# 7.3 Diesel Won't Run Right



## sgtusmc98

Have a question, got a 2002 f350 with the 7.3 diesel, wouldn't run worth a flip at -8. Any cures? Idled fine but lost power after driving, some of you all live in much colder places, block radiator with something?


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## LincTex

Likely wax crystals built up in the fuel filter, 
often called "diesel gelling".

Add some Howe's - they have a guarantee on the bottle that if the fuel is treated per instructions, they will pay for your tow charges if your fuel "gels".


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## LincTex

sgtusmc98 said:


> Have a question, got a 2002 f350 with the 7.3 diesel, wouldn't run worth a flip at -8. Any cures? Idled fine but lost power after driving, some of you all live in much colder places, block radiator with something?


Yes, definitely cut down on the airflow going through the engine compartment. Try a piece of cardboard over the radiator itself - only block about 3/4 of the area. WATCH your temp gauge. On my Cummins, I can block about 95% and still not overheat.


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## UncleJoe

I moved this from a weather thread to it's own topic.

I have the 5.9 Cummins. As with any diesel, it doesn't run for crap until it's warmed up. We rarely get temps this cold. I doubt it would even start right now since I don't have it plugged in.

Something I've noticed over the years is when I have the snow plow on, it warms up fast. Without it, not so much. So blocking some of the airflow definitely makes a difference. But I don't think I'd completely block the radiator. Maybe someone else has more experience with it than I do.


Edit.

I see others have chimed in while I got pulled away.


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## NaeKid

sgtusmc98 said:


> Have a question, got a 2002 f350 with the 7.3 diesel, wouldn't run worth a flip at -8. Any cures? Idled fine but lost power after driving, some of you all live in much colder places, block radiator with something?


Beyond the cardboard trick - I have also used some off-cuts of carpet as well between the grill and radiator, change out the anti-freeze thermostat to something that will allow the engine to run significantly warmer, flush out "summer" anti-freeze and replace with with anti-freeze that is rated down to about -45° ... install a fuel-warmer ... install an oil-warmer-style block-heater, install a circulating blockwarmer (for antifreeze) ...

Lots of options - don't need to do all of them, but, if some are done it could also help significantly.


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## Tirediron

If you "gelled" the fuel in the filter, that filter needs to be changed, gelling is the heavier paraffin in separating out of the fuel and clovering the media with basicly wax, this wax won't wash thru very easily. I run summer diesel year round and add the howes lubricator that Linctex recommended. 
Add the howes, if the truck will still idle let it run for 15 minutes, change the filter. you can cover the front of the rad, preferably in front of the grill, so that some air can flow.


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## sgtusmc98

I appreciate all the input this is my first diesel but it is very important to us since it is our only 4x4 I have blocked radiators before but didn't think about it at the time for some reason, I have never heard of the additive Howe's though, I will try and pick up some, thanks!


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## Tirediron

Almost any truck stop should have some kind of diesel fuel conditioner, I prefer howes because of the lubricity additive


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## LincTex

Tirediron said:


> Almost any truck stop should have some kind of diesel fuel conditioner, I prefer howes because of the lubricity additive


I used to make a flatbed run to Hamilton, Ontario every 5 days picking up stainless steel; ran Howe's any time it got under 15*F outside. It's all you will find truckers using. It's also available at most farm supply stores.

It used to be a gallon of unleaded gas in the tank would do the same trick (keep wax crystals from forming) but its so dang hard to find any without alcohol in it nowadays (which is supposed to be hard on IP's). Some Diesel fuel additives actually contain alcohol (including sea Foam) so I dunno anymore.... :dunno: . :dunno: . :dunno:


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## Tirediron

I use Howes in my detroit, cat, & Johndeere diesels, Our fuel is seasonally adjusted, but I got tired of running winter fuel in summer if I bought too much, So I just fill my bulk tanks with the last run of summer fuel and treat it with howes, I have also used kleen flo , but it doesn't have the added lubricity.


