c/diesel-mechanics

Am I the only one who sees guys skip the torque sequence on a head gasket?

I watched a shop in Boise just crank down the center bolts first on a 6.7 Powerstroke, which is a sure way to warp the head. They said it 'saved ten minutes' but that motor came back with a leak after two weeks. How do you make sure new helpers get this right every single time?

Can we talk about the time a coolant hose blew on a Detroit 60 series in the middle of a Wyoming blizzard

I was 50 miles from the nearest town with a 3/4 inch split in the upper radiator hose, so I cut a section out of my leather belt, wrapped it tight with three hose clamps I had in my box, and limped the rig to a truck stop where I could do a real fix.

Vent: I bought a $300 'universal' diesel diagnostic scanner that couldn't even pull codes from a 2015 Duramax.

Has anyone else found a scanner that actually works across different heavy-duty brands without needing a dozen different subscriptions?

Just realized my shop has done 500 DEF system cleans in the last year

That number really hit me because we only did maybe 150 the year before. It feels like every other truck that comes in now has a clogged injector or a fouled sensor. Has anyone else seen this kind of jump in DEF work?

I was checking valve lash on a 6.7 Powerstroke for years before a foreman pointed out my mistake

I always set them cold, but he saw me doing it and said, 'You know the book says hot, right? You're off by a few thou.' I had the manual in my box the whole time and just never looked. How many of you guys actually run them up to temp before you adjust, or is cold okay for a quick check?

I bought a cheap knockoff DPF cleaning kit for $150... big mistake

Tried to clean a clogged filter on a 6.7 Powerstroke myself to save shop time, but the cheap chemicals just made a mess and didn't clear the soot at all. Ended up having to replace the whole DPF unit, which cost me over $2,000 in parts and labor I could have avoided. Has anyone found a cleaning method that actually works, or is sending it out the only real fix?

Just realized I blew over $500 on a 'universal' turbo rebuild kit that didn't fit anything

Back when I was starting out, I got a deal on a kit from a sketchy online seller for a 6.0 Powerstroke job. The ad said it was for 'most common turbos' but the bearings were the wrong size and the gasket set was missing three key seals. I wasted a whole Saturday trying to make it work before giving up and buying the right parts from a real supplier. Ended up costing me the kit money plus the labor time I lost. Has anyone else gotten burned by those too-good-to-be-true parts ads? What's your go-to brand for turbo stuff now?

Can we talk about the cheap aftermarket turbo rebuild kits on eBay?

I put a $150 kit from some no-name seller into a 6.7 Powerstroke last month and it lasted about 300 miles before the bearings went. The wastegate actuator was junk right out of the box. Anyone have a go-to brand for these that won't cost a fortune but actually holds up?

Hot take: I used to think those fuel additive tests were all marketing, but one changed my mind

I had a 2005 Duramax come into the shop last month with a real rough idle and some power loss. The owner swore by a specific cetane booster he'd been using for years, but I was sure it was an injector issue. We ran the tests, and everything checked out fine on the mechanical side. Just to prove a point, I told him to run a tank without the additive. The truck came back a week later running noticeably worse. We put the additive back in, and within half a tank it smoothed right out. I guess the fuel quality in our area has dropped more than I thought. Has anyone else seen a case where an additive actually made a clear, measurable difference on an older engine?

Rant: My cheap infrared temp gun gave me a false reading on a 6.7 Powerstroke

I was checking for a hot spot on an EGR cooler last Tuesday, using a $40 infrared thermometer I grabbed from the parts store. It showed a 40 degree difference between two spots that should have been the same. I almost started pulling the cooler based on that. Then I borrowed my buddy's Fluke unit and the temps were dead even. Learned the hard way that the cheap ones can't handle shiny metal surfaces well at all. Has anyone found a decent mid-range temp gun that actually works on manifolds and turbos?

Just hit 30,000 psi on a fuel system test and it scared me straight

I was checking a Duramax injector line with a new gauge from the shop, figured it would tap out around 25k like usual. When the needle blew past that and settled at 30,000, my heart skipped a beat. That's way over spec and means the pressure relief valve is probably stuck or the pump is about to grenade. I shut it down right there before something let go. Has anyone else seen a common rail system hold that kind of crazy pressure without an immediate failure?

