c/diesel-mechanics

Ever try to get a stuck bolt out with a regular wrench versus a proper impact? Had one on a Duramax water pump that wouldn't budge.

Spent 45 minutes reefing on a 3/4-inch wrench with a cheater pipe, nothing. Grabbed the 1-inch drive impact, three ugga-duggas and it spun right out. What's your go-to for seized hardware on older engines?

Had to pick between a cheap rebuild kit or a whole new turbo for a 6.0 Powerstroke

The customer wanted to save cash, so we went with the rebuild kit from a local parts house. It lasted about 4,000 miles before the bearings went out again, and now we're doing the whole job over. Anyone have a go-to brand for a full turbo unit that actually holds up?

Hot take: I used to swear by the old-school feeler gauge for valve adjustments on my 7.3 Powerstroke, but after burning a set last year, I switched to a dial indicator and it's way more consistent.

The feeler gauge method left too much room for error on worn rocker arms, so I made the switch after a buddy in the shop showed me his setup, and now I won't go back, what's your go-to method for setting valves on an older engine?

Warning: The new shop in Boise is using a different kind of fuel additive in their bulk tanks

I was picking up a part over in Boise last week and stopped by that new diesel shop on the main strip. I got talking to the owner while he was filling his bulk tank for the pump outside. He showed me the drum he was using, and it wasn't a standard cetane booster or anti-gel. It was this all-in-one formula that also has a lot of detergent and, get this, a lubricity enhancer that's not just the usual stuff. He swears it's better for the newer emissions systems and keeps injectors cleaner. But it got me thinking, is mixing all those jobs into one additive really smart? Part of me thinks a targeted treatment for the specific problem (like just anti-gel in winter) is the way to go, but he says his bulk customers love the simplicity. Has anyone else run into shops switching to these combo additives, and what's your take on them for fleet maintenance?

I finally gave in and tried that ultrasonic injector cleaner at the shop

Honestly, I thought it was just a fancy gimmick, but after clearing a persistent miss on a 6.7 Powerstroke that wouldn't respond to anything else, I'm a believer. Anyone have a different go-to method for really clogged injectors?

I finally looked up how much a single bad injector can cost a fleet

Was reading a case study from a big trucking company in Phoenix last night. They tracked one rig with a failing injector for three months before it got fixed. The extra fuel burn and lost time added up to over $8,000, not even counting the repair bill. I always knew it was bad, but seeing that number in black and white was a shock. How do you guys catch those early before they bleed a company dry?

Just read that some new heavy duty trucks are running at 15,000 psi fuel pressure

I was flipping through a trade magazine at the parts counter yesterday, waiting on a fuel filter for a Duramax. There was an article about the latest emissions tech, and it said some of the new common rail systems are hitting injection pressures of 15,000 psi. That's insane to me. I've been wrenching for a while and remember when 5,000 psi was a big deal. It makes sense for cleaner burn, but the tolerances on those pumps and injectors must be microscopic. One tiny piece of dirt would just wreck everything. It got me thinking, is this push for higher and higher pressure actually worth the headache for us on the repair side, or is it just creating more fragile, expensive systems that are harder to fix in the field? What's the practical limit before it's just too much?

Update: I finally got the hang of reading injector cutout tests on our new scanner

For years, I just looked for the big drop in RPM on our old Snap-on unit and called it good. Last month, I was chasing a rough idle on a 6.7 Powerstroke and the old way wasn't showing me anything. I sat down with the manual for our new Autel and learned to watch the actual fuel trim numbers for each cylinder during the test. It showed me cylinder 3 was way off, which led me to a bad injector connector I would have missed. What's the one diagnostic trick that took you way too long to learn?

Spent a whole Friday chasing a phantom knock on a 6.7 Powerstroke

The truck came in from a farm near Salina with a solid knock at idle. I checked the obvious stuff, injectors, lifters, you name it. After 7 hours of tearing into it, my apprentice pointed out a loose heat shield on the turbo downpipe that was tapping the block. Felt like a total goof. Anyone else ever waste a day on a noise that simple?

