c/diesel-mechanics

Am I the only one who sees people reusing injector copper washers?

Watched a guy in my shop try to save $3 by putting old copper washers back on a 6.7 Powerstroke. That injector started leaking within 20 miles and washed the cylinder down. How many times do you guys see people skip crush washers just to save a few bucks?

Ngl, I tried using WD-40 to clean my injectors and it gummed everything up

Sprayed it on a set of 1999 Cummins injectors thinking it'd loosen the carbon, but instead it turned into a sticky mess that took 3 hours with brake cleaner to flush out. Anyone else make the mistake of using that stuff on fuel parts?

Rant: Old school mechanical injection pumps vs these new electronic ones on the highway last Friday

After helping a buddy swap a failed 2007 ECM-controlled pump on his Freightliner and seeing that old 12-valve P-pump from 1995 fire right up with no computers, I'm starting to wonder if simplicity is worth more than all that emissions garbage, anyone else sticking with mechanical stuff on principle?

Last Tuesday a farmer showed me I've been bleeding brakes wrong for years

I was out at a job near Salina, Kansas helping this old timer with a 12-valve Cummins. He watched me pump and hold for like 10 minutes and just shook his head. Then he showed me his gravity bleed method using a clear hose and a milk jug. It took half the time worked way better. Has anyone else switched from traditional two-person bleeding to something simpler?

Bought a cheap injector puller from Amazon and it cost me a full Saturday

I needed to pull some stuck injectors on a 6.0 Powerstroke last month and figured I'd save $50 on a puller set from some random brand. Big mistake. The puller snapped on the third injector and left the threaded adapter stuck halfway in. Spent 4 hours drilling that thing out and another 2 rigging up a slide hammer setup. The whole job should have been a 3 hour deal. Ended up buying the OTC kit for $180 after that mess and it worked perfect first try. Stupid tax hit me hard on that one. Anyone else got burned by cheap specialty tools on these engines?

Did a valve adjustment on a 6.7 Cummins at 150k miles yesterday, the difference in sound was crazy

I mean I've heard people say it's worth doing but I didn't expect that much change. It was ticking pretty bad before, now it's way smoother at idle. My buddy told me to check the lash on the exhaust side first cause those always tighten up. He was right, three of them were at like .008 instead of .015. Has anyone else seen that pattern on the later model 6.7s?

Hit 200 engine rebuilds this week without a single comeback

Been keeping a log since I started at Thompson Truck Repair in Akron back in 2019. Wednesday morning I pulled the head off this Cummins ISX and realized it was number 200 for me. Never thought I'd get that far without someone yelling at me for a leaky head gasket or bad timing. Anyone else track their jobs just for peace of mind?

Just realized my old mentor was right about injector timing after 15 years

I was talking to my dad's buddy, a guy who's been turning wrenches since the 70s, and he said I was overthinking the timing on a 12-valve I was rebuilding. He told me to just listen to the engine knock and adjust from there, not chase the spec sheet numbers. Has anyone else had a old-timer show them a trick that made you feel like you forgot the basics?

Took me 10 years to stop over-torquing head bolts by feel

I used to think I could torque head bolts by hand. I've been doing diesel work since 2004 and always thought the torque wrench was for rookies. Then I had a 6.0 Powerstroke blow a head gasket 8 months after I did the job. The head bolts had stretched because I went way past spec. Now I use a calibrated torque wrench every single time and I check it against the shop's master gauge twice a year. Does anyone else still know a guy who does it by feel and swears it works?

That time a veteran tech told me to stop using anti-seize on glow plugs

Old timer named Dave at the shop near Texarkana swore I was wrecking threads by putting anti-seize on glow plugs. I argued with him for a solid 10 minutes saying it's standard practice on anything with steel threads going into aluminum. Tell you what though, after I snapped one off in a 6.0 Powerstroke and spent 4 hours extracting it with a reverse drill bit I started thinking maybe he had a point. Anyone else run into issues with anti-seize on glow plugs or was I just unlucky that day?

Took me 15 years to realize I'd been torquing head bolts wrong the whole time

I always did the torque sequence by feel until a Cummins blew on me last year. When I finally looked at the manual it said three passes instead of two. Anybody else learn a basic habit that was dead wrong for years?

Switched to bypass oil filters on my F-250 and oil looks clean at 10k miles

Ngl I was skeptical about those bypass setups for a while, but after 10,000 miles on the same oil, my sample came back with no metal shavings. Cut the filter open and it looked almost new. Anyone else run these long term?

Went to a truck stop in Bakersfield and noticed something about the idling

I pulled into that TA off the 99 last Tuesday to grab coffee and saw a dozen trucks running their engines for over an hour in 68 degree weather. Must have been burning through diesel like crazy for no reason. Anybody else see drivers just not bother shutting down when temps are fine?

Saw a guy at the Freightliner dealer outside Nashville use a heat gun on a frozen injector... changed how I handle stuck fittings forever.

