Ford 460 motorhome running hot

maillemaker wrote:
I just went through an overheat problem with my E350 RV with 460.

My radiator looked like Yellowstone National Park inside. When it's cool, pull the radiator cap and look inside with a flashlight. You may need to drain off some coolant to be able to see the tops of the core tubes (assuming your radiator is a top-to-bottom cored radiator). On mine, there was a mineral deposit around all the cores, and many of the cores were partially or fully plugged. This was the cause of my overheat.



Unfortunately we were on a long trip (600 miles) and we limped it home at 50 MPH with the temperature gauge very near the high end all the way home.

I am pretty sure this cooked my PIP sensor, my Engine Temperature Sensor, and my Catalytic converter, which all failed in short order after this.

The fix for the overheat was a new radiator. I put in an aluminum one. You can see a thread on my repair here:

https://www.ford-trucks.com/forums/1543596-suggest-a-radiator.html

Aluminum radiators have superior heat transfer properties but are susceptible to galvanic corrosion, so I recommend using a zinc sacrificial anode with one. There are details on this in the above thread.

As part of this, I installed a dual temperature gauge to monitor the coolant temperature and transmission fluid temperature.

My engine temperature is now rock-steady at 188-195F.

As a result of this, I am a believer in using only distilled water with a radiator.

Also, I tried two flushes of radiator flush. This did nothing and I do not believe it can attack sediment issues. Waste of money.

I considered having the radiator "rodded out" but it is very hard to find shops anymore that can actually rod out or re-core radiators. And even if you do, there is the risk that the thin metal somewhere will start leaking anyway. If your radiator is original, it's 31 years old so it's probably best to replace it (if it is the problem).

Another thing to check is your fan. If it's thermal clutch controlled it could be bad. Check YouTube for how to do this.

Also check your lower radiator hose to make sure it is not collapsing when the engine revs. If so, this will cause a flow restriction.

If you have to run in an emergency and you have engine heat in the RV house turn it on full blast. This is a secondary radiator and will dump some heat into the house. Of course the house will be hot as hell back there so open your roof vents.

Steve

Hey thanks for the great info!! I will check into the radiator this evening and see if I can see deposits. I will also look into your other thread and see what the process is. This is still a possibility I have not fully ruled out.