My 8-year-old nephew asked me why diesel engines are so loud. His guess was 'angry robot bees'.

Shoutout to the guy who told me to stop using that fancy fuel additive on my 7.3 Powerstroke

I thought he was full of it. For years I'd been dumping that expensive additive in every tank, convinced it was keeping my injectors clean. Then my buddy, who runs a fleet of old Fords in Wyoming, showed me his fuel filter after 15,000 miles with just straight #2 diesel. It looked cleaner than mine after 5,000. He said, 'Kai, you're just making expensive pee.' I switched to plain fuel six months ago. Zero power loss, starts just as good in the cold, and I'm saving about $80 a month. Sometimes the simple way is the right way. Anyone else run their rigs on straight diesel and have the same results?

Question about using a heat gun on seized turbo bolts

Everyone at my shop says to soak them in penetrating oil for days, but I had a 6.7 Powerstroke last week with a turbo that wouldn't budge. I tried the oil for two days, nothing. Out of ideas, I hit the bolts with a heat gun on high for about 90 seconds each, not red hot, just really warm. They came right out with a regular wrench, no broken studs. The other guys said I'd wreck the gasket or warp something, but it worked fine. Has anyone else had luck with careful, direct heat instead of waiting on oil?

This farmer in Nebraska looked me dead in the eye and asked if I could 'make his tractor sound less angry' after I fixed the injector pump.

I was under the hood of his old John Deere 4020, and he just stood there waiting for an answer, completely serious, like I had a volume knob for diesel clatter.

My uncle swore by using ATF to free a stuck diesel injector

He told me to pull the injector, fill the cup with automatic transmission fluid, and let it sit overnight. I tried it on a 7.3 Powerstroke that came into the shop last week. After about 12 hours, I cranked it over and it fired right up, no more misfire. I was pretty shocked it worked that well, honestly. I always figured you needed a special solvent or just had to replace it. He said the detergents in the ATF break down the carbon better than diesel alone. Has anyone else tried this trick, or is there a better way you've found for a really stuck injector?

Had to pick between a new injector or a full rebuild on a 6.0 Powerstroke last week

The truck came in with a bad miss, and my boss gave me the call. We could either slap in a single new injector for about $500 and hope, or pull the whole cab and do the full bulletproof kit for a few grand. I went with the injector, thinking we got lucky. Two days later, the customer was back with a blown head gasket. Should have just done the job right the first time. Anyone else have a 6.0 story that makes you shake your head?

Got called out for a runaway engine on a farm in Iowa last spring

It was an old John Deere 4020 that the owner said just wouldn't stop. I got there and saw it screaming, oil everywhere. First thing I did was block the air intake with my shop rag to choke it out, which worked but was sketchy. Found the injection pump rack was totally stuck from gunked-up old fuel. Had to pull the pump, clean everything with some Berryman's, and reset the timing. Anyone have a better method for dealing with a stuck rack on those older pumps?

Spent a full day chasing a weird knock in a 6.7 Powerstroke that turned out to be a loose toolbox

Had a 2015 F-250 in the bay with a customer complaint about a rhythmic thumping that got faster with engine speed. We pulled valve covers, checked injectors, even dropped the oil pan looking for a spun bearing, nothing. After about 8 hours, my buddy Mike lifted the back seat to check the jack and found his own socket set rolling around in a cavity under the floor mat. The noise was just a 10mm socket and a wrench bouncing in a plastic tray. Anyone else ever wasted a ton of time on a 'problem' that was just something dumb rattling around?

A crusty old guy at a truck stop in Flagstaff told me my fuel filter change was a waste of time

I was swapping out a primary fuel filter on a 6.7 Powerstroke in the parking lot, doing my usual quick swap and priming the system. This older guy, who looked like he'd been turning wrenches since the 70s, leaned out of his rig's window and just said, 'Kid, you're leaving half the water in the bowl.' I was confused, so I asked what he meant. He pointed out that I wasn't letting the filter housing drain completely before I put the new one in, so any water or junk at the bottom just got mixed back in with the new fuel. Now, I always crack the drain valve and let it drip for a full minute into a cup, even if it looks clear. You'd be surprised how much extra gunk comes out sometimes. What's one small step in your routine that you changed after getting called out on it?

