Mo miles, mo problems?

[RU55ELL]

This one is for the diesel guys; what do you own, how many miles does it have on it and how many engine related problems have you had thus far? I'm still not really set on anything in particular and have found some diesels with higher mileage (200-300k) and am wonder what I have to look forward to. All input is welcome.

 

[bob91yj]

I've been a service writer at a GMC dealership for 7 years. I've got one of the best Dmax techs on the west coast in my shop, so I've seen my fair share of Dmax's. I'd be more than happy to answer any GM/Chevy questions you or anyone else may have regarding them.
Honestly, at 200-300k miles the rest of the truck is usually worn out unless it is unusually well maintained.
Things to look for on used Chevy/GMC's...
Loose front hub bearings. They typically survive 80,000 to 120,000 miles, less if oversize tires. (I carry a spare)
Loose steering...Pitman Arm, Idler Arm, center link and tie rods are an upgrade opportunity looking for a place to happen. Cognito steering correction kit on stock parts if nothing else (my current set up, I carry spare tie rod and outer end, Kryptonite linkage upgrade on the list)
Transfer case leaking...not super common, but I've seen several that have a hole worn through the case by the oil pump pick up (inside the case), leaking output seal may also need the tail shaft bushing, check for looseness.
Allison transmission is almost bullet proof with even a little maintenance. If the fluid is still red, it's probably OK.
Front end... differential leaking at the case split line...rare, but it happens. Torn CV boots, reman shafts are less than $100, I carry a spare for no real reason. The whole shaft (aftermarket) is cheaper than just the factory boots (and I work there).
Rear end is almost bullet proof as well, maybe two failures in 7 years.
As far as the engine, if it has been maintained, no reason why it won't continue to be a good engine. Dmax's are prone to injector issues. If it smokes at idle, there's a fair chance you have a bad injector. Replacing them is not cheap, and not particularly easy. Parts/labor, you're looking $4500.
Transmission cooler lines and power steering hoses are probably leaking at the crimps from metal tube/rubber hose.

 

[RU55ELL]

I've found some 4-door Super Dutys for those prices with 300k miles and some pre-Super Duty models with ~175-200k miles that I have been interested in. I've been looking to spend less than $6k on the truck, mainly because it will get beat up from wheeling and most are long beds that I will end up bobbing to help from destroying it in the woods. I always hear so much good about the Allison tranny but I don't want to mess with IFS on a heavy truck like that. I would actually rather have the Cummins, especially a 1st-gen Ram, but they are impossible to find in a crew cab and the extended cabs are just way too small for when the whole family comes along.

My problem is, I have absolutely no idea what stuff costs to fix on a diesel.

 

[Bella PSD]

2002 Ford Superduty 7.3L.

130,000 miles and for the most part trouble free. Two sets of o-rings for the oil pump lines, a starter and I think the high-pressure oil relay is starting to act up. That's it other than oil changes and regular maintains. Heck, even the brakes are the originals.

Louie

 

[Buliwyf]

The Ford 7.3s eat cam sensors. Then you have the injectors and water pump. Pretty stout engines, those are pretty nice, simple, problems to have. But they are hard on that 4r100 trans. Rebuilding that is over $2k. The front Dana 50 while kinda weak, never really breaks in any normal condition a Superduty is fit to see.

Gas 1999-2001 Superduties with 150k+ miles are dirt cheap right now. And many look very clean still. Usually about $8k -10k in my area for clean, dent free ones.

The Ford 6.0 likes to spring a leak at the EGR and either flood the engine with coolant, or dump the coolant on the ground while your truck nukes in less than 5 minutes and the heads warp. I was lucky. Ford replaced my EGR but didn't notice my heads, and I got to add a gallon of coolant to the truck every week. I'd avoid the 6.0s.

 

[Metcalf]

I have WAY over 300K on my 1992 Dodge Cummins. The only part that I have replaced that would have put me out of the game was the water pump. The bearing was bead and leaking. The replacement pump as been good for 3+ years now.

Other than the water pump the only thing I have to the engine done is change fluids/filters.

I did have to rebuild the clutch linkage at the pedal. It was just flat worn out. If the previous owner would have caught it sooner it would have been a straight off the shelf parts repair.

The steering was a junk system from the factory and was probably on of the best upgrades so far.

As far as I know the truck started life as a county truck, then was sold to a private guy, then the son took it over a few years before I bought it. I don't even want to know how many loads of firewood he hauled with it.

I do highly recommend the 1st gen Cummins W250 trucks because the entire drivetrain is very rebuildable. Real bearings, no chain drive anything, locking hubs, etc. The body is a dodge product however, I would only buy one in a rust free state.

 

[Buliwyf]

Keep in mind there is no law against pulling your engine and sending it out to be rebuilt when the time comes. There is a company near me that rebuilds tons of engines for my customers. All I have to do is pull it, then put it back in later. The truck or generator is down for a month usually.

