c/diesel-mechanics

Question about those magnetic oil drain plugs

I always thought they were a gimmick until I pulled one from a 6.7 Powerstroke that had been running for 80,000 miles and it was covered in fine metal fuzz. Now I'm putting them on every service truck I touch. What's the weirdest thing you've ever caught on one of these?

Shoutout to the $80 magnetic parts tray I got for my service truck

I was doing a water pump swap on a Duramax in a gravel lot last month, and a tiny but vital bolt fell. It would have been gone forever, but it stuck right to the tray. That thing has saved me so much time crawling around. Anyone have a good brand for the bigger magnetic mats you can roll out under an engine bay?

My uncle told me to always use a torque wrench on injector caps, and he was right after I cracked one on a 6.7 Powerstroke.

I thought I could feel it, but the spec was 18 ft-lbs and I went over by maybe 5, which cost me a $90 part and a whole afternoon.

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

Had a P0087 fuel rail pressure code on a 2015 F-250 that would NOT clear. Spent 8 hours, my whole Saturday, replacing the high pressure fuel pump. Turns out it was just a slightly sticky pressure relief valve on the rail itself, a $40 part. I feel like an idiot for not starting with the cheaper check. Anyone have a better diagnostic order they follow for these?

Showerthought: a frozen injector line in Fargo changed how I check for air leaks

I was working on a 6.7 Powerstroke last winter, and it kept losing prime after sitting overnight. Spent a whole morning looking for a fuel leak, but everything was dry. Finally, I grabbed a spray bottle of soapy water and misted the injector lines while the engine was running. Found a tiny bubble forming on a line right where it goes into the head, a spot I never really checked before. The line had a hairline crack that only opened up when it got warm. Now I always start with the soap test on cold lines, even if they look fine. Anyone else find weird leaks in places you wouldn't expect?

Pro tip: I used to swear by a 3/4 inch impact for lug nuts, but a 1 inch drive with a torque stick is the only way to go.

The extra torque and control on a Freightliner's wheel ends means you won't fight a stuck nut for 20 minutes like I did last week. Anyone else made the switch and noticed fewer busted studs?

Watch out for that 'simple' coolant leak on the 6.7 Powerstroke

Spent a whole day on what looked like a loose hose clamp on a 2015 F-250. The leak was actually coming from the oil cooler housing gasket, which is buried under the turbo and a bunch of other stuff. It took me and another guy almost 9 hours to tear down, replace the gasket, and get it all back together. Has anyone found a faster way to get to that housing without pulling half the engine bay apart?

TIL a cheap torque wrench can cost you a whole Saturday

Honestly, I was trying to save a few bucks last month and grabbed a no-name torque wrench from a discount tool truck for like $40. Figured it would be fine for some head studs on a 6.7 Powerstroke. Ngl, I spent the entire day torquing everything down in sequence, felt good, started it up, and immediately heard a nasty tick. Had to pull the valve cover right back off and found two studs were way under spec. The wrench was reading 90 ft-lbs but was actually putting out maybe 60. Wasted a full 8-hour day and a fresh head gasket. Has anyone else been burned by a bad torque wrench, and what brand do you actually trust for engine work?

I finally gave up on that aftermarket fuel filter housing for my Duramax

Had a customer's truck die on the highway last Tuesday, towed it in with a no-start. Traced it to the cheap aluminum housing I put on six months ago, it cracked right at the thermostat port and dumped all the fuel. I swapped it back to a stock unit yesterday and it fired right up. Anyone else had a similar failure with those shiny aftermarket parts?

Spent three hours chasing a phantom electrical gremlin on a 6.7 Powerstroke

It turned out to be a single corroded pin in the main harness connector I'd already checked twice. I finally found it by wiggling each wire while the engine was running. Anyone have a better method for tracking down intermittent connection issues like that?

Switched from a regular impact to a stubby for tight engine bay work and it's a game changer

I was doing a turbo swap on a 6.7 Powerstroke last month and kept dropping my standard impact trying to get at the lower manifold bolts. My buddy loaned me his Milwaukee M12 stubby and I got every bolt out in under 10 minutes. Now I use it for anything in a cramped space, saves so much time and knuckle skin. What other small tools have you guys found that make a huge difference on big jobs?

Vent: The 6.7 Powerstroke oil filter housing that fought back

Had a job last week on a 2015 F-250 where the plastic oil filter housing decided to fuse itself to the block. Tried the special socket, tried heat, ended up using a 3/4 inch drive breaker bar and a cheater pipe, and the whole thing just sheared off flush. My apprentice just stared and said, 'Well, that's new.' Anyone have a better method for when they're really stuck, or is it just a prayer and a new housing every time?

Warning: I just logged my 500th hour on a single engine rebuild for a 6.7 Powerstroke and the number actually scared me a little.

The owner kept adding 'while you're in there' items, turning a simple top-end job into a full teardown, so what's the most hours you've ever sunk into one vehicle before it felt like a black hole?

A guy at the shop told me my fuel line routing was asking for trouble

He said 'that's a vibration crack waiting to happen' and showed me to leave a 2-inch service loop near the pump. How do you guys handle line stress on older Cummins engines?

