2000 GMC SONOMA 4.3

  • Tiny
  • skipel23
  • 2000 GMC Sonoma
  • 6 CYL
  • 2WD
  • automatic
  • 75,000 miles

Enter your question.I DON'T HAVE ANY HEAT, I replaced the therm. And all. Switches seem to be working. There dosen't seem to be any water circulating thru heater core. The engin isn't overheating. Could this still be the water pump.

Friday, November 19th, 2010 AT 10:32 PM

12 Answers

  • Tiny
  • BMRFIXIT
  • Expert
  • 19,554 posts

Does it run at operating temp?
Run engine and check heater hoses by the fire wall if both hot and no hot air inside
problem is in the heater box and blend door or blend door actuator

Was this
answer
helpful?
Yes
No
Friday, November 19th, 2010 AT 11:04 PM
  • Tiny
  • rasmataz
  • Member

Also check if it has a heater control valve

Was this
answer
helpful?
Yes
No
Friday, November 19th, 2010 AT 11:11 PM
  • Tiny
  • skipel23
  • Member

The engin runs at operating temp. The inlet hose gets warm, but not hot and the exit hose stays cool. It is like there isn't enought pressure in the line. Does the blend box stop the flow of the water.

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 7:33 PM
  • Tiny
  • BMRFIXIT
  • Expert
  • 19,554 posts

They do not use a valve in this system and blend system was used
as they direct the air thro and over the heater core and or the AC system and fresh air

heater core need to be isolated and flushed

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 7:48 PM
  • Tiny
  • skipel23
  • Member

I did that and water runs thru it freely.

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 7:59 PM
  • Tiny
  • BMRFIXIT
  • Expert
  • 19,554 posts

If water running thru freely and no heat on the inside, engine reaching operating temp,
check blend door operation and I would suspect the actuator on the door

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 8:03 PM
  • Tiny
  • skipel23
  • Member

When I say water is rinning freely, It is with the hoses disconnected. How do I get to the actuator.

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 8:11 PM
  • Tiny
  • BMRFIXIT
  • Expert
  • 19,554 posts

Under the dash on the heater box
i will try to find a picture for you

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 8:13 PM
  • Tiny
  • skipel23
  • Member

Thanks

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 8:16 PM
  • Tiny
  • BMRFIXIT
  • Expert
  • 19,554 posts

This a picture of the part and what it look like
let me know

Was this
answer
helpful?
Yes
No
Saturday, November 20th, 2010 AT 8:17 PM

Please login or register to post a reply.

Similar Questions