Started By
Message

Heater in truck only warms air when accelerating?

Posted on 11/1/22 at 12:58 pm
Posted by LSUSoulja08
Member since Oct 2007
16969 posts
Posted on 11/1/22 at 12:58 pm
2013 F150 lariat. Haven’t needed the heat in months but with some cooler mornings I’ve needed the defrost for foggy windows.

Air coming from vents is cold until I put my foot in it and then it warms pretty immediately.

Any thoughts? Googling hasn’t resulted anything helpful yet
Posted by deeprig9
Unincorporated Ozora
Member since Sep 2012
73183 posts
Posted on 11/1/22 at 1:00 pm to
Check that your radiator fluid is topped off.
Posted by LSUSoulja08
Member since Oct 2007
16969 posts
Posted on 11/1/22 at 1:02 pm to
Hmm hadn’t checked that, will do
Posted by deeprig9
Unincorporated Ozora
Member since Sep 2012
73183 posts
Posted on 11/1/22 at 1:06 pm to
The second thing I would suspect is the water pump impeller is fricked up. Works ok under RPM but worthless at idle. But I'm not a ford guy so I wouldn't know the best way to check for that.
Posted by LSUSoulja08
Member since Oct 2007
16969 posts
Posted on 11/1/22 at 1:08 pm to
I appreciate the thoughts! I’m wanting to investigate myself before thinking about mechanic taking a look
Posted by keakar
Member since Jan 2017
30152 posts
Posted on 11/1/22 at 1:24 pm to
quote:

I appreciate the thoughts! I’m wanting to investigate myself before thinking about mechanic taking a look


also keep in mind most dash vents have doors that operate to adjust how hot and cold it is. one of those actuators could be the issue.

youtube is full of useful info and how to fix things like this, try a trip down the youtube rabbit hole and see if its a common problem for your truck
Posted by LSUSoulja08
Member since Oct 2007
16969 posts
Posted on 11/1/22 at 1:41 pm to
It seems like such an odd problem but it’s one that isn’t a major issue, more just inconvenience, so I think I’ll do that.

Mainly curious if anyone else has experienced it as well
Posted by Soul Gleaux
Baton Rouge
Member since Sep 2012
4212 posts
Posted on 11/1/22 at 2:03 pm to
If you haven’t already fixed leaks in your coolant lines by now, check for signs of leakage if your coolant is in fact low. Mine at one time was leaking from the Y junction in front of the throttle body, and another time at the overflow tank. The leaks at the Y junction are easy and cheap, you can get a pack of Dorman o-rings that are within the plastic ends of the hoses. The hose that goes to the overflow tank, I found a kit that swaps it over to the traditional hose and clamp that gets tightened by a screw driver.

ETA: mine is the 5.0 fwiw
This post was edited on 11/1/22 at 2:05 pm
Posted by NatalbanyTigerFan
On the water somewhere
Member since Oct 2007
8509 posts
Posted on 11/1/22 at 2:55 pm to
Your heater core might need to be flushed.

Just google your year model and heater core flush, there's probably a video on YouTube how to do it.
Posted by Tridentds
Sugar Land
Member since Aug 2011
23478 posts
Posted on 11/1/22 at 3:50 pm to
quote:

Your heater core might need to be flushed.


^^^^^^^^^^^^^^^^^^^^^^
Posted by thejudge
Westlake, LA
Member since Sep 2009
15064 posts
Posted on 11/1/22 at 4:07 pm to
With a 2013 f150 I'd lend to a blend door.

I have a 2013 and two of mine went out.

Pulled the dash (not that hard in these models) and changed out all 3 while I was there.

There is a door relearn procedure on the interwebs you can try first and see if that helps. Fixed my issue for a few weeks and then they fricked up again.
Posted by cdaniel76
Ponchatoula
Member since Feb 2008
19771 posts
Posted on 11/1/22 at 5:08 pm to
Most common fix for that issue on that truck is low coolant.

What's causing the low coolant levels is the kicker. Leaky hose? Possible coolant getting into the combustion chamber?

Again, another common issue is leaking connections under the coolant reservoir and at the junction pipe right under the throttle body.

(Speaking a former 2013 5.0 F150 owner who had those same issues)
Posted by WHATASHAME
Louisiana
Member since Sep 2009
717 posts
Posted on 11/1/22 at 5:12 pm to
Thermostat could be stuck open……
Posted by X123F45
Member since Apr 2015
29506 posts
Posted on 11/1/22 at 5:37 pm to
Buy one of those funnels that attaches to your radiator, put a gallon of coolant in it and then let it run. Rev a bit and see if it pulls the coolant through.

Could be as simple as a massive air pocket.

Being a ford it likely has very little of impeller left.

Posted by tigerband6971
hammond,la
Member since Sep 2018
127 posts
Posted on 11/1/22 at 5:43 pm to
Same truck model and year here
We’ve gone through 3 blend doors for same issue
Posted by Miketheseventh
Member since Dec 2017
6786 posts
Posted on 11/1/22 at 6:37 pm to
quote:

It seems like such an odd problem but it’s one that isn’t a major issue,

I have a 2002 f150 and last year I had to replace the blend next to the heater core. It was stuck in the closed position. I didn’t have any heat before that. On a side note. I was on my way to church last year and ran into a ditch because the windshield had fogged up so bad. It can be an issue
Posted by Guntoter1
Baton Rouge
Member since Nov 2020
1580 posts
Posted on 11/1/22 at 6:52 pm to
Your engine is toast
Sorry for your loss
Posted by Higgysmalls
Ft Lauderdale
Member since Jun 2016
7677 posts
Posted on 11/1/22 at 8:45 pm to
quote:

What's causing the low coolant levels is the kicker. Leaky hose? Possible coolant getting into the combustion chamber?


If there is white smoke it is getting into chamber. The leak sealant that you add to antifreeze usually does a good job
Posted by Harlan County USA
Member since Sep 2021
733 posts
Posted on 11/1/22 at 9:51 pm to
2017 F150 5.0 117,000 miles. If losing coolant... mine was losing coolant about a year ago and turned out to be the Y pipe coolant connector that connects the upper radiator hose and the thermostat housing to the engine. The dealer parts guy said that had been a problem for awhile and Ford had redesigned the Y pipe a few times. I fixed that easily enough then had to replace the water pump this summer. The bearing inside went bad and was making that unmistakable sound. No help as far as the vents.

Def have to flush coolant out and refill every few years. I've done that already for mine.
Posted by Tiger2712
Member since Nov 2018
136 posts
Posted on 11/1/22 at 10:06 pm to
Check vacuum lines
first pageprev pagePage 1 of 2Next pagelast page

Back to top
logoFollow TigerDroppings for LSU Football News
Follow us on X, Facebook and Instagram to get the latest updates on LSU Football and Recruiting.

FacebookXInstagram