A guy at the truck stop in Flagstaff told me I was overthinking injector timing

I was setting the timing on a 6.7 Powerstroke by the book, using a dial indicator and getting it perfect. This old timer watched me for a minute and said, 'You're chasing a ghost. That motor wants to be a hair advanced, not dead on spec.' I fought him on it, but tried it his way on the next one. The truck ran smoother and had less haze at idle. Anyone else find the factory specs aren't always the sweet spot for a running engine?

My uncle swore by using a propane torch to heat a stuck injector, and it actually worked on a 6.7 Powerstroke last month.

He's been a fleet mechanic for 30 years, and I was skeptical. We had one injector that just wouldn't budge after trying the puller and soaking it. He said 'just a little heat on the body, not the tip, for about 30 seconds.' I was worried about damaging the head, but we wrapped the surrounding area in wet rags. Gave it a shot, and it came right out with a solid tug. I'd always avoided heat on fuel systems. Anyone have a different trick for a really stubborn one, or is this a bad idea on certain engines?

Choosing to rebuild a 6.7 Powerstroke injector instead of buying new saved my shop $800

Had a 2015 F-250 in the bay with a dead injector on cylinder 3. The customer was quoted $1200 for a new OEM unit. I pulled it, sent it to a local rebuilder in Toledo, and got it back for $400 with a one-year warranty. Truck runs perfect now, no codes after 500 miles. When does it make sense for you guys to rebuild versus replace on these newer high-pressure systems?

Pro tip: I swapped to a 5W-40 synthetic in an old 7.3 Powerstroke and it got louder

My '96 F-250 with the 7.3 was always a bit noisy, but I figured a full synthetic Rotella T6 might quiet it down. After the oil change, the injector clatter actually seemed more pronounced for the first hundred miles or so. It smoothed out after that, but it taught me that switching oil weights on high-mileage engines can have some weird break-in effects. Has anyone else in the Midwest run into this with an older diesel after an oil change?

A veteran tech in Boise changed how I see glow plug testing

I was sure a bad glow plug would always show infinite resistance on a meter. Then, at a shop in Boise, a tech named Carl showed me one that read 0.6 ohms cold but would short internally once it got hot. He said, 'You can't trust the first check, you have to watch it under load.' Now I always do a running voltage drop test after a cold check. Has anyone else found a glow plug that tested okay cold but failed when warm?

The 6.7 Powerstroke glow plug harness is not a 'when it fails' part, it's a 'check it first' part

I keep seeing guys at the shop in Denver replace entire glow plug sets when a truck has a hard start, and they skip the $80 harness. That harness gets brittle after 50,000 miles in our climate, and a bad connection on cylinder 3 or 5 will mimic a dead plug. I've fixed three rigs this month just by swapping the harness. How many of you actually test the circuit before pulling the valve cover?

Remember when we used to just guess on injection timing?

I was fixing a 7.3 Powerstroke that kept losing power, and my old boss would always say to just 'turn it till it sounds right'... then I finally got a timing light and saw we were off by almost 4 degrees. The difference in how it ran was like night and day, and it made me realize how much we used to leave on the table. Do you guys still run into shops that try to do things the old 'by ear' way?

Changed my mind on cheap torque wrenches after a $80 mistake

I always bought the bargain bin ones for under $50, but one over-torqued a head bolt on a 6.7 Powerstroke last week and cost me a gasket set and a weekend. What's a decent mid-range brand you guys actually trust?

Got into it with a client over a simple glow plug swap

This guy insisted I was overcharging him for glow plugs on his Duramax. I showed him the labor time guide and he still argued. Some people just don't get that diesel work ain't cheap.

Glow plug oversight on a chilly morning taught me a lesson.

Now I test them before every cold season starts.

I swore by my feel for torque until this one rebuild

The spec sheet exists for a reason, learned the hard way.

My diesel's rough idle was cured by a quick MAP sensor cleaning

I was ready to pull the injectors but a five-minute clean of the MAP sensor smoothed everything out, so always check the simple stuff first.

Can we talk about the red tape with warranty repairs on diesel engines?

I spend hours on paperwork just to get a simple part covered under warranty. Some shops love the system because it guarantees payment, but I find it slows everything down. Do you think warranty processes help or hurt how we get work done?

Rant: The move to DEF systems has everyone chasing phantom faults instead of checking simple stuff.