Over heating at idle



I have an 89 Ford F-250 that I transplanted a 1978 Lincoln 460 into it, put in a brand new 4 row crossflow radiator, new 180 degree thermostat, new hoses, new water pump, I even put a 10" pusher electric fan on the front, and a new severe duty fan clutch with factory fan and factory shroud, put in a bottle of “Water wetter” and it still over heats if I am stuck in traffic with or without the A/C on, does fine running down the road. I did a complete build on the engine, but it did this before I built it, as I ran it a year in the truck before I did the complete build. I have tried to bump my idle speed up a little, but then it diesels when I shut it off, even tried to go to higher octane gas with same result. I have put 4 fan clutches on it, even went to a solid drive flex fan, that was a waste of money. If anyone has any ideas that could help me I would appreciate it.


The fan shroud is in place isn’t it?

Are you sure the vehicle is overheating?
Any boiling over, etc.?

Any chance the temp sending unit for the gauge is not compatible with that gauge and the reading is in error?


sounds like your running to rich.


How are the hoses. A defective hose can block coolant flow and the defect can be internal and not visible from the outside.

It also could be be a old radiator that is just too clogged up.

What temperature thermostat is specified by Ford for this truck Using a lower temperature thermostat does not increase cooling capacity, it only lowers the operation temperature and that is not good for the engine.


When it is overheating, check the lower radiator hose, and see if it is collapsing. This is just a wag, but with that much air running through the radiator, the coolant should be cooling just fine. Also, are you sure the electric fan is running in the correct direction? I’m sure you checked it, but trying to help.


Fan shroud is in place and fan blades proper space in the shroud opening. Temp gauage is working proper, I even put in a second Auto Meter from Summit Racing and mounted it to steering column to make sure, it’s going up to about 215, as far as boiling over… if it is then it’s just pushing it into the overflow tank and then sucking it back in as it cools.


Tried adjusting the idle mixture screws both ways, to make it a little more lean and a little more rich, din’t make any difference other than the quality of idle smoothness.


Hi Joseph:… in my question it says “brand new 4 row radiator, new hoses, new water pump and new 180 degree thermostat” and this engine is from a 1978 car, this engine runs on a 180 not a 195, I did try a 195 and that just made matters worse.


I wnat to thank you for the “wag”… the lower hose is not colapsing, I have good coolant flow, and yes the electric fan is pushing LOL I know that could be something easy to overlook, but yes it’s going the right way… I have covered all the base’s that I know and am at my rope’s end… everything under the hood is new and the shroud is from Ford ordered for that truck with a 460 in it, I am running factory fan with severe duty clutch, the only thing I have not tried yet is going up on the octane, so I guess that’s the next step. Thanks


Could the water pump be rotating in the wrong direction? When you replaced the water pump, are you getting the one for your original year engine or the new engine? I don’t know if there is any difference but just another “wag.”


all the 460’s rotate clockwise or standard rotation and yes it is rotating the correct way… see what I mean, this is totally baffeling me too. The smaller 5.0 and 5.8 had a reverse rotation water pump, but these run standard.