'97 F350 7.3L needing some love

[scotts90ranger]

I asked on a different forum (not a truck forum...) and got some negative nancy's...

Anywho, '97 F350 crew cab long bed 4x4 single rear wheel manual transmission 35" tires and 4.10:1 gears. The thing has been around, chassis has over 350k on the clock (but the speedo/odo stops ocasionally so who knows... that's another deal that I think I know the fix just haven't gotten to it) and according to the previous owner the engine is supposed to have around 250k on it. From what I've heard the injectors are supposed to last about 200k, and one sign of bad injectors is smoke on a cold start and there's plenty of that sometimes. When I got it it had a Spectra air filter on it, I upgraded to the Napa Cummins filter but probably not soon enough to save the turbo... It runs smooth and hot starts are instantaneous, no codes, only seems gutless when the total weight is over 12k pounds . The exhaust is 3" down pipe and 4" straight pipe dumped before the rear tire. The warmup valve on the turbo is bypassed.

When towing it gets hot, and on extended pulls uphill I have to back out of it to keep it cool (starts defueling around the L in NORMAL I believe so I keep it at the A or lower) which with 12k pounds or more means 38mph up the mountain passes in spots (third gear 2500rpm). Currently it won't pull 4th if I could get there but the 800rpm or so jump from 3rd to 4th is a killer, 2500rpm or so in 3rd to 1700rpm in 4th. The thing builds about 3psi boost before 2000rpm and peaks at 15psi at 3000rpm, absolutely no smoke.

Ok, with that said, I have a Mishimoto radiator on the way as well as a Gates water pump so that should hopefully help the cooling issues, I replaced the fan clutch a couple months ago. I have a early 99 intake spider and an all aluminum '01 intercooler that all I need is some exhaust tubing and time to install. For injectors I'm looking at Full Force 180cc with a Hydra and Jellibuilt tunes and a reworked high pressure oil pump. Toying with rebuilding the turbo with KS replacement wheels while in there, the pedestal needs resealed anyway. I don't need to be the fastest thing out there, I just want to be able to do 50 up the mountain passes with 20k pounds total weight for another 100-150k miles... All of the above parts cost very similar to stock components so might as well get a little extra.

Does this sound like a reasonable plan? I know a clutch is going to be needed with that which is fine, it needs one anyway, Full Force has Motorcraft glow plugs for a $99 adder with injectors so will probably go that route. Rust belt people probably freak out about a high mileage old rig and throwing money at it but it's near rust free (no flakes, just mild surface rust).

 

[scotts90ranger]

Pretty sure I found my cooling issues today... I put the new Mashimoto radiator in and the new water pump, once I got the radiator out I noticed about 1/4 of it was plugged externally with mud/dirt, and some pretty nasty coolant goo was in the bottom. Flipped it over and ran the garden hose through it and it flowed pretty slow and a lot of the milky yellow mixture flowed out for several minutes... To top that off the thermostat was installed wrong, it should be under the gasket and it was over the gasket...

Flushed it with a few gallons of distilled water after I pulled the radiator and before I pulled the water pump, topped it off with fresh coolant, some "NAPA Cool" and distilled water... I don't have anything lined up that will test it's cooling capabilities since it was fairly specific on what it took to get it hot...

 

[Blmpkn]

Don't know too much about diesels, but that thing only makes 15 pounds of boost? Seems low.

Sounds like you've probably fixed the cooling issues, hopefully.


And as a rust belt person, I'm not opposed to putting money into a high mileage rig..just as long as its not completely effed.. And it "speaks" to me in some way.

 

[Curious Hound]

Those older 7.3's speak to me more sexy than my wife ever did.

 

[scotts90ranger]

I haven't driven the thing unloaded in a LONG time, I'm talking no trailer and nothing in the bed, it's pretty sporty for a 7400lb beast... I had to pay attention to speed as it accelerates a LOT faster than the '97 Ranger and has more snoot left at 60mph in 5th gear... it's downfalls must be turbo related and probably worn injectors too, it used to have a little more power...

That said, so far so good on the radiator, thermostat holds it to the same temperature it did before, the excavator I towed wasn't far or up any hills so no ideas how much better it works...

