got an 89 7.3 idi , i changed the readiator and the thermostat and the cool and put in additive and changed the hoses and the darn thing keeps geetin hot to the point of overheating but i catch it and pul over and let it cool down....theres no no oil in the coolant or vice versa and no leaks or seepage.....i just cant figure it out???????????

 

lack over air flow form

 

see is the condenser is clogged or fins bent over.

waterpump?


clogged water passage?

faulty gauge?

 

Waterpump impeller?

 

Is the fan clutch locking up when it gets warm?

You should notice a big increase in fan noise as coolant temp goes over 210 degrees.

 

Did you use a Ford or IH thermostat?

-Enjoy
fh : )_~

 

no fan noise used over counter thermostat, gauge is good when it says too hot its too hot it boils over into the overflow, of all these sugestions which is the easiest or which should i do first and how are ways to test them?

 

You need to use a Ford or IH thermostat, Only!

-Enjoy
fh : )_~

 

oh i see ok could that cause this situation

 

Yes, It's been known to.

If you wait a bit I'm sure others will pipe in on the matter, I don't know the details for sure but it has something to do with an internal bypass IIRC.

-Enjoy
fh : )_~

 

Most people that use parts house thermostats have nothing but trouble with them.

I say most because there have been a few that said otherwise, but they are a very small minority.

Ford or International only is the best option.

The Ford or IH thermostat does not have an internal bypass.
Also there is a check valve ball in the thermostat housing that must be free to move when you change the thermostat.
That helps with bleeding air out of the system when you refill the coolant.

If you don't hear the fan roaring when the engine is overheating and the engine RPM is high, then you also have a fan clutch that is not locking up.

 

i have a 1988 extracab longbox 2wd 7.3 idi, hypermax turbo, turned up injectorpump, c-6, dual range overdrive, and a 44gallon REAR tank, 17 gal front,3.55 gears, i haul Everything, new waterpump, radiator, and 190 thermostat, and it still overheats, i can drive down the road, 220-30 i stop it boils over, i am at a loss, i drive 75-150 miles a day minimum, with my work tools, at 65-70mph, egts are 700-900, depending on uphill or down hill HELP HELP

 

I have a 91 with a late 6.9 and it has never overheated, until recently. I suspect i have fan clutch problems, but I also think I may have poor circulation in the radiator. I suppose several of us have overheating problems.

 

there is one brand of thermostat that you can use that dont come from ford or ih but i cant remember the brand

 

make sure the fanbelt pulling the water pump is tight. I had a ford backhoe running hot, thought it was the radiator, when I replaced the altenator I found the belt was hard and loose. new belt on tight and the problem disappeared.

guess what, I'm going to check the belts on my truck tomorrow.