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## Meerkat

If this 'global warming' the inventor of the web warned us about keeps up I may need some of that down here in Florida. Record breaking cold weather but Shorty is still doing fine, knock on wood!


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## OldCootHillbilly

Fuel additive fer sure. Ifin yer gonna block the radiator, be sure an cut a round hole in the cardboard where the center a the fan blade be. Don't know bout them newer fan blades, but the older ones would tend ta crack er break ifin they flexed all the time from only part a the radiator blocked.

Block heaters er nice but a buddy a mine be a mechanic an says some a em they been puttin in be leakin. He's switched over ta the tank/pump style. Round these parts they've switched ta the winter blended fuel, but I always put in a additive. Don't like bein stranded. 

Also, I put battery maintainers on my 7.3 that was hooked upta the engine warmer. Ever time I plugged it in it topped off the batteries to.


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## ihaveMANHIDE

If you are having trouble starting it. Before you try an crank it. Turn the key towards you to prime the glow plugs. And maybe put a blanket over you radiator and engine block so the water doesnt freeze an crack the block. My brother is a certified diesel mechanic. Any more questions. Feel free to send a msg or quote me. Best of luck to ya


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## LincTex

ihaveMANHIDE said:


> put a blanket over you radiator and engine block so the water doesn't freeze an crack the block.


Only a fool would run straight water in the radiator.

There's NO excuse to not run the proper propylene glycol antifreeze solution.


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## helicopter5472

I used to have a Chevrolet diesel, I live in Maine and when it was really cold I would turn the key on to heat the glow plugs as soon as the light went out I would repeat again and sometimes a third time. The system is timed, and by repeating this a few times heated them better and made starting it much easier. I'm not sure if your Ford is designed in a similar way. Using fuel conditioner is recommended. Not recommended is the poor mans fuel conditioner is adding a gallon of gas to 20 gallons of diesel, but works in a pinch.


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## ihaveMANHIDE

LincTex said:


> Only a fool would run straight water in the radiator.
> 
> There's NO excuse to not run the proper propylene glycol antifreeze solution.


I flush my radiator every month. But i usually run 50/50


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## LincTex

ihaveMANHIDE said:


> I flush my radiator every month. But i usually run 50/50


Every month?!?!?!!?!?!

Your posts are making me rapidly believe you know _*very little*_ about vehicles.


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## ihaveMANHIDE

LincTex said:


> Every month?!?!?!!?!?!
> 
> Your posts are making me rapidly believe you know very little about vehicles.


Yes sir every month. Im OCD about preventative maintenance on my vehicles. Especially when they are used everyday pulling 20,000 pounds +. I know my fair share to get by. Mostly about older American made trucks. No our of country brands. 
I replace the head studs, and the injectors in all of my Ford 6.0s about every 3 to 6 months at the most. It gets costly but they never give me any problems


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## LincTex

ihaveMANHIDE said:


> I replace the head studs, and the injectors in all of my Ford 6.0s about every 3 to 6 months at the most. It gets costly but they never give me any problems


Costly isn't even the right word!!!! For that much money (ARP studs don't need to be replaced, BTW) you should just trade in every 12 months!!!

ARP studs for 6.0 (just the studs only) are $450-$550
Injectors for 6.0 Powerstroke run about $1200 (cheap ones) to $2000 for all eight of them.

*Every 3 months* means you would spend over *$10,000 per year* on studs and injectors.


That's absolutely nuts!! I can't imagine ANYONE would ever do that. (In fact, it would be cheaper to just swap the entire engine every 12 months)

If that was what was required to keep a 6.0 running, no one would own one!! The would have sold their junk and bought a Cummins or DuraMax long before spending that kind of money to keep a 6.0 running!


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## Tirediron

Wow this thread has come off the rails, from how to deal with gelling fuel to quarterly head stud changes in a FoMoCo money pit. 
I'll stick to my 6.5T mechanical that just needs filters and oil changes or if I need to pull a load my Peterbilt with a real engine


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## LincTex

Tirediron said:


> Wow this thread has come off the rails, .... quarterly head stud changes in a FoMoCo money pit. I'll stick to my 6.5T mechanical


LOL!

