300 cooling problems
Thread Starter
|
New User
Joined: Aug 2015
Posts: 19
Likes: 0
300 cooling problems
Having an issue with my truck with a 300 strait 6. I didn't run truck for a month while I rebuilt front end. As soon as I got it back on the road it started overheating. I replaced thermostat (195) and radiator cap but now it is VERY slow to heat up. The previous thermostat was 195 also.
Another issue is I put a new radiator in a year ago and when it overheated it started seeping out of the joint at the filler neck and top of radiator. Bad radiator? It did this with old cap and new.
Another issue is I put a new radiator in a year ago and when it overheated it started seeping out of the joint at the filler neck and top of radiator. Bad radiator? It did this with old cap and new.
Lead Gopher
Joined: Aug 2012
Posts: 10,066
Likes: 1,622
From: Seattle
If the radiator is leaking above the coolant level then it is probably letting air into the system and probably not pressurizing correctly. The pressure raises the boiling point of the coolant so if it is not pressurizing fully then it reaches boiling sooner than if it is under pressure. You could get the radiator pressure tested and possibly repaired if that is the issue, rather than replacing it.
Water boils at 212 degrees at sea level.
A proper coolant mix might boil at 223 degrees with one pound of pressure.
At 15 PSI the boiling point of the same coolant goes up to 257 degrees.
Chad
Water boils at 212 degrees at sea level.
A proper coolant mix might boil at 223 degrees with one pound of pressure.
At 15 PSI the boiling point of the same coolant goes up to 257 degrees.
Chad
New User
Joined: May 2018
Posts: 14
Likes: 0
If the radiator is leaking above the coolant level then it is probably letting air into the system and probably not pressurizing correctly. The pressure raises the boiling point of the coolant so if it is not pressurizing fully then it reaches boiling sooner than if it is under pressure. You could get the radiator pressure tested and possibly repaired if that is the issue, rather than replacing it.
Water boils at 212 degrees at sea level.
A proper coolant mix might boil at 223 degrees with one pound of pressure.
At 15 PSI the boiling point of the same coolant goes up to 257 degrees.
Chad
Water boils at 212 degrees at sea level.
A proper coolant mix might boil at 223 degrees with one pound of pressure.
At 15 PSI the boiling point of the same coolant goes up to 257 degrees.
Chad
What troubleshooting can can I do to ensure that the coolant is flowing properly to the engine?
i seem to recall that I did change out the thermostat when I changed the radiator, but I could be wrong.
Thanks.
More Turbo
Joined: Jan 2009
Posts: 547
Likes: 11
My 79 I6 is having a cooling problem as well. The top of the radiator is much warmer than the bottom half. The return hose at the bottom is cool and can be compressed in my hand. The top hose is much warmer and isn't easily compressed. It's been a while since I changed the radiator so I don't remember, but is there a hard tube inside the top radiator hose?
What troubleshooting can can I do to ensure that the coolant is flowing properly to the engine?
i seem to recall that I did change out the thermostat when I changed the radiator, but I could be wrong.
Thanks.
What troubleshooting can can I do to ensure that the coolant is flowing properly to the engine?
i seem to recall that I did change out the thermostat when I changed the radiator, but I could be wrong.
Thanks.
Dennis
Fleet Mechanic
Joined: Jul 2017
Posts: 1,448
Likes: 163
From: East Texas
Trending Topics
Cargo Master
Joined: Oct 2016
Posts: 2,738
Likes: 217
From: Northern VA
Mine had a similar issue and it required a new thermostat, coolant back-flush and lot of air bleeding / burping.
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
Thread
Thread Starter
Forum
Replies
Last Post
thedopefishlives
335 Series- 5.8/351M, 6.6/400, 351 Cleveland
6
Jul 10, 2018 02:08 PM
Wayne Waldrep
1948 - 1956 F1, F100 & Larger F-Series Trucks
61
Apr 11, 2014 06:37 PM
prginocx
1961 - 1966 F-100 & Larger F-Series Trucks
5
May 14, 2004 01:12 PM