7.3L Powerstroke or 5.9L Cummins with over 200k miles -- still lots of life, or not?

[Builder]

I would keep additives in the tank like biocides to keep critters from forming in your fuel. Hopefully, you can garage it. If you can't, park it over some well drained stone so the frame & sheetmetal don't wick-up moisture. Once a week, fire it up and use it to run an errand you'd normally use your car to run and that should help.

I wouldn't just turn it over and let it idle. Instead, take it out and run it. That way the tires get some rotation, the brakes get rust haze chopped off them, the turbo gets spooled-up and all the coolant passages get coolant blown thru them. I never liked the idea of just turning a diesel over and letting it idle-not all of the engine components get lubricated. Quite a few mechanics tell me that is not good for a diesel that sits a lot.

 

[Bill_C]

I've got the '94 7.3 Powerstroke (original owner) and for the last few years it's being driven maybe 3K a year, mostly to haul the travel trailer on vacation. Maybe once every month or so it'll get fired up to get plywood or maybe haul music gear out. Hasn't had any problems from sitting. Look carefully and I believe you can find a 94 to 97 with 150K miles without spending a fortune. I have read of many 7.3's going well over 300K, just gotta change the oil regularly. Note that the first Powerstrokes came out in late '94 so that year there was the direct-injection (DI) 7.3 Powerstroke, the indirect injection (IDI) non-turbo 7.3, and a turbo IDI 7.3. The IDI and the Powerstrokes are totally different engines: different blocks, cranks, etc.


I have the 4WD and believe its almost a necessity. I've been stuck with 2WD too many times, even in my own front yard once.

The early 7.3's had a couple of minor issues: the cam position sensor (CPS) was unreliable, now you can get 'em cheap ($30) from ebay. The fuel heater wire in the fuel bowl was useless, it'd short out and blow a main fuse (easy to bypass). The stock air intake was junk, an aftermarket version such as the Tymar flows and filters better for a little over $100.

The manuals had one major issue: the dual-mass flywheel wasn't one of Ford's better ideas. A South Bend clutch and flywheel will solve that for $600 to $900 if you do it yourself, depending on which hp level clutch you go with. The manuals also have a minor issue with the clutch pedal linkage bushing, a cheap plastic bushing wears and pops out, keeping the clutch pedal from working properly, but this is an easy fix also. Automatic transmissions (only available from 96 ? on) have their share of problems, they wouldn't hold up to the power.

The 7.3's can't get the big horsepower of some other motors, but a do-it-yourselfer can get lots more horsepower, reliably, without major outlays of cash. Replacing the downpipe helps lower EGT's and flows better. Several vendors specialize in chips for the Powerstrokes; I'm running Beans Diesel programming but Swamps, DP Tuner, and PHP have good programs too (most folks prefer these vendors to the "big-name" guys). A chip, downpipe, and intake will give more towing torque, lower EGT's and actually improve reliability for around $800 total and give you somewhere around 250 to 275 rear-wheel horsepower. (Note: you should get a pyro gauge to read EGT's even if you don't add a few more ponies)

Spend a few hundred dollars more and you can increase the flow of your injectors, getting over 300 RWHP. You can get over 400 RWHP for around $2.5K total (counting the chip, intake, and downpipe) with DIY Stage 2 injectors and a bigger oil pump. ('99 and later models won't need the bigger oil pump.)

 

[WH401]

I have both a 7.3 in an 01' Excursion and two 5.9's, one in a 92' Dodge and the other in an 06' Dodge. That said, the 7.3 has been a reliable power plant, but if I were looking for a vehicle over 200k, I would go for the 5.9 every time. The 5.9 is overkill in a light duty pickup, it's a medium duty engine in a light duty application. The 5.9, with the proper maintenance, will run twice fold the amount of time that a 7.3 would.

The 92' Has 170k on it and up until 2000, it only had 55k on the clock. From about 2000 - 2005, my father put 100k on it in 5 years. When he passed away I started driving it and have put the last 20k on it. I usually only drive it about 3 - 5k miles a year, one oil changes length of time. The 92' is an automatic and still has the original 518/46RH auto and it's spent the first 55k miles of it's life towing a 20'+ travel trailer while it's bed was loaded with probably 1000 - 1500lbs of cargo. The transmission surprising still works well, the only issue it that 2nd gear likes to stick when you get into a lot of stop and go traffic and the fluid gets a little warm. Also remember that that particular transmission doesn't have a locking torque converter, so it runs a little warmer than a newer one.