6.9, 7.3 and 7.3 PowerStroke = reliable, sought after engines

6.0 PowerStroke = WTF were they thinking!!!


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## Magus

ihaveMANHIDE said:


> If you are having trouble starting it. Before you try an crank it. Turn the key towards you to prime the glow plugs. And maybe put a blanket over you radiator and engine block so the water doesnt freeze an crack the block. My brother is a certified diesel mechanic. Any more questions. Feel free to send a msg or quote me. Best of luck to ya





ihaveMANHIDE said:


> I flush my radiator every month. But i usually run 50/50





ihaveMANHIDE said:


> Yes sir every month. Im OCD about preventative maintenance on my vehicles. Especially when they are used everyday pulling 20,000 pounds +. I know my fair share to get by. Mostly about older American made trucks. No our of country brands.
> I replace the head studs, and the injectors in all of my Ford 6.0s about every 3 to 6 months at the most. It gets costly but they never give me any problems


Wow...just f**king WOW.
You really had us going kid, but won't your dad be pissed if he finds you up this late?


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## Grimm

LincTex said:


> Costly isn't even the right word!!!! ...
> *Every 3 months* means you would spend over *$10,000 per year* on studs and injectors.


That is how much the new car K bought cost!


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## LincTex

Grimm said:


> That is how much the new car K bought cost!


Just to bring you up to speed, Grimm...

Powerstroke 6.0's leave the factory with TTY (torque-to-yield) head bolts, which can only be used once. They didn't do a good job of clamping the heads (result: blown head gaskets), so most folks just replace them with ARP studs - a ONE TIME expense... they can be reused nearly forever. Once you spend the $500 for them, you NEVER have to buy new ones again... and you really should not need to replace the head gaskets again, either.

Injectors will last longer than 3-6 months. It's a hell of a job to do on a 6.0 (well, any job to do on a 6.0 is hell), so most folks won't do it until it NEEDS to be done. A lot of 6.0 work requires removing the cab from the truck!

Yes, the coolant in the 6.0's needs replacement more often, but NOT every 30 days!!!!!

A "blanket" will NOT protect against freezing a block if it gets too cold outside.
A blanket isn't capable of generating any heat on its own!


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## ihaveMANHIDE

LincTex said:


> Costly isn't even the right word!!!! For that much money (ARP studs don't need to be replaced, BTW) you should just trade in every 12 months!!!
> 
> ARP studs for 6.0 (just the studs only) are $450-$550
> Injectors for 6.0 Powerstroke run about $1200 (cheap ones) to $2000 for all eight of them.
> 
> Every 3 months means you would spend over $10,000 per year on studs and injectors.
> 
> That's absolutely nuts!! I can't imagine ANYONE would ever do that. (In fact, it would be cheaper to just swap the entire engine every 12 months)
> 
> If that was what was required to keep a 6.0 running, no one would own one!! The would have sold their junk and bought a Cummins or DuraMax long before spending that kind of money to keep a 6.0 running!


Its all a tax write off bud. And yeah its kind of insane. Im not the one paying for it. I just manage everyone. And thats just the 6.0s. The 12v cummins we have is probably the most well kept ones we have that has just over 650k miles.


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## ihaveMANHIDE

Magus said:


> Wow...just f**king WOW.
> You really had us going kid, but won't your dad be pissed if he finds you up this late?


Lol shut up kid. I dont base my life around my trucks. I may have exaggerated on the time period between maintenance. Lol calm your tits


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## LincTex

ihaveMANHIDE said:


> Lol shut up kid. I don't base my life around my trucks. I may have exaggerated on the time period between maintenance. Lol calm your tits


......................and here it comes!!


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## UncleJoe

LincTex said:


> ......................and here it comes!!


No it doesn't. We're done here.


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