Appreciation post: A trick with a mirror saved me hours on a Detroit Series 60

Last month in the shop, I was chasing a phantom oil leak on a 2003 Freightliner and my boss said, 'Try a dentist's mirror on a stick.' I taped a small mirror to a piece of coat hanger, snaked it behind the block, and spotted a cracked O-ring on the oil cooler line in about five minutes. What's your go-to trick for finding hidden leaks?

Showerthought: I called those magnetic oil drain plugs a scam until my buddy's truck proved me wrong

For years, I told anyone who would listen that magnetic drain plugs were just a way to sell you an extra part. I figured if you changed your oil on time with good filters, you didn't need one. Then my friend with a 6.7 Powerstroke in his F-350 had me help with an oil change last month. He'd been running one for about 30,000 miles. When we pulled his plug, it was covered in a fine, gritty metal fuzz, way more than just normal wear particles. It wasn't chunks, but it was enough to make me pause. That stuff was stuck to the magnet instead of circulating. Now I'm wondering if they're actually worth it for catching early signs of trouble, especially in high-mileage engines. What's the verdict here, are they a legit diagnostic tool or still just peace of mind?

My uncle said to always use a torque wrench on injector hold-downs, but the old head at my shop swears by 'feel'.

I snapped a bolt on a Duramax following the 'feel' method after my uncle warned me. Who's right here, the manual spec or the experienced hand?

Tried a different way to clean a stuck EGR valve on a 6.7 Powerstroke

I used a mix of brake cleaner and a soft brass brush after the usual soak didn't work, and it actually came out way cleaner than I expected. I mean, I thought for sure I was gonna have to pull the whole cooler, but it freed up and passed the vacuum test. Anyone have a go-to method for really stubborn carbon on these, or was I just lucky this time?

Showerthought: I spent $150 on a cheap scan tool and it actually saved my bacon

I was working on a 2015 Duramax that had a weird intermittent power loss. The owner said it felt like it was being held back, but no check engine light. My old scanner couldn't see anything, so I was about to start throwing parts at it. On a whim, I grabbed a $150 Autel scanner from the parts store, figuring it was a gamble. Hooked it up and found a stored code for a turbocharger vane position sensor that wasn't triggering the light. The data stream showed it was sticking. I mean, idk, maybe it's just me but I would have spent way more than that on a turbo or an EGR valve trying to guess. That little tool paid for itself in one afternoon. Has anyone else had a surprisingly good experience with a budget diagnostic tool?

Unpopular opinion: a dab of anti-seize on injector threads is a game changer for old farm equipment

Working on a 30 year old John Deere tractor last month, the guy said he'd had three mechanics walk away from the stuck injectors. I was about to do the same after snapping a socket extension. Out of pure frustration, I heated the area with a torch for about 90 seconds, let it cool, then put a tiny bit of copper anti-seize on the threads of a new injector before gently working it in and out. It acted like a cutting paste and cleaned the threads enough to get the old one out. Saved a full day of drilling. Anyone else have a weird trick for seized parts in aluminum heads?

Unpopular opinion: I ran a 6.7 Powerstroke on straight 5W-30 for 500 miles and it didn't blow up

We had a real mess with a 2019 F-250 in the shop. The owner had put some weird aftermarket oil in it and it turned to sludge. I had to flush the whole system three times. I was out of our normal 15W-40 fleet oil and needed to get it running for a test. All I had on hand was a case of full synthetic 5W-30 meant for gas pickups. I figured, what's the worst that could happen for a short drive? I put it in, ran it hard on the highway for about 500 miles over a week, and checked the oil pressure the whole time. It held perfect pressure, even pulling a load. The oil looked clean when I drained it. I'm not saying to do this, but it made me question how picky these new engines really are about weight. Has anyone else pushed the limits on oil specs and been surprised?