Hey guys, so the past few weeks I've been on a hunt for a diesel truck...the one that caught my interest today is an 02 f350 super cab with 220000 miles, and has some issues I might be willing to deal with..after hearing out some opinions. the main issue is the truck overheats after driving about 20 minutes. The water pump is the only thing he tried to replace, but disnt help He also says after it overheats, the fluid is gone from the radiator. It doesn't leak out anywhere, there's no oil in the radiator, or water in the oil. It does not smoke at all from the tail pipe.
What do you guys think could be causing this issue?
Tia

 

If its not leaking ANYWHERE (and this included places you cant see, like slow leaks into the the cylinder, but you say no smoke), then I would suspect its boiling and evaporating, but for coolant thats a big feat. I'm not sure of the boiling point of the coolant but I bet if the system lost all pressure it could do it.

If the cooling system is having problems it could be a make or break thing, they can be easy to fix or the end of the world.

 

The pressure cap on a cooling system is the key to raising the boiling point of the 50/50 mix of antifreeze and distilled water. For every pound of pressure cap rating the boiling of point of the above mixture raises 3 degrees. If you had plain water in your cooling system with a 15 pound pressure cap the water would boil @ 257 degrees. If you had a 50/50 mix of antifreeze and water the coolant would boil @ 265 degrees with a 15 pound cap. The boiling point would raise to 270 degrees if you had a 60% antifreeze mixture with a 15 pound cap. If you had a 70% mixture the boiling point would raise to 276 drgrees.

Don't be fooled by the old wives tail that by adding a richer antifreeze mixture will keep the complete system cooler. In fact it works just the opposite. As you know pure antifreeze has a higher viscosity rating than plain distilled water. * The higher the antifreeze mixture percentage its ability to adsorb heat from the engine goes down. *The higher the antifreeze mixture percentage also retards the radiator's ability to get rid of the coolant heat.

Race cars use pure water in their cooling systems because it adsorbs heat from the engine and gets rid if it in the radiator *better than any antifreeze mixture.

It's to your cooling systems advantage to mix your pure antifreeze/water mixture to protect the engine from freezeing 10 degrees lower than last years coldest day last winter.

Pure antifreeze boils @ 387 degrees Farenheit in atmosphere.

 

Whatever the case may be, bud..i'm sure theres better 7.3'z out there. I'd walk from that one

 

Well, the reason this caught my attention is because he only wants 3k for it...
Leather interior in really good shape, new starter, batteries, new ac compressor, all fluids have just been changed...

 

But theirs still that problem of new coolant every 20 mins.

Id say walk away from it. It could be 25.00 fix or it could be a new engine

 

I passed up on this one guys, thanks for the help....
There was also a can of worms with DMV too....

On too the next one!!