please help over heated

[namberly]

I have a 85 with a newly rebuilt 4.2L. sence the rebuild it has been running hot and I am unable to determine why. It has a new thermostat, water pump, fan clutch, and the radiator has been redone. if it is cool out side 60 or less it wont over heat but runs in the upper part of normal. 70 or above it will heat up with about 7 - 10 miles. any ideas??????

[fj157]

have you thought of a fan shroud (spelling?) it will make a huge difference make one out of card board and duct tape to see if it makes a difference and if it works make one out of sheet metal
(i know the card board sounds ghetto but it is cheap to fab and will save you money on making one if it dont work)

[cruiseroutfit]

Who did the rebuild?

Does it run fine (or is timing an issue)?

Did you change anything else at the same time (bumper, winch, etc)?

[namberly]

I did the rebuild I have only 20 years in turnning wrenches. I have also replace the fan clutch, thermostat, water pump, and had the radiator roded. the fan shourd is in tacked but the fan only sits about 1/3rd inside the shourd. this is normal from what I have been told. the engine run fine other than the over heating problem.

[fj40fax]

I had similar symptoms on my 40 a year or so ago. It turned out to be a pinhole leak in my radiator. It didn't even show wetness anywhere, but the loss of pressure let it heat up. The only sign I had was minimal loss of coolant over long periods of time. Changed out to a new rad, and all was good.

Fax

[mep1811]

I have had some overheating issues and have found out the following:

Use a OEM fan clutch. I kept overheating when I had aftermarket fan clutches . I kept swapping them out. I finally got disgusted and ordered an OEM unit no problems.

The other problem popped up when I changed water pumps. I changed them a couple of times and finally got an OEM pump. I compaired them and the OEM pump has a bigger impeller and sits deeper inside the block.

Hope this helps

Mike El Paso TLCA 8009
1985 FJ-60