I don't let the 92' sit for more than a week most of the time, but I wouldn't be worried to let it sit longer. I tend to drive it more in the winter because the heat works fine, but the air conditioner too much of a load on the engine and the vent foam has started to deteriorate. It's definitely not the prettiest thing on the road, but it's dead reliable, and I wouldn't hesitate to take it on a long trip. It's only left me stranded once when the batteries needed to be replaced. Unfortunately I can't say the same about the 7.3, it's left us stranded 4 times in the last 4 years, albeit because of normal wear items, but still.

As far as fuel mileage, the 7.3 will do 20 on the highway, and about 15 - 16 around town, but it's 2wd though. Both of the 5.9's are 4wd and the 91' will do 20+ on the highway and 16 - 18 in mixed city/highway driving. The 06 will do about 16 in mixed driving, and 17 - 18, or possibly more but I haven't been able to check yet, on the highway. Personally, I think that's excellent for both of those trucks compared to 2wd vehicle that has much better aerodynamics.

Between both sides of the family there have been six 5.9 Cummins Dodges since 1989, 5 of which we still own. An 89', which is the only one that is not owned anymore, the 92', a 95', an 01', and two 06's. The 95' is a 5 speed and actually only has 90k on it, it has spent it's entire lift towing a 30+ ft 5th wheel camper. The 01' is an auto with about 48k on it, and has spent all of it's life towing in the same way that the 92' used to. Both the 06's are daily drivers that occasionally tow every once in a while.

The 7.3 is good, but it's not a 5.9, plain and simple. The 5.9 has been a good engine to us, as well as to many other people, and I would never hesitate to buy another one, or another Cummins at that.

 

[powerstroke444e]

Kills me to write this but I would look @ 1999-2002 dodge stuff with a stick & a 5.9L. as the motor will outlast a number of trucks. The 7.3L of the same vintage do take a little more work and cost more to work on as there are a lot more electonics in the ford than the dodge. You should be able to find a 100K truck in your price range but if need crew cab or auto with the ford, it will be a good truck also.
If it was me I would look for truck that came out of the south as there will be less rust, if you get luck & find a truck a snow bird had they have low hrs & miles.
Once you have a diesel it is very hard to tow with a gas burner know matter how much HP the gaser has.

 

[jas67]

I would keep additives in the tank like biocides to keep critters from forming in your fuel.

Does Powerservice do the job for this? If not, what additives do you recommend?

Hopefully, you can garage it. If you can't, park it over some well drained stone so the frame & sheetmetal don't wick-up moisture. Once a week, fire it up and use it to run an errand you'd normally use your car to run and that should help.

It'll be garaged, except when I need the extra space for projects, and then it will be parked on a well drained stone driveway.

I wouldn't just turn it over and let it idle. Instead, take it out and run it. That way the tires get some rotation, the brakes get rust haze chopped off them, the turbo gets spooled-up and all the coolant passages get coolant blown thru them. I never liked the idea of just turning a diesel over and letting it idle-not all of the engine components get lubricated. Quite a few mechanics tell me that is not good for a diesel that sits a lot.

The only reason that the Firebird gets the start and idle treatment in the winter, is I can't risk getting it exposed to salt, and it is only insured for road-use 9 months out of the year.

As for using it for occasional errands, I'm more likely to just drive it to work periodically, as my drive is 15 miles one way, it'll get more at-operating temp running that way, than if I use it to do the 2-3 mile trips around town.

 

[jas67]

The stock air intake was junk, an aftermarket version such as the Tymar flows and filters better for a little over $100.

Are you talking intake manifold, or air-filter housing, and tubes that feed air to the turbo?

The manuals had one major issue: the dual-mass flywheel wasn't one of Ford's better ideas. A South Bend clutch and flywheel will solve that for $600 to $900 if you do it yourself, depending on which hp level clutch you go with. The manuals also have a minor issue with the clutch pedal linkage bushing, a cheap plastic bushing wears and pops out, keeping the clutch pedal from working properly, but this is an easy fix also.

Ford isn't the only one to have done the dual-mass flywheel thing. I've driven BMW's for years (forget the yuppie reputation, rear wheel drive with independent suspension, excellent handling, and very smooth yet powerful inline 6-cyl. engines -- what's not to like), and they went to the dual-mass flywheels in the early 90's. My '94 325is now has an aftermarket aluminum flywheel and an M5 clutch -- much better.

Automatic transmissions (only available from 96 ? on) have their share of problems, they wouldn't hold up to the power.

