Overheating
Thread Starter
|
Senior User
Joined: Feb 2009
Posts: 116
Likes: 0
Overheating
I've got a 86' F-350 6.9. I've been having trouble with it overheating I have replaced the radiator,thermostat,and fan clutch,the water pump is a year old,it does fine just driving around town but when I get out on the highway it get's hot if I pull over it cool's down(fast like less than 2 min.)I used to never have this prob,I used to drive down the highway with my plow all the way up and would not even get warm,I used to have trouble keeping the cab warm...any help would be great thanks!
Lead Driver
Joined: Dec 2006
Posts: 6,496
Likes: 94
From: So. Jersey
Do you have good flow through the rad?
Did you replace the thermostat with genuine International or Ford Motorcraft unit? Many claim early failure using after market thermostats.
Are you natural or turbo?
Did you replace the thermostat with genuine International or Ford Motorcraft unit? Many claim early failure using after market thermostats.
Are you natural or turbo?
Thread Starter
|
Senior User
Joined: Feb 2009
Posts: 116
Likes: 0
it was a NAPA thermostat,but I'm thinking of a international one,Natural
Lead Driver
Joined: Dec 2006
Posts: 6,496
Likes: 94
From: So. Jersey
Id start with the thermostat. May be sticking or only partially opening. Check to see if you see any bubbles in your coolant resevoir/radiator when it's running, as this could be a sign of blown or weak headgasket.
Thread Starter
|
Senior User
Joined: Feb 2009
Posts: 116
Likes: 0
I've checked for bubble's..none so far
Lead Driver
Joined: Dec 2006
Posts: 6,496
Likes: 94
From: So. Jersey
That's a good thing. When you do that thermostat don't forget there is a little check ball that has to be reinstalled, make sure it's not clogged or stuck.
Thread Starter
|
Senior User
Joined: Feb 2009
Posts: 116
Likes: 0
where is it at?
Trending Topics
Senior User
Joined: Nov 2009
Posts: 283
Likes: 0
No idea if you have the same layout as us on our 85, 6.9 but we just went through this kind of thing although it didn't trigger the fan or the light.
We took everything apart and cleaned the mating surfaces of the thermostat neck, and the beebee ball and its cavity and it was caked with red rtv! There is no way it was acting as it should and luckily for us the retainer for the ball was intact.
Also for peace of mind we started fresh, at the advice of people here, and got a genuine ford motocraft thermostat.
Well yesterday was the day we got it all back together and its all acting normally! From idle warmup to driving it around on the freeway, etc.
Now I can burp it easier and everything flows very nicely
We are new to diesels and didn't know any better, assumed it just wasn't getting up to temperature. I would have hate to have this happen during the summer when we towed, but thank goodness for this awesome site and the search function
Here are some pictures of my story, have no idea what the previous owner was doing
We took everything apart and cleaned the mating surfaces of the thermostat neck, and the beebee ball and its cavity and it was caked with red rtv! There is no way it was acting as it should and luckily for us the retainer for the ball was intact.
Also for peace of mind we started fresh, at the advice of people here, and got a genuine ford motocraft thermostat.
Well yesterday was the day we got it all back together and its all acting normally! From idle warmup to driving it around on the freeway, etc.
Now I can burp it easier and everything flows very nicely
We are new to diesels and didn't know any better, assumed it just wasn't getting up to temperature. I would have hate to have this happen during the summer when we towed, but thank goodness for this awesome site and the search function Here are some pictures of my story, have no idea what the previous owner was doing
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Truck Tragedies
Joe Kucinski
Cargo Master
Joined: Oct 2008
Posts: 3,330
Likes: 13
From: Eaton, CO
No idea if you have the same layout as us on our 85, 6.9 but we just went through this kind of thing although it didn't trigger the fan or the light.
We took everything apart and cleaned the mating surfaces of the thermostat neck, and the beebee ball and its cavity and it was caked with red rtv! There is no way it was acting as it should and luckily for us the retainer for the ball was intact.
Also for peace of mind we started fresh, at the advice of people here, and got a genuine ford motocraft thermostat.
Well yesterday was the day we got it all back together and its all acting normally! From idle warmup to driving it around on the freeway, etc.
Now I can burp it easier and everything flows very nicely We are new to diesels and didn't know any better, assumed it just wasn't getting up to temperature. I would have hate to have this happen during the summer when we towed, but thank goodness for this awesome site and the search function
Here are some pictures of my story, have no idea what the previous owner was doing
We took everything apart and cleaned the mating surfaces of the thermostat neck, and the beebee ball and its cavity and it was caked with red rtv! There is no way it was acting as it should and luckily for us the retainer for the ball was intact.
Also for peace of mind we started fresh, at the advice of people here, and got a genuine ford motocraft thermostat.
Well yesterday was the day we got it all back together and its all acting normally! From idle warmup to driving it around on the freeway, etc.
Now I can burp it easier and everything flows very nicely
We are new to diesels and didn't know any better, assumed it just wasn't getting up to temperature. I would have hate to have this happen during the summer when we towed, but thank goodness for this awesome site and the search function Here are some pictures of my story, have no idea what the previous owner was doing
Senior User
Joined: Dec 2009
Posts: 180
Likes: 0
Hey fellas,
I'm replacing the thermostat soon (with a motocraft one)...... my truck is an 86 F250.
The check ball that needs to be cleaned up (hopefully mine's not bad like the pictures above!) Does it come out of the housing? If so, how? I figure that would make it a lot easier to clean it up if required... Thanks in advance
I'm replacing the thermostat soon (with a motocraft one)...... my truck is an 86 F250.
The check ball that needs to be cleaned up (hopefully mine's not bad like the pictures above!) Does it come out of the housing? If so, how? I figure that would make it a lot easier to clean it up if required... Thanks in advance
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
The check ball should be staked into the housing.
But after all these years many of them will come out.
Going back to the original post, when the temp is increasing do you ever hear the fan clutch lock up?
But after all these years many of them will come out.
Going back to the original post, when the temp is increasing do you ever hear the fan clutch lock up?
Thread Starter
|
Senior User
Joined: Feb 2009
Posts: 116
Likes: 0
It's hard for me to hear the fan becuase of my exhaust,but it seem's to come on,although not all the time or at the right time's,as for the check ball what is it for?
Posting Guru
Joined: Aug 2006
Posts: 1,049
Likes: 0
From: Perry Georgia
The check valve lets the air out of the coolant system so you don't get an air block. I had to fix my ball check valve holder because the ball would come out if I left it as it was. I used a brass compression fitting nut that was slightly bigger in diameter than the hole and filed it flat with the housing. When you have fixed it you will be able to hear the ball rolling around inside the coolant neck that the upper coolant hose is held onto.