Ok, this has probably been covered in another thread, but I've got a serious overheating problem. First the details. I have a 1992 Ford F-250 with a 351 Windsor bored .030 over, factory E-7 heads shaved .010, a new Spectra Performance heavy duty radiator, a new GMB part #125-1670P high volume water pump, a Hayden part #2783 severe duty fan clutch, and Comp Cams part #35-255-5 cam and matching lifters. When I had the heads shaved they checked them and said they were fine, plus I have no anti-freeze and oil mixture. I've tried multiple diffent thermostats of different name brand and designed usage, and I've tried changing the head gaskets 2x's. The weird thing is that most of the normal overheating symptoms like slow to turn over while starting, anti-freeze boiling, and so on are not happening. What's weirder is that my temp gauge is going all the way to hot while at driving rpm, but rev it a bit and it drops to the low side of normal. It also don't get hot while sitting at idle, just while driving it. I would almost think my temp sensor was bad except it's new too, and the radiator hoses are getting really hot. I got tired of messing with it before and just pulled the thermostat and drove it like that for 5 years with no problem, but I decided that I wanted heat this winter and here we are. So, any suggestions? I'm mainly wondering if the performance water pump and/or the performance fan clutch may have something to do with it.

 

WAG, but just to be eliminate, in cases of mysterious overheating make sure the exhaust and cats are not plugged and have no restrictions.

 

They're fairly new too, I bought all the exaust stuff at the same time that I bought everything else, and it's done this since the first time that I put it together.

 

2 questions...

1. Is the water pump going right direction?

2. Are the head gaskets on correct?

I have seen and heard of the head gaskets being put on backwards and this happening.

 

Probably OK there then.

 

#2

My bet is on head gasket(s) installed upside down or front to back.
Seen this more than once.

 

Ditto. BTDT. Once. Thats a sucky mistake to realize.

 

I double checked on this one, looked it up online because the Fel-Pro gaskets are funky. Turns out to get them both facing the front the way they have to be you have to put them on blue side up on one and black side up on the other. That's what I thought that I had done wrong on the first time I put the heads on, that's why I went to all the trouble to change them, but they both are facing front the way they are supposed to be.

 

Also, as far as the water pump direction, it's a high volume that was the listed part on Summit's web site, so it should be right. I looked up my exact truck and motor combo, and my truck has the factory original motor, and that's what it called for.

 

The only thing that I can think of is the fan clutch. I bought one that's used for racing thinking that it would keep it cooler, but the only time my engine is trying to get hot is driving down the road at highway speed. It will idle all day long and never get hot and if you rev it up when it's getting hot it will cool all the way down to normal. I was just hoping someone knew for sure before I went out and bought a stock one or just a solid fan for it.

 

Even if you didn't have the mechanical fan, if your driving down the road, it will cool off, unless the radiator is plugged. I've driving without the mechanical fan many times and the engine always got cooler when just cruising. When I stopped at the stop light, I had to watch it, or it would heat up.

 

X2

Your symptoms are the opposite of a bad fan/clutch.

 

Factory temp gauge or aftermarket?