 hours and using a slide hammer I borrowed from the shop down the street.

Unpopular opinion: the old school way of setting overheads on a 12-valve Cummins is a waste of time now

I used to spend a whole afternoon with a feeler gauge and a dial indicator, getting everything just right. After a rebuild on a '97 Dodge in the shop last month, I just used the go/no-go method with the new composite gasket. Took under an hour and it runs perfect. Anyone else just skip the full procedure on these older engines now?

I was torquing head bolts wrong for a decade until a CAT tech set me straight

I was rebuilding a 6.7 Powerstroke in my home shop last month and the head gasket blew after 500 miles. A friend brought over a CAT field service guy who watched me do the final torque sequence. He said, 'You're not letting the stretch bolts relax between stages, are you?' I had been going straight from the first angle to the second without the 15 minute wait. Has anyone else had a torque spec detail bite them like that?

Watching a tech at the Denver trade show insist on using only factory scan tools for everything changed how I handle diagnostics.

I saw him spend 45 minutes waiting for a proprietary software update to clear a basic fault code on a 6.7 Powerstroke that my aftermarket scanner could have fixed in 5, so when did we decide that paying for every single brand's system was the only 'right' way to work?

PSA: I keep seeing guys skip the torque step on injector hold-down bolts

Worked on three different rigs this month where someone just cranked them down by feel. Every single one had a small fuel leak that ruined the gasket. You need a good inch-pound wrench and the factory spec, which for a 6.7 Powerstroke is 120 inch-pounds in two steps. It's not hard, but it makes a huge difference in how long the repair lasts. Anyone else run into this or have a favorite torque wrench for small stuff?

I finally listened to my old boss about the coolant filter on a 6.7 Powerstroke

He told me to change it every other oil change, not just when the light came on. I blew it off for a while, thinking it was just him being picky. Last month, my truck started running hot and I found the filter housing full of casting sand and junk. Now I do it on schedule. Anyone else have a simple tip they ignored that bit them later?