Warning: Got roasted for my old torque wrench method on a Detroit 60 series

A veteran tech in Tulsa told me 'you're leaving 50 ft-lbs on the table with that click-and-go crap' after a head gasket failed. Now I always do a final pull with a calibrated beam wrench, anyone else switch up their routine after getting called out?

Update: I finally stopped using the 'feel' method for injector timing and it fixed a whole shop's worth of problems

For years, I was taught to time injectors by feel, lining up the marks and then giving the pump a little nudge 'until it felt right.' I did it on everything from old 7.3s to newer Duramaxes. The tip off was a 6.7 Powerstroke that came in from a fleet in Boise. It had a rough idle and low power, and I'd timed it myself three weeks prior. My boss had me put a timing light on it, and we were off by almost 4 degrees. That small number explained the whole job. I realized I'd been trusting my hands over a $200 tool this whole time. Now I clock everything, no exceptions. Has anyone else had a basic shop practice fall apart under simple testing?

Can we talk about how everyone treats the 5 micron fuel filter like it's the only one that matters?

I keep seeing guys in the shop and online act like the primary filter on a Duramax or Powerstroke is just a big pre-filter, but that's not right. The 30 micron primary filter catches the big stuff that would wreck your injection pump, and the 5 micron secondary gets the fine silt. I watched a tech in our shop skip a primary change on a 6.7 Cummins because 'the secondary was clean', and three months later we had to replace a $2,800 CP4 pump. The service interval is there for both filters for a reason. Has anyone else seen a pump failure that could have been avoided by just following the full filter schedule?

Switched from a basic scan tool to a proper JPRO setup for our fleet trucks

I've been using a cheap generic scanner for our six Freightliners, but it kept missing weird transmission codes. Last month I finally got the shop to spring for a JPRO kit. The difference is night and day, it actually reads the TCM properly and shows live data from all the modules. I fixed a persistent shifting issue on truck number three in about an hour that had been bugging me for weeks. Anyone else have a favorite diagnostic platform for heavy duty stuff?

I just hit 500 hours on my rebuilt 6.0 Powerstroke without a single injector code

I've been working on these engines for years and always told guys to budget for injectors around the 300 hour mark after a rebuild, especially if you don't do a full oil cooler and EGR delete. I had this one customer with a 2005 F-250 who insisted on just the basic bulletproofing, no fancy aftermarket parts. I figured we'd see him back in six months. He rolled in yesterday for a tire rotation and I scanned it out of habit. Zero codes, FICM sync perfect, and the hour meter read 502. I used Archoil additive in his last two oil changes, but I still thought it was a fluke. Now I'm wondering if the quality of the OEM rebuild kit I used this time, from a supplier in Boise, made a bigger difference than I gave it credit for. Has anyone else seen a stock-ish 6.0 go this long on fresh injectors without issues?

My uncle told me to always use a torque wrench on injector hold-down bolts, even the small ones.

He said a guy in his old shop in Tacoma snapped one off in a 6.7 Powerstroke head by just going by feel. I finally bought a good 1/4 inch drive torque wrench and started doing it right. Has anyone else had a bolt let go on them from over-tightening?

Vent: I put a 3rd gen Cummins turbo on a 12 valve just to see what would happen

Honestly, it spooled up way faster than I expected and actually gave me better low end than the old setup. Anyone else messed with a weird swap like that?

Guys, stop using the wrong torque spec on 6.7 Powerstroke head bolts. I've seen three trucks come back with leaks in the last two months.

Spent a whole weekend chasing a coolant leak that wasn't there...

Had this old 7.3 Powerstroke come in with the owner saying it was puking coolant after a short drive. Pressure tested it, held fine cold. Ran it up to temp, no leak. Drove it around the block, nothing. Spent hours checking every hose, the water pump, even pulled the thermostat housing. Finally, after two full days of this, I noticed the coolant reservoir cap was from a completely different truck... some off-brand thing with a weaker spring. It would only vent under a specific load going up a hill near his house. The actual 'leak' was just vapor blowing out the overflow tube for a second. Eight hours of work for a $12 cap. Anyone else ever get fooled by a bad cap like that?

Shoutout to the old timer who showed me the soap trick for finding air leaks

Honestly, I thought the guy was just messing with me when he said to use a spray bottle of soapy water. That was three years ago at the shop in Tacoma. I was chasing a rough idle on a 6.7 Powerstroke for two days, checking sensors and lines. I finally tried his dumb trick, sprayed the intake boots, and saw bubbles instantly at a tiny crack. Has anyone else got a simple fix that actually works like that?

Spent three days chasing a phantom knock in a 6.7 Powerstroke

Had a 2015 F-250 come in with a light knock only under load. Thought it was a simple injector issue, so I swapped the suspected one. Noise stayed. Checked the turbo, the up-pipe, even pulled the valve covers looking for a loose rocker. Finally found a tiny crack in the exhaust manifold, right where it bolts to the head, that was only opening up when the engine got hot and torqued over. That little hairline crack cost me about 18 hours of diag time. Anyone else been fooled by a noise that turned out to be something simple in a weird spot?