Heater blew nothing but cold air that evening

Tiny
MIKIE
  • MEMBER
  • FORD F-150
I replaced the stat in my '97 Ford F150 - 4.6L. The heater worked perfectly the next morning. It blew nothing but cold air that evening and always since. Other than possibly having the wrong stat or a defective one is there any other reason I would have this problem not withstanding a clogged heater core (which it's not). By the way I tried to donate to your cause but the link didn't work (some kind of error).
Monday, February 5th, 2007 AT 7:05 PM

1 Reply

Tiny
MIKE H R
  • MECHANIC
  • 3,094 POSTS
Try starting the engine when its cold. Holding the hose closest to the thermastat. The hose will stay cold until the thermastat opens. You should feel a sudden temperature change. Means the thermastat working properly. If the temp rises slowely than may be a stuck open thermastat. Have seen new ones that were bad. If the thermaste works ok then the heater core might be vapor locked or clogged.
Was this
answer
helpful?
Yes
No
Monday, May 10th, 2021 AT 10:36 AM

Please login or register to post a reply.

Sponsored links