Heater won't stay hot?

Tiny
MMCK1313
  • MEMBER
  • 2002 CHEVROLET S-10
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 78,000 MILES
I have a 2002 chevy s-10 zr-2. I have a problem with my heater that is driving me crazy. I have changed the thermostat and flushed my cooling system. When I first start it, it seems the heater is working fine. The air is very hot. After it comes up to running temp, the heat slowly turns cold. The selector for my vents is not working correctly. It will not switch between face and feet etc. The water going in is hot, the return is cold. Has anyone heard this problem before? I am at my end and need help.
Sunday, December 16th, 2007 AT 4:02 PM

2 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
The water going in is hot, the return is cold.

Look for a heater control valve-check for clogging heater hose/s and heater core.
Was this
answer
helpful?
Yes
No
Sunday, December 16th, 2007 AT 4:20 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
It sounds like you have two problems, the first is the heater core is clogged I would use a garden hose to help flush it out, next I would make sure the vacuum source under the hood that goes to the fire way and the HVAC system is not broken. Please go over this video it will help;

https://www.youtube.com/watch?v=SNRb6pSwYuU&t

Please go over this guide as well for the broken vacuum line.

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position

Please go over these guides and get back to us.
Was this
answer
helpful?
Yes
No
Friday, November 22nd, 2024 AT 3:20 PM

Please login or register to post a reply.

Sponsored links