c/diesel-mechanics

I finally listened to my brother-in-law about those new DEF system cleaners

He's a fleet manager for a trucking company in Toledo and told me he's seen a 15% drop in regen cycles since his shop switched brands. Has anyone else had a specific product actually make that big of a difference?

A quick tip on checking for injector knock that saved me a ton of time

Honestly, I see a lot of guys just listening for a knock and assuming it's a rod bearing. Ngl, on these 6.7 Powerstrokes, a lot of that noise can be a single bad injector. I hook up a scan tool and watch the cylinder contribution numbers while it's running rough. The one that's way off, like showing +4.0 or more, is usually the culprit. I found this out after swapping two good injectors on a truck last month before I checked the data. Has anyone else had a knock turn out to be just an injector on a different engine?

Showerthought: I used to think a good cleaning was enough for an oil change

For years, I'd just wipe the filter housing and slap the new filter on. It was quick and seemed fine. Then, about six months ago, I had a 6.7 Powerstroke come back with a low oil pressure warning a week after a service. The problem was a tiny piece of old filter gasket stuck in the housing groove, something a rag never gets. Now, I always run my finger around the whole groove to feel for any leftover bits, and I use a small pick to clear the channel. It adds maybe thirty seconds to the job, but it stops a comeback. That one mess up cost me an hour of free labor to fix. Has anyone else found a simple step they started doing that saved a lot of trouble later?

Shoutout to the old timer who showed me the zip tie trick for a stubborn fuel line

Working on a 2012 Duramax with a fuel line that just would not seat right on the filter housing. I was about to order a special clamp tool. This guy in the next bay walks over, grabs a small zip tie, and cinches it around the line's collar before pushing it on. The extra grip let it click into place first try. Has anyone else found a simple fix like that for a job that seemed to need a special tool?

A guy at a truck stop in Flagstaff showed me a trick with a zip tie and a glow plug

I was stuck on the side of I-40 last fall with a truck that wouldn't start, and it was getting cold. An older driver pulled over to help. He listened to it crank for about five seconds, then said, 'Bet it's a glow plug controller, but let's see.' He didn't have a test light, so he took a zip tie, stripped the end with his pocket knife, and poked it into the glow plug bus bar connector while I turned the key. He held the other end near the block. When it sparked, he just nodded and said, 'You got power to the bar, but the plugs are cold. Means the controller's telling lies.' It was such a simple, fast way to check without pulling anything apart. I carry a few zip ties in my box now just for that. Has anyone else run into a controller that sends voltage but no pulse width?

Got called out for my fuel line crimp method last month

I was working on a Duramax injector line in our shop, using my old hand crimper like always. This old timer from the next bay, Frank, walks over and just watches for a minute. He finally says, 'Kid, you're squeezing it like a lemon. You need three crimps, not two, and you gotta feel the click on the second squeeze, not just crank it.' I was annoyed at first, but he showed me on a scrap line. The difference in the crimp was clear. I tried it his way on the next job, a Powerstroke with a weeping line. No leak, first try. Now I do the three-step crimp every single time. It feels slower, but I haven't had a comeback on a fuel line since. What's one piece of shop advice that sounded picky but actually worked for you?

Visited a salvage yard in Spokane and saw a trick for pulling injectors

I was looking for a turbo core last week at a big yard off I-90. One of the older guys there had a 6.0 Powerstroke block on a stand and was using a slide hammer with a homemade adapter made from an old socket and a bolt. He welded a nut to the side of the socket to give the hammer a solid hook point. Said he's pulled over a hundred injectors with that same tool and never cracked a rocker box. Has anyone else seen a homemade tool setup that worked better than the store-bought version?

Just read an old Detroit Diesel manual and the torque spec for a 6V92 head bolt was way lower than I expected

It was only 200 foot pounds. I found it in a manual from the 80s at the shop library. I always thought those big two stroke heads needed way more clamp. Has anyone else run into old specs that seem off by modern standards?

I finally bought a $1200 aftermarket turbo for my 6.7 Powerstroke, and now I'm wondering if the extra power is worth the potential reliability hit.

Some guys swear by the extra torque for towing, but others say you're just asking for a blown head gasket down the line, so what's your take on modified vs. stock turbos for daily drivers?

My old way of finding a coolant leak was a total mess

I used to spray soapy water all over the engine bay and hope for bubbles, which just made a slippery mess. After a job in Phoenix last summer where I spent two hours cleaning up, I bought a UV dye kit for about $40. Now I add the dye, run the engine, and find the leak in minutes with a black light. Has anyone else made the switch from old messy tricks to something that actually works?

That time I spent an hour fighting a stuck injector with a slide hammer

I was about to go get a bigger hammer when my buddy walked in and asked why I hadn't loosened the hold-down clamp bolt yet. Turns out I'd been trying to pull the whole assembly out, clamp and all, for 60 minutes straight. Ever had a moment where the solution was embarrassingly simple?

A retired trucker in Billings told me his old Detroit Diesel 8V92 would run on just about anything flammable.

He said they'd sometimes thin the fuel with a little kerosene in the winter, something you'd never try with today's common-rail systems. Makes you appreciate the old iron, but also the precision we work with now, doesn't it?

Just swapped from a standard 3/8 drive to a 1/2 inch impact for lug nuts on a Freightliner.

I was fighting with a set of lug nuts on a Cascadia for twenty minutes with my old 3/8 gun. Borrowed a coworker's Milwaukee 1/2 inch high torque and they came off in three seconds flat. The extra torque and the bigger anvil made all the difference on that heavy hardware. What's your go-to tool for stubborn wheel work?

Just lost a full day's pay chasing a ghost code on a 6.7 Powerstroke

Had a P0087 low fuel rail pressure code on a 2015 F-250. Customer said it was intermittent, so I jumped straight to the high pressure pump. Spent 8 hours swapping it out, only to find the real problem was a tiny crack in the plastic fuel line connector on the CP4 pump inlet, spraying a fine mist you could barely see. Cost me about $300 in lost time because I didn't pressure test the low side first. Anyone else get burned by assuming the worst with these codes?

Wasted $150 on a cheap knockoff torque wrench that snapped on a Duramax head bolt

I bought a cheap code reader for my shop and it cost me a full day's pay

Back when I started, a good scan tool was a big investment, so I grabbed a $80 generic one online. It gave me a weird code on a Duramax, said it was an injector circuit. Spent six hours chasing that, pulling the valve cover, checking wiring. Turns out it was just a bad glow plug module, and my cheap tool read the data wrong. That was a $400 job I lost because I trusted junk gear. Anyone have a solid, budget friendly scanner they actually use every day?

Shoutout to the guy who showed me the trick with the zip tie on a 6.7 Powerstroke injector harness

I was stuck on a farm outside Cheyenne with a no-start, and after two hours of chasing voltage drops, a passing driver saw my hood up, showed me how to loop a zip tie to pull the connector lock, and got me rolling in five minutes flat, so what's the best roadside fix you've ever been shown?

Shoutout to the old timer who called my injector diagnosis

I had a 6.7 Powerstroke with a rough idle and a code for cylinder 3 misfire. I was sure it was a bad injector, so I ordered a new one. This retired mechanic named Ray at the parts counter told me to check the UVCH connector first, said he'd seen it a dozen times. I blew him off, swapped the injector, and the problem came right back. Sure enough, after wasting $300, I pulled the valve cover and found a pinched wire in that exact connector. Has anyone else had a Ford talk them into throwing parts at a simple wiring issue?

Tried cleaning a DPF with a new chemical soak and it came out worse than before

Had a 2015 Ram 3500 come into the shop last month with a clogged DPF. The owner didn't want to pay for a new one, so I figured I'd try this new 'deep clean' chemical soak I saw online. Followed the instructions to the letter, let it sit for the full 24 hours, and rinsed it out with the pressure washer. When I put it back on the truck and ran a forced regen, the back pressure readings were actually higher than before I started. It was like the cleaner just moved the soot around and baked it into a harder cake. Ended up having to tell the customer they needed a new unit anyway, which was a tough call. Learned that sometimes the 'miracle' fixes just waste time and make the job harder. Has anyone else had a chemical clean totally backfire like that? What's your go-to method now when a soak doesn't cut it?

Am I the only one who spent a year tightening valve covers with a 3/8 impact?

I was doing a routine service on a 6.7 Powerstroke in our Houston shop last week and my apprentice just stared at me and said, 'Dude, you know you're supposed to hand-torque those, right?'. I've been zipping them on for ages, thinking the gasket would just squish right. What's the dumbest 'aha' moment you've had with a tool?

Just realized I was using the wrong torque spec on injector lines for months

Had a 2015 Duramax in the shop with a persistent leak. Was using 44 ft-lbs from an old manual. My buddy at the Kenworth dealer said the updated spec is 35 ft-lbs. Switched, leak stopped. Anyone else get burned by outdated service info?

Had a coolant hose blow on a 6.7 Powerstroke in the middle of a job last Tuesday

It was a simple fuel filter swap for a regular customer, just a quick in-and-out. I had the truck up on the lift, filter changed, and was about to button up the skid plate when I heard a hiss and saw steam. A lower radiator hose, the one that runs to the oil cooler, had a split about two inches long right at the clamp. It must have been weak and the pressure from the system just let go. I had to drain the whole cooling system, which took over an hour because of how the air bleeds on that engine. The hose itself was only forty bucks, but it turned a thirty minute job into a three hour ordeal. Customer was cool about it, but it threw my whole afternoon schedule off. Makes you wonder how many other trucks are running around with hoses that are just waiting to pop. Anyone else had a simple job get wrecked by a random part failure like that?

A fleet manager in Toledo told me my valve adjustments were too aggressive

He pulled me aside after a service and said, 'You're setting the intake valves at 0.012 inches, but our engines run hotter on these routes. Try 0.014.' I was skeptical, but I adjusted my process on their next three trucks. Six months later, their callbacks for valve train noise dropped to zero. I've been using his spec on similar highway fleet work ever since. Has anyone else had a customer give them a better spec for a specific operation?

PSA: I wasted $400 on a 'universal' turbo rebuild kit for a 6.7 Powerstroke that was missing half the gaskets.

The seller swore it was complete, but after tearing the whole thing down in my bay, I found out the hard way and had to order the correct parts overnight, so has anyone found a kit supplier that doesn't cut corners?

I finally had to pick between a shop job and hitting the road as a field tech

About 8 years back, I got offered two gigs at the same time. One was a steady spot at a big fleet shop here in Boise, full benefits and a set schedule. The other was a field service job with a trucking company, driving a service rig to fix breakdowns on the interstate. I picked the road. The money was better, sure, but man, those first few winters were rough. I remember one call near Mountain Home at 2 AM, trying to swap a turbo in a blizzard with just my truck's work lights. You learn real fast how to improvise with bungee cords and a tarp. I don't miss the cold, but I got to see and fix problems you'd never see in a clean bay. What's the hardest roadside fix you've ever had to pull off?