My 300ci 6 hates being cold. When running, the OEM gauge usually settled around the "O" in "NORMAL." I've since installed a mechanical gauge, and I haven't seen it more than 160 degrees yet- even after a 45 minute drive in 70 degree weather. I read somewhere that these motors are prone to overheating, (not saying it's fact, just something I read), and I'm wondering if a PO didn't install a low temp thermostat to prevent that. Pretending that the mechanical gauge is "wrong," is there an easy way to determine what temp the thermostat is opening at without just replacing it? And if I do replace it, (living in Michigan), what temp should I replace it with? A 205, 195, 190, 180- assuming it has a 160 in it now? I just want it to run a little warmer, but I also don't want to shoot myself in the exhaust by going too high and end up regretting it. What temp do you all run?

 

the 300 isn't more prone to overheating than any other engine, if you take into account maintenance levels from engine to engine. I think you're probably hitting the nail on the head that the thermostat in there is too cold. Swap it over for a 190 or 195 (195 is OEM for the EFI 300's, I don't actually know what it is for the carbureted models).

I've found that most reports of any old pickup overheating most often has more to do with some joker had to replace the radiator at some point, *or* had the fan hit the shroud, or something, and instead of actually doing it right, old cleetus would just pitch the fan shroud, because it was too much trouble to deal with. Yeah, they can be a pain in the **** to work around, but they *do* make a *huge* difference as to whether an engine stays cool or not.

 

Mine's an '84 that had "some emission controls" and "some sort of ECM" that were all deleted before I got it. However, it's funny you should mention the radiator and shroud... I'm not sure my setup is "stock" and the shroud clearly doesn't seem deep enough. This is a picture of my shroud, and you can see where I painted the corners of the fan white because you don't want to bump into it twice =( . Also, the shroud says, "COOLING SYSTEM NOT EQUIPPED FOR A/C" which is weird because I actually removed the A/C compressor, brackets and remaining vacuum goodies attached to it. The sliders in the cab did not indicate nor have controls for A/C, but there was definitely a compressor... which is why I'm questioning cooling.

 

If only my 81 F100 Flare side factory gauge would read that high, mine sits at the first line.
I have replaced the stat twice, both 195 and I thought I may not have changed it or was stuck open, not true on both.
I also changed the sending unit 2 times. First the gauge did not work, second because it was reading low.

If I sit at idle for a long time (10 min or more) with AC on, OAT 90* to 95*, it will go up to half gauge, where I think it should run all the time, then drop done to the first line once moving.

On the 80's Fxxx trucks at least on the 300 six the only time it got a fan shroud was with factory AC.
Now being you had the AC compressor it could be 1 of 2 things>
The motor was a used motor and that car / truck had AC and it was not removed (not likely)
Or you had dealer installed AC.

Your "shroud" is to protect fingers from the fan and that's it. Here is a factory shroud.


I have a car that never came with a shroud and was having over heating issues. I found a shoud that fit with a little work and it did bring the temp down but the motor is full of mudd and it keeps the heat from being pulled out of the head & block. Everything else it new and still would over heat. It had 4 rusted freeze plugs that are rubber and 1 of them is in a head! When have you ever seen a freeze plug in a head rust out?
Dave ----

 

I actually have! Once. It was in an old 223 Straight Six in like a late fifties Ford Pickup, as I recall.

But that's the only one that I've personally experienced.

 

These trucks have enough radiator that they will run fine without a shroud if the clutch is somewhat working and the radiator isn't too plugged.

I'd still run one because the extra cooling power is gonna buy time if/when you spring a leak.

As others have stated, only the trucks with A/C have a "real" shroud.

 

I also want to say only the AC trucks (80-86) used a clutch fan.
FYI my motor came from something with out AC or the non-AC fan was swapped on to the motor as the truck (81 f100) did not have AC from the factory.
I have since added factory AC, yes swapped half the firewall, but I did not have the clutch fan so I am using the direct drive fan & shroud and have no issues with over heating.
Dave ----