The 7.3's can't get the big horsepower of some other motors, but a do-it-yourselfer can get lots more horsepower, reliably, without major outlays of cash. Replacing the downpipe helps lower EGT's and flows better. Several vendors specialize in chips for the Powerstrokes; I'm running Beans Diesel programming but Swamps, DP Tuner, and PHP have good programs too (most folks prefer these vendors to the "big-name" guys). A chip, downpipe, and intake will give more towing torque, lower EGT's and actually improve reliability for around $800 total and give you somewhere around 250 to 275 rear-wheel horsepower. (Note: you should get a pyro gauge to read EGT's even if you don't add a few more ponies)

Spend a few hundred dollars more and you can increase the flow of your injectors, getting over 300 RWHP. You can get over 400 RWHP for around $2.5K total (counting the chip, intake, and downpipe) with DIY Stage 2 injectors and a bigger oil pump. ('99 and later models won't need the bigger oil pump.)

Stock power will be fine for my needs. I will consider a chip for better fuel economy though. I had a non-turbo 6.2L diesel Chevy years back, and I know with that, larger exhaust was the key to better fuel economy and power (a turbo was even better, but more money). I would assume that a 4" exhaust would help with the Powerstroke (and the Cummins)?

 

[RobertN]

Interesting you mention this... My Grandfather used to rust out his exhaust because he did the 2 mile trips to the store once a week. Moisture in the exhaust would rot it out.

FWIW, that was one gasser truck that would really PULLLL. I have always been a Mopar, and to some extent, Ford guy. But that '69 GMC Camper Special would pull like a freight train. It was a 3/4 ton, with an odd factory 6" bed extension; it had a 8'6" bed for a camper. It also had a built for a truck 396 4bbl and Turbo-400, and some gears.

Interesting, cause my Uncle also had a '66 SS396 4spd Chevelle. That 396 looked different; intake, exhaust ect...

As for using it for occasional errands, I'm more likely to just drive it to work periodically, as my drive is 15 miles one way, it'll get more at-operating temp running that way, than if I use it to do the 2-3 mile trips around town.

 

[powerstroke444e]

I know with that, larger exhaust was the key to better fuel economy and power (a turbo was even better, but more money). I would assume that a 4" exhaust would help with the Powerstroke (and the Cummins)?

If nothing else they all sound better with 4" exhaust without a muffler.

 

[jayste]

Interesting you mention this... My Grandfather used to rust out his exhaust because he did the 2 mile trips to the store once a week. Moisture in the exhaust would rot it out.

FWIW, that was one gasser truck that would really PULLLL. I have always been a Mopar, and to some extent, Ford guy. But that '69 GMC Camper Special would pull like a freight train. It was a 3/4 ton, with an odd factory 6" bed extension; it had a 8'6" bed for a camper. It also had a built for a truck 396 4bbl and Turbo-400, and some gears.

Interesting, cause my Uncle also had a '66 SS396 4spd Chevelle. That 396 looked different; intake, exhaust ect...

Funny you should mention it I used to have the GMC version of this truck. They called it the Longhorn. It was a camper special with an 8'6" bed. This one had a 350 with 4spd trans. Not sure what rear it had.

 

[Bill_C]

Are you talking intake manifold, or air-filter housing, and tubes that feed air to the turbo?
QUOTE]

Specifically, the air filter and the tube that connects the air filter to the turbo. The stock Ford airbox leaked and there was a silent recall on them. For a diesel, I would not advise using foam filters; too much maintenance keeping 'em clean and oiled, plus too many horror stories of dirt getting past them and ruining turbos. A good pleated paper filter works great. The Tymar is a tube made for the 7.3 and uses a huge Donaldson 6637 pleated paper element.

The 7.3's connect from the exhaust manifold to the turbo inlet collector with a set of up-pipes. There are some high-dollar upgrades available there too...as well as bigger intake manifolds. For most of us, the cost/benefit ratio rules out goodies like that. And of course, there are goodies like upgraded turbos...and head studs...and pistons...the sky is the limit.

I've heard of 7.3's yielding over 800 hp on the dyno. There's even a common rail conversion being developed by at least one vendor. I'd say within a year or so we'll see the 7.3 break the magical 1000 hp mark. (My personal target is 400 hp, I'm only $900 short right now...)

For us mere mortals, I'd recommend the air intake, downpipe, and chip. For any diesel, I'd strongly recommend a EGT (pyro) gauge, mounted pre-turbo. A boost gauge is nice (measures the turbo's performance) but isn't critical IMHO.