 

[scotts90ranger]

Ok, slight update after the first loaded drive with the new radiator, drove over the pass with just the camper so around 10k pounds and made it up the pass both directions at about 55mph and at night barely twitched the temp needle, in the heat of the day mid 80's I imagine I got almost as hot as it usually did but cooled off immediately after I took the power off...

On the trip over at about 6pm I smelled diesel worse than normal, and the fuel gauge went down about 1/4 in less than 10 miles... (rear tank, so like 4 gallons), made it to a rest area and a friend caught up, we did some diagnosis and it looked like fuel pump, got the replacement at about 11pm then started it up and still a huge leak, one of the fuel return soft lines from the head to the fuel bowl. Thought I had one so went home to find them, turns out they're at work, found some propane hose that was 1/4" and rated for 350psi... two clamps on each end and back on the road about 2:30am... made it to camp around 4:15am... it made it back and now I'll get some proper hydraulic hoses made

Anywho, with an intercooler there would probably be less heat buildup, and if the injection timing was better from bigger injectors and a tuner it might not get as hot... that and hopefully be able to handle an extra 6k pounds of cargo from where I was...

 

[Snoranger]

Ok, slight update after the first loaded drive with the new radiator, drove over the pass with just the camper so around 10k pounds and made it up the pass both directions at about 55mph and at night barely twitched the temp needle, in the heat of the day mid 80's I imagine I got almost as hot as it usually did but cooled off immediately after I took the power off...

On the trip over at about 6pm I smelled diesel worse than normal, and the fuel gauge went down about 1/4 in less than 10 miles... (rear tank, so like 4 gallons), made it to a rest area and a friend caught up, we did some diagnosis and it looked like fuel pump, got the replacement at about 11pm then started it up and still a huge leak, one of the fuel return soft lines from the head to the fuel bowl. Thought I had one so went home to find them, turns out they're at work, found some propane hose that was 1/4" and rated for 350psi... two clamps on each end and back on the road about 2:30am... made it to camp around 4:15am... it made it back and now I'll get some proper hydraulic hoses made

Anywho, with an intercooler there would probably be less heat buildup, and if the injection timing was better from bigger injectors and a tuner it might not get as hot... that and hopefully be able to handle an extra 6k pounds of cargo from where I was...

The intercooler will definitely help with the heat.
With a diesel... rich is hot, lean is cool*. Bigger injectors will make higher cylinder temps and higher EGTs. Upgrading the turbo will help cool it down.


*Within reason. You can dump enough fuel into a cylinder that it actually starts dropping the EGTs from the liquid fuel the exhaust.

 

[scotts90ranger]

That's actually what I was hoping for, shorter injector duration at the right time and less back pressure from the turbo working more efficiently should mean the engine doesn't have to work as hard to do the same thing... which from what I hear is the key for diesel's all around, get a bad ass diesel that can produce a bunch of horsepower but use as little as possible and you will use less fuel...

Roof should be going up on my shop in about 3 weeks, working on weekends in hot weather means slow work, and everyone I ask for help from is busy... so I should be able to have a productive winter!

 

[bilbo]

Those older 7.3's speak to me more sexy than my wife ever did.

This. So much this.

 

[scotts90ranger]

Ok, an update on the ol christmas tank...

I sunk about a grand into the ol girl the last couple months, rear shocks (I ordered front but haven't gotten them in yet), rear sway bar links and all bushings (it doesn't have a front for whatever reason), resealed the oil cooler and installed a brand friggin new Borg Warner turbo...

The turbo was somewhat of a game changer. The next time I drove over the pass with the Ranger and trailer it wasn't much better than before, and the last time it was no better if not a little worse than it'd been... with the new turbo the coolant temp sits at the N in Normal instead of R cruising at 55mph on flat ground and about 14k pounds (was towing the boat with the camper in the back) was able to hold 4th gear over the pass at like 2200rpm and 10psi, I didn't have to back out of the throttle for a long time... Now it's just to the normal low horsepower it is supposed to be .

The next trip is in October, I'll see if I can get the intercooler in by then... there's still a diesel leak somewhere but it isn't too bad so I'm going to ignore it for now...