 

[Rot Box]

1991 F350 CC 7.3 IDI (not a Powerstroke!) diesel engine just turned over 250K on the odo.

Majors:

160K rebuilt ZF5 transmission and BW1356 T-case
180K rebuilt engine and heads (Untreated coolant lead to cavitation problem resulting in premature engine damage)
214K New radiator
Other than that I have 100+k miles worth of VERY detailed service history (mostly preventative maintenance) if you want me to post all of it :Wow1: :bike_rider:

Everything wears out sooner or later-period. Imo any used truck regardless of age is on borrowed time and unless it is immaculate inside and out mileage means nothing to me on a diesel truck. I had two really nice Dodges (92 and 01) both Cummins powered when I bought my latest truck. I needed 4 full size doors and at the time the Dodges that came with 4 were not in my budget. I ended up going the old Ford route and I've been extremely happy. The IDI's are extremely reliable and dependable. They come with a very stout drivetrain and are much cheaper to repair and maintain than the later model diesels from all makes. Like any early to mid 90's mechanically injected diesel they are new enough to be nice, comfortable and dependable yet old enough that anyone can work on them with basic tooling :coffeedrink:

 

[lllateralus]

The 7.3 Power Stroke is a great motor. They do NOT have 'injector problems'. The injectors are fired using engine oil under high pressure, so on time engine oil changes are mandatory for long injector life.
Change the oil every 5K miles, and since the oil is hardly circulated through the high pressure oil pump, change it in THAT every 5K miles as well. It has its own drain and fill. (even though oil IS circulated through it) It will come out black. Hardly anyone does this.
Mine has (only) 102K miles, original injectors and is smooth as butter.

Learn about it, take care of it, it will last forever.

 

[SixSpeed]

I have a 94 Dodge 3500 Cummins, has 275K on the clock now, I bought it 9 months ago with 250K on the clock. It was a rundown POS if I am honest, was worked hard and put up wet. I Repainted it, new lights, bumpers, tire & wheels, interior, suspension, etc. Truck looks great, never touched the motor though. The truck earns its keep, its always hooked up to 10-25K trailers, and I have to say the engine has never skipped a beat. The transmission is another story...

Its not so much the engine that becomes a problem, its everything else around it. My truck should be good for at least another 100K before it needs a rebuild, maybe even more. There are plenty of 500K+ mile Cummins motors around that have never been rebuilt. If you take care of it, they will last. Just depends how good of shape the rest of the truck is. I wouldn't hesitate to buy another one with 200K+ miles, as long as the rest of it was well maintained, or the truck was cheap enough to warrant doing the work.

 

[bfdiesel]

Had a 04 dmax lb7. Replaced front wheel hubs @ about 100,000. Upgraded all steering components @ 120,00 and had it aligned. @ about 140,000 had the injectors replaced under warranty. @ 173,000 had all injectors replaced under warranty. @ 210,000 traded it for my 07 5.9 cummins ( injectors were starting to go again along with the water pump starting to weep ). If it had not been for the injectors being junk I would still have it. The 5 speed allison was bulletproof mileage was good on the first set of injectors and less on the following sets but still good. I also had to replace all three rear drive line u joints unknown mileage and then the tranny output u joint again 50,000 later.

My dad has an 01 5.9 cummins that has been driven like it is hated since day one and the only thing he has had to do to it is replace the ABS controller due to leaving it parked to long (almost a year). It has about 180,000 and a small oil leak where the ps pump mounts up.

My burb has either 84,000 or 184,000. probably the latter and the motor has a rear main leak, oil pan leak and I fixed the valve cover leak. The water pump had already been replaced along with the starter when I bought it. The tranny was out front pump and 3/4 band/clutch.

 

[Greggk]

I have 268,000 on my 7.3 powerstroke f250 superduty. she runs and drives great. no real issues, except for a broken leaf spring, which i replaced. now i have just little quirks. such as turnsignal switch doesnt always stay engaged and other little nuances, but they will be dealt with soon.

 

[FellowTraveler]

11Year old Burb

My burb has served me well since I took to doing the PM and repairs myself. Studied the GM tech course for my 6.5td.

Only thing I can say about GMC service is they have made it an art blowing smoke where the sun don't shine.

Issues with the factory placement of of fuel injection driver was overcome by installing remote drivers on cooling plates out of engine bay and in airflow front of radiator.

Injectors and main pump have done well and show no signs of giving up on low sulfur fuel because I always add 2 cycle 1oz to 1 gal.

Removed the pesky timing chain for gear drive.

Steering, issues aside normal wear and tear was limited to worn rag joint between steering box and steering shaft and that PITA variable orifice valve (VOV) at back of steering pump which is now gone. A high pressure PSC pump drives the p/s fluid.

Replaced the engine oil cooler lines which break always resulting in blown engine, now use steel AN fittings and quality braided hose now with addition of AMSOIL bypass filtration system.

Lots of extra PM makes things go better and way, way longer than normal.

Oh, how I love the smell of diesel in the morning!

