77 F100 351m overheating problem
Thread Starter
|
New User
Joined: Nov 2003
Posts: 1
Likes: 0
From: Seattle
77 F100 351m overheating problem
77 F100 351 M is running too hot. I recently replaced the radiator, water pump, thermostat, and heat sensor. I put in a 180 degree thermostat when the OEM calls for a 192 degree thermostat in an effort to run the truck at a cooler temp. When I run the truck the temp gauge reads higher than I think is normal. as you know on the temp gauge you have the letters "TEMP" and the needle runs consistently in between the "M" and the "P" in the Temp gauge. I think that it is running too hot. should I go back an put the 192 degree Thermostat in the truck? does anyone have any suggestions?
Posting Guru
Joined: Oct 2003
Posts: 1,309
Likes: 0
From: northern ca
is the truck running too hot, or is the temp guage just reading high ?
reading around here, it seems like the guages aren't the most definitave things in the world
do you have any power loss or deiseling when the truck is hot?
reading around here, it seems like the guages aren't the most definitave things in the world
do you have any power loss or deiseling when the truck is hot?
Trending Topics
Junior User
Joined: Sep 2003
Posts: 66
Likes: 0
351m's generally do run hot.. however if the guage is consistent i wouldn't worry about it.. i would only worry if the guage was reading hotter or colder then it normally does.. i've heard that the number 8 cylinder on 351m's runs hotter then the rest of the engine and wears out faster..anybody know if thats true? on another note.. have u tried a 4-core rad?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Elder User
Joined: Jul 2003
Posts: 504
Likes: 0
From: west central florida
I would check for proper temp too, first......in addition, the cleveland/modified engines require a special t-stat that is no longer available, to upgrade a stock one ( 180* is fine), drill a tiny hole, 1/16" to 3/32" in the new t-stat housing to allow air to escape, these systems were hard to bleed and this will allow it to bleed itself good luck 
Elder User
Joined: Jul 2003
Posts: 504
Likes: 0
From: west central florida
thanks for the update on the t-stat availability eric......i upgraded to a 460 many moons ago and haven't needed to look for them recently, but i do know other that still run the 351/400 ( that is why i know about the hole drilling solution) 
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
I almost always drill a small hole or remove the "jiggle pin" in the stat to allow a small amount of water to circulate past the stat. I think they regulate and open/close better that way. I bought my last RS stats at Auto Zone but I had heard they were loosing that line. Worth a check tho.
I'll have the Roast Duck
Joined: Jul 2002
Posts: 9,622
Likes: 110
From: Northshore, MN
do ya have cold air coming out the vents in the cab when it should be hot air? Perhaps yer heater core is rusted out. I had mice build a nest in mine and it clogged it up and rusted it out. One other note, my temp gauge always says normal inside a half circle shaped box. not TEMP....was this an option?