Hey guys, I need some advice....

I have a 77 F350 crew cab with a 460. The truck has 74,000 original miles, new four-row radiator, new fan clutch, 180 degree thermostat, automatic trans (with two external coolers) and being in Texas, it has A/C. This month has been the typical Texas summer with highs in the low 100's. The truck, without load, has at times been reading between the "M" and the "P" in the TEMP gauge. It generally stays on the "E".

Last week, I was pulling my fifth wheel camper and the needle almost hit the "H". Coolant was spurting out the overflow and I shut off the engine. I let it cool for about five minutes and it fired right up without hesitation. That day it was hot, well over 100 degrees, I turned off the A/C and as long as I didn't get over 50 MPH, the needle stayed right on the "P". If I was going up hill or got over 50 MPH, the needle rose toward the "H". I did spray some water through the radiator and it did show a decrease on the gauge.

Then on the return trip two days later, I drove home 60-65 MPH, up and down hills with the A/C on and the needle stayed between the "M" and the "P"???

Any suggetions??

Thanks, John

 

Sounds if you thermostat is begining to fail change out the tstat and that should be ok and also check the air fuel mixture that will also cause high engine temps..

 

Thanks Jack, I will give that a try. Should I go back with a 180 or try a 160?


Thanks, John

 

John,

Do you have a fan shroud to maximize airflow through the radiator? How about the engine timing? Are the timing chain and gears original or have they been replaced? As jack01 indicated could be your thermostat is beginning to go but you might want to think about adding an external engine oil cooler as well. I added one on my 82 E-250 460 and it made a big difference. Get the biggest oil cooler you can mount and make sure it has the built in thermostat for bypassing the cooler if oil temps are below a set temperature like about 180 degrees for winter use.

John

 

Forgot to add. Where did you get that new fan clutch? I replaced mine with different ones from Autozone, Pep boys, etc., but none seemed to work as well as the one from Ford that is part of the super cooling package.

John

 

Yes, it still has the original fan shroud, the fan clutch was from Ford. The engine was rebuilt by a friend who is a perfectionist and loves original Ford parts, so all parts except the usual (rods, crank, heads, etc) were new Ford. This same friend recommended I put a secondary trans cooler in. The tranmission is now cooled by the radiator, a factory trans cooler and now a second seperate cooler. I was also wondering, with two coolers, should I cut out the radiator trans cooler?

Where do you get an engine oil cooler with a built in thermostat? I'll go get one of those, it certainly sounds like it can help.
Thanks, John

 

John,

My oil cooler was a Hayden and you should be able to get one at Camping World or some other RV parts supplier. Also, you might check with Ford to see what they have. I would not remove the radiator cooler from the system since without it you might have problems with winter driving. Also, that plate in coolant cooler is probably the most efficient of the coolers you have. Given that the engine has been rebuilt how many miles on the rebuild? The reason for my question is that maybe the engine is still a little tight. Make sure about the engine timing, my FIL had the same problem with his F-150 460 after a rebuild. Timing was retarded and after resetting it to the factory spec (8 degrees BTDC) it was fine.

John

 

The truck has about 5K miles since the rebuild a little over a year ago. I only drive the truck on my days off so it is rarely used. My friend has the truck right now at his shop and just drove it with a car hauler attached, of course, it ran great and was only running in the middle of the Temp gauge. He measured the temperature with a infrared temp gun and found the upper tank and upper radiator hose temp to be between 185 and 188 degrees. I guess I have to drive it to get it to run hot! I will check the timing and swing by Camper World to buy the engine oil cooler.

Thanks, John

 

i agree iwth the other posts about checking the timeing, also check the fuel mixture

 

I'm wondering about the fan clutch. Do you hear it kick in? They are normally very loud on the 460's. On my RV (an 88 though), it roars when it kicks in.