 

[Junior's 12 Valve]

I have 230k on my 24 Valve Cummins, and it's just broken in.

To make things easier I'll list some pros and cons of every brand

PROS:
-Ford
Fastest from the factory, good 4wd system, a lot of power, best interior no doubt, easy and cheap to make power with the 6.4, solid axles.

-Dodge
Most reliable motors, will tow anything you put behind it, easy to work on, relatively cheap to work on compared to other makes, best fuel mileage, easy to make power, (with new clutch) standard trans is bulletproof, when built auto trannys are bombproof, high ground clearence from factory, best 4wd system (imho), solid axles.

-GM
Quick, Allison tranny is very stout when truck is stock, or near stock,

CONS:
-Ford
On 03+ you have to pull cab to change headgasket, V8 not the best fuel mileage, good luck finding a stamdard trans, expensive parts

-Dodge
Stock auto can't handle much power, 24 valve lift pumps need to be upgraded asap to an airdog or fass pump ($400), Dash always cracks, no crew cab until 03.

-GM
IFS, Allison tranny won't handle a lot of power (defueling trans), V8 mpg, weak when towing (personal experience), cheap interior, expensive, hard to work on.

If you don't agree with my post don't flame me, I'm not trying to start a brand war pissin match.

 

[bfdiesel]

"PROS:
-Ford
Fastest from the factory, good 4wd system, a lot of power, best interior no doubt, easy and cheap to make power with the 6.4, solid axles."

Until you try to tow with it then it slows down. The 6.4 is no 7.3 and the 7.3 is no 5.9 Cummins 12v.

"-Dodge
Most reliable motors, will tow anything you put behind it, easy to work on, relatively cheap to work on compared to other makes, best fuel mileage, easy to make power, (with new clutch) standard trans is bulletproof, when built auto trannys are bombproof, high ground clearence from factory, best 4wd system (imho), solid axles."

Duramax and Cummins since 04 are about the same for reliability. Cummins is hands down the easiest to work on as far as being cheapest of course it is an I6 the others are V8's. Everything since 01 is easy to add power to. The newer Duramax's are hands down the best MPG engines (Comparing year for year) the Cummins 6.7 is not even in the ball park. The best economy 5.9 Cummins could compete with the best economy Duramax ( not comparing year for year) and it was probably more the drivers driving style that won between the two. Nothing has yet reached 12v Cummins status for reliability when comparing stock engines (good power and bullet proof) not even the 24v or the CR 24v. This is debatable however if you factor in power levels of the the newer engines and everything save the old IDI's are newer.

"-GM
Quick, Allison tranny is very stout when truck is stock, or near stock, "

The Allison is most durable and has the best self protection software IMO, but not the quickest to shift. Therefore awesome for towing not the best for drag racing.

"CONS:
-Ford
On 03+ you have to pull cab to change headgasket, V8 not the best fuel mileage, good luck finding a stamdard trans, expensive parts"

Having to pull the cab is a engineering team needing their faces smacked. I still find it gut wrenching that they did that. Since the 7.3 was retired Ford has yet to put out an okay motor in stock form. I am watching the 6.7 though and they seem to be redeeming Ford. Time will tell. You can leave the cab on to work on the new 6.7 and yes it was a selling point the dealer pointed out.

"-Dodge
Stock auto can't handle much power, 24 valve lift pumps need to be upgraded asap to an airdog or fass pump ($400), Dash always cracks, no crew cab until 03."

Built Dodge auto as said above is bullet proof also it is currently in the fastest diesel drag truck behind a duramax. Depends on the year as to needing to upgrade the lift pump. 03-04 yes 05 on maybe your choice.

"-GM
IFS, Allison tranny won't handle a lot of power (defueling trans), V8 mpg, weak when towing (personal experience), cheap interior, expensive, hard to work on."

IFS can be made stouter mostly by upgrading the steering. The 5 speeds Allison could hold into the 800-900 ft-lb in overdrive and well over 1000 ft-lb in all 4 lower gears. This makes a lot of power relative, based on my 6.2l the Allison can hold over 3.3 times its output in overdrive and about twice what the old Cummins 12v put out stock. The Allison 1000 can be built to hold about any power level it just won't be the fastest to shift through the gears. As of 2010 the Duramax/Allison is the fastest up Eisenhower tunnel and it uses the least fuel doing it, it is also the fastest to stop with a load.

Personal experience I could out pull both Ford and Dodge up the passes loaded with about the same weight. Note I said up on flat ground it did seem a bit slower to accelerate when in a passing situation. Ask bftank I would let him pass going down the hills in his 7.3 and then I would pass him going up the next one, but we were well matched on flat ground.

I can vouch for the Duramax being hard to work on if you have doubts look up how to change the water pump.


Boiled down all the diesel's in stock form mechanically will outlast the truck they came in. The newer CR injection systems do not seem to be as reliable as the older systems. All the newer auto tranny's are strong and between them getting stronger and emissions getting tighter they have pushed manuals into the past. The chassis will always be the weakest link.