Overheating
Junior User
Joined: Oct 2004
Posts: 92
Likes: 1
From: Rock Island, Illinois
Ahhh, a 79 with AIR CONDITIONING? You shoud give up on it immediately and just sell it to me. 
I had to try. Seriously though, I'll interject a few ideas, and I am curious about a couple things...
First the interogation: Have you checked your oil for water, or your radiator for milky foam? This could be a head gasket / warp problem. Has your TRANSMISSION been acting strangely lately? (Don't be insulted by this, but...) Did you cover your radiator last Winter to help the truck warm up faster? - did you remove the cardboard or whatever?
Ok, that aside, if the radiator has ever leaked in the past, or if the heater coil has, mabybe somebody has just packed the cooling system with bottle after bottle of stop leak, which can build in the system and block water passage.
The radiator CAP may no longer hold pressure and need replaceing.
There may be too much Antifreeze and not enough water in there, check with a hydrometer.
Hows the belt on your water pump? How is your fan shroud????
I had to try. Seriously though, I'll interject a few ideas, and I am curious about a couple things... First the interogation: Have you checked your oil for water, or your radiator for milky foam? This could be a head gasket / warp problem. Has your TRANSMISSION been acting strangely lately? (Don't be insulted by this, but...) Did you cover your radiator last Winter to help the truck warm up faster? - did you remove the cardboard or whatever?
Ok, that aside, if the radiator has ever leaked in the past, or if the heater coil has, mabybe somebody has just packed the cooling system with bottle after bottle of stop leak, which can build in the system and block water passage.
The radiator CAP may no longer hold pressure and need replaceing.
There may be too much Antifreeze and not enough water in there, check with a hydrometer.
Hows the belt on your water pump? How is your fan shroud????
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Also check that the fan belt is tight. Late ignition timing can cause overheating as well. You should also be using a fan shroud.
Trending Topics
Senior User
Joined: Dec 2005
Posts: 399
Likes: 0
Ditto the fan belt recommendation. Probably the same belt that drives your water pump, too. I couldn't hear mine slipping over the engine and tire noise but finally heard it squeal when I revved it up in my garage. Still not sure if it was slipping on the water pump or the fan but I suspect it was the water pump.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
When new, these trucks came with 192 degree thermostats...ppl complained about the gauge climbing towards hot while driving in heavy stop and go traffic, so Ford sent a letter to dealers telling them to install 180 thermostats if a customer complained.
This was done under warranty and only (AFAIK) in desert like climates in CA, AZ, NM, NV and UT.
Ford also offered 160 & 172 degree thermostats for these engines.
This was done under warranty and only (AFAIK) in desert like climates in CA, AZ, NM, NV and UT.
Ford also offered 160 & 172 degree thermostats for these engines.
Thread
Thread Starter
Forum
Replies
Last Post