Question - FordTough.ca - Home of Canadian Ford Truck Enthusiasts
Reply
 
LinkBack Thread Tools Search this Thread Rate Thread Display Modes
post #1 of 12 (permalink) Old 01-15-2013, 08:24 PM Thread Starter
Apprentice
 
Join Date: Jan 2013
Location: Vancouver
Posts: 6
Question

Hello Everyone,

I have a question that I am hoping someone can help me with. I have a 1979 Ford F250 with a 460 J-Type engine.

Recently the heater has become intermittent. I removed the old thermostat and replaced it with a new one. I checked the old one (180 degree) and it was still good but replaced it with a new one (190 degree) anyway.

The new thermostat did not correct the problem. I thought it might be the heater core, but nobody seems to think that a heater core can be intermittent.

The truck warms up nicely, no overtemp issues, the coolant level is good. To compond the confusion, In the morning I start the truck and after about 10 minutes, it blows warm air. As soon as I put it in drive, nothing but cold. If I put it in park, it may blow warm, it may blow cold.

My brain has me thinking it could be a vacuum issue. I am going to change the heater core regardless but thought you guys might have some good ideas for me.

thanks
BlueDevil is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 01-15-2013, 08:35 PM
 
I like Fords Too's Avatar
 
Join Date: Nov 2012
Location: Scarborough Ontario
Posts: 676
does your truck also have air conditioning ?

if so perhaps there is an issue with the water valve on the heater hoses that turns off the hot water flow when useing the a/c

or maybe your getting an air bubble that stops the flow of heat when it forms ?

I think my 76 water valve was cable controled (maybe) but if your's has a vacume diafram on it maybe the vac hose got routed wrong somehow
I like Fords Too is offline  
post #3 of 12 (permalink) Old 01-15-2013, 08:40 PM Thread Starter
Apprentice
 
Join Date: Jan 2013
Location: Vancouver
Posts: 6
No it does not have air conditioning. Can you purge a line to check for air bubbles? I am not exactly sure how they would form, because there are no leaks that I can see.
BlueDevil is offline  
 
post #4 of 12 (permalink) Old 01-15-2013, 10:13 PM
 
taisa899's Avatar
 
Join Date: Feb 2007
Location: Amherstburg, Ontario
Posts: 4,934
Send a message via MSN to taisa899
happened to me on a Ford Ranchero I had. Let the engine warm up and hit the throttle under the hood, see if your upper rad hose is collapsing under throttle



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!

Nitrous is like a beautiful girl with an STD. You know you want to hit it but you're afraid of the consequences
taisa899 is offline  
post #5 of 12 (permalink) Old 01-16-2013, 10:03 AM
 
Manford's Avatar
 
Join Date: Dec 2012
Location: Calgary
Posts: 109
I would bleed the heater core to start out with and just make sure you are not getting an air lock in the heater core. It can happen when the revs change the fluid flow velocity in the lines. Simple to do, take the lower hose off or even better yet get the bleeder kit from one of the parts stores, and run the vehicle till you get good flow through the core. Replace into the rad what ever you drained out while running and see if that fixes your issue.

__________

ManFord

Last edited by Manford; 01-16-2013 at 12:55 PM.
Manford is offline  
post #6 of 12 (permalink) Old 01-16-2013, 12:33 PM
 
I like Fords Too's Avatar
 
Join Date: Nov 2012
Location: Scarborough Ontario
Posts: 676
knowing these trucks didn't come with coolant recovery bottles for the rad to spit into , maybe it's sucked enough air back into the system to trap a bubble in it somewhere

when my 79 goes back together I intend to add a recovery bottle / can to mine - maybe it's a good idea to think about adding one to your's too

might be an idea to try hooking the garden hose up to each tube of the core , one side at a time to see if you can flush any crud out of the core that may be blocking the small tubes inside it - if there is a large chunk of scale floating loose in the tank on the hearter core it could be blocking it off internally - though I'd still bet my dollar on an air bubble first
I like Fords Too is offline  
post #7 of 12 (permalink) Old 01-16-2013, 01:11 PM Thread Starter
Apprentice
 
Join Date: Jan 2013
Location: Vancouver
Posts: 6
thanks for the suggestions guys. I will give them a shot before changing out the heater core altogether and report back.
BlueDevil is offline  
post #8 of 12 (permalink) Old 01-16-2013, 02:14 PM
 
Manford's Avatar
 
Join Date: Dec 2012
Location: Calgary
Posts: 109
Quote:
Originally Posted by BlueDevil View Post
thanks for the suggestions guys. I will give them a shot before changing out the heater core altogether and report back.
yep, for sure, you would have to do this anyway if you install a new hearter core.

__________

ManFord
Manford is offline  
post #9 of 12 (permalink) Old 01-16-2013, 06:13 PM
 
Destructicon's Avatar
 
Join Date: Mar 2010
Location: Stoney Creek, Ontario
Posts: 1,507
Garage
How large is the radiator? How many blades on the fan? Is it a clutch fan?

Electrician, powered by Tim Hortons, brought to you by Ford. Java Inside!
The Past - 1976 F-350 Crew Cab 1992 - 2006 RIP
The Past - 1995 F-150 XL Enforcer All Gear Drive 2008 - 2015
The Present - 1993 F-250 XLT Turbo Diesel Super Cab 4x4 2015 - ?
The Future - Who knows?
Destructicon is offline  
post #10 of 12 (permalink) Old 01-31-2013, 09:44 PM Thread Starter
Apprentice
 
Join Date: Jan 2013
Location: Vancouver
Posts: 6
update - I did pretty much everything you could possible do to correct this problem and nothing worked. I was in a parking lot and had the hood up looking and trying to see what I was missing when this old timer came over to admire the truck. He asked what the problem was and after telling him, he takes one look and says, "one of your hoses is too long" and it hit me like a ton of bricks, the longer hose created a 'p - trap'...problem solved.
BlueDevil is offline  
Reply

Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Similar Threads
Thread Thread Starter Forum Replies Last Post
Question Denis254 Audio and Electronics 1 04-11-2009 01:33 AM
Question Denis254 Ranger Forum 8 12-08-2008 12:37 AM
NEED HELP: Question Denis254 Ranger Forum 5 11-16-2008 12:26 AM

Posting Rules  
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome