bNasty

Alright guys as the title says I need some help. Ive been having problems with the truck running hot. Its not overheating but the truck is running warm. It will usually stay around the A or the L in NORMAL. So i basically replaced everything in the cooling system. I put in a new thermostat, new 4 core radiator, new water pump. and even a new sensor for the gauge in the dash. And its still running in about the same place.

I know its not the Head gasket. There are no bubbles in the coolant and theres no milky crap in the oil.

Before on cooler days it would run around the M or the A in NORMAL but then randomly one day it creeped up then when back down in the middle right between the R and the M. So i replaced the T-stat and it ran hotter toward the A and the L.

Do you guys think that switching to a cooler 180 t stat would help my problem? Vehicle is an 86 302 FI

mustangGT90210

Invest in a mechanical water temp gauge so you can see the real temperature of everything. It's possible the stock gauge in the truck just likes to rest there for normal temp. I know in my '91 it'll be at normal operating temp and barely register on the gauge, and it'll overheat when the gauge reaches the M in NORMAL.

bNasty

Yea thats the plan for tomorrow. Hopefully I can figure this out. I need an actual temperature instead of M in NORMAL.

19905.0-123

If it still runs hot with your new gauge I'd put a cooler thermostat on it chances are the new accurate gauge will say that she's running just fine

Seattle F-150

HGello, I have the SAME issue? Was there a solution to this yet? I thought it may be the guage and the temp was just fine however I am wondering if you found out what it was.
I just bought a 1986 F-150 4x4, just drove it hoke tonight. I am gpoing to change the auto to manual trans, and I believe that will cost me...

thanks

klricks

Is that at idle or driving?
Mine fluctuates from O to M at idle. However I wouldn't have been concerned unless the needle pegs to H or stays at C. I assume normal is anything between N and L.
C [NORMAL] H

You did not mention the fan clutch. Not sure how to tell if the clutch is working properly? But if not the fan may not be up to speed.

bNasty

Well i dont have a fan clutch in this truck. I figured out the problem it turned out to be a faulty gauge i picked up a cheap gauge from advanced and i see temps around 190-200

klricks

So was your OEM fan clutch replaced at some point by a fixed fan?
Almost all cars/trucks have a fan clutch of some sort. When engine is cold with engine off the fan should freely spin.
I think my clutch is bad because my AC does not cool well but gets much colder when I spray water on the condenser.

bNasty

honestly i have no idea. When I bought the truck it was like that. It doesnt look like its been replaced. All looks oem and all parts look old.

klricks

Here is what the fan clutch looks like:
http://www.autozone.com/autozone/par...mString=search

It's purpose is to regulate the speed of the fan depending on the engine temperature.

If the clutch is frozen then the fan will always spin at full speed which will make the engine take a long time to warm up and rob gas mileage.

If the fan clutch is not engaging the fan when it should then of course you get various levels of overheating.

Here is a writeup on fan clutches, how they work and how to test:
http://www.mwrench.com/Whitepapers/FanClutchtest.pdf