Finally figured out why my 6.0 Powerstroke was puking coolant at the degas bottle

I know the 6.0 gets a bad rep but mine has been decent until last month when it started pushing coolant out after a hard pull. I chased head gaskets for weeks but then a buddy told me to check the oil cooler and the ford EGR cooler bypass on the passenger side. Turned out the oil cooler was partially plugged causing high temps. I swapped it out with an OEM cooler and a new updated standpipe and it's been solid for 3 trips now. Anyone else have that moment where you overlook the simple stuff and go straight to the nightmare scenario?

Found a cracked cylinder head on a freightliner at 3am last Friday

I was doing a routine oil change on a 2018 Cascadia at a truck stop in Oklahoma City when I spotted a hairline crack near the #6 injector cup. Pulled the head off around 2am and spent the next few hours cleaning up the surface. Turned out the previous guy overtightened the hold down bolts by a good 20 ft-lbs. I managed to get a reman head delivered by 7am from a shop 30 miles out. Got the truck back together by noon and the driver made his delivery. Anybody else run into cracks from overtorquing those injector hold downs?

Overheard a guy at the parts counter say injectors don't fail, they just get neglected

I was picking up a fan belt for a 5.9 Cummins last Friday at the shop in Akron and this older mechanic is telling the kid behind the counter that he never sees injectors actually wear out from age or mileage. He said it's always dirty fuel or water in the system that kills them. That really stuck with me because I've replaced three sets in the last two years on fleet trucks and now I'm wondering if I should be checking the fuel filters more often. Our shop does them every 15k but maybe that's not enough. Anyone else ever hear something like that or am I just overthinking this?

I finally got a Cat C15 to fire up by ditching the ECM flash entirely

Had a 2006 Pete with a C15 that just would not start no matter how many times I reflashed the ECM. Everyone in the shop kept telling me it had to be a ground issue or a bad crank sensor. On a hunch I bypassed the ECM and jumped the fuel shutoff solenoid directly off a 12V test lead at the battery box, and she fired right up. Turned out the ECM had a internal power supply failure that was killing all the fuel commands. Has anyone else seen ECMs that pass diagnostics but still drop the fuel signal like that?

Just realized I hit 500,000 miles on my old Cummins today

I was just doing a routine oil change on my 2002 Dodge Ram 2500 and glanced at the odometer. It rolled right past 500,000 miles while I was draining the pan. That truck has been through two transmissions and three turbos, but the block itself has never been cracked open. I bought it for $3,500 back in 2015 from a guy in Bakersfield who used it for hauling hay. Half a million miles feels like a weird milestone, but it got me wondering how many of you have hit that mark. What's the highest mileage diesel you've personally kept running?

A guy at the shop told me I was wasting time torquing oil pan bolts by feel, so I finally bought a inch-pound torque wrench last week and haven't snapped a bolt since.

He showed me his own setup with a $60 CDI torque wrench and after I snapped my third pan bolt on a Ram 3500 I figured it was worth the money, anyone else have a cheap tool they ignored for way too long?

Got told my torque wrench method was wrong after 15 years... they were right.

Used a little too much thread sealant on a fuel line fitting and it caused a weird drip

I was fixing a leak on a Duramax fuel line at the shop yesterday and really loaded up the threads with Permatex 59214. Thought more was better, you know? It sealed fine at first, but after the engine got hot, a tiny bit of the sealant softened and started dripping down the line, looking just like a fuel leak. Took me an hour to trace it back. Learned that a thin, even coat is way better than packing it in there. Anyone else run into sealant acting weird when it gets too hot?

Pro tip: A snapped injector hold-down bolt taught me to always use a backup wrench

I was doing an injector swap on a 6.7 Powerstroke in a shop in Boise last Tuesday. I was torquing the last hold-down bolt to 44 ft-lbs when it snapped clean off, leaving the threaded portion stuck in the head. I had to pull the valve cover, drill it out, and chase the threads, which added about three hours to the job. The lesson was that the torque spec is fine, but you need a second wrench on the socket to keep it perfectly square to the bolt head. Has anyone else had a bolt snap at spec, or is there a better method to prevent this?

TIL the old truck stop in Flagstaff has a free tool library for drivers

I was passing through last month and saw a sign by the diesel pumps about a 'community wrench box'. Turns out they keep a locked cabinet with basic sockets, wrenches, and a torque wrench that truckers can sign out if something comes loose on the road. The guy at the counter said a retired mechanic set it up years ago to help folks in a pinch. Has anyone else seen a shop or stop offer something like this? I think it's a pretty cool idea.

Rant: The 'quick fix' from last month just blew a turbo

Honestly, a fleet manager insisted we just clean the MAP sensor on a Duramax instead of doing the full diagnostic he paid for. Three weeks later, the truck's on the hook with a shredded turbo because the real issue was a failing EGR cooler. Anyone else constantly fighting this 'just make it run' mentality?