I have A 08 GMC Sierra 6.0 1500. My heat only works when I am driving the truck. It blows cold air when the truck is in park no matter how long it idles. Any ideas on what could be the issue?

Asked by Nov 24, 2015 at 06:36 AM about the 2008 GMC Sierra 1500 SLE1 Crew Cab 4WD

Question type: Maintenance & Repair

I have even driven the truck to get the heat
warm and then put it back in Park in let it
idle and it cools back off

1 Answer

1,355

i think it is your thermostat

Your Answer

Add photo

Related Questions

  • No heat any ideas? 7 answers

    Ive got a 95 gmc 1500. I recently replaced the heater core along with the hose from the core to the water pump and hose assembly to the block. I have no heat and my fan will blow light at time th...

    1995 GMC Sierra 1500

    -

    Maintenance & Repair

  • Truck won't start 42 answers

    Recently I have experienced starting issues. One minute it starts and runs great, next time I try to start it it turns over but won't start. Let sit for awhile, turn key, won't start, turn key off...

    1988 GMC Sierra 1500 C1500 Standard Cab SB

    -

    Maintenance & Repair

  • Will not move in Drive or Reverse 14 answers

    1995 GMC Sierra k1500, 350, 5.7 Automatic : Take it out of park, into drive or reverse, step on gas, rpm's fly, but won't move an inch. Have not driven in a week or so, had to replace radiator becaus...

    1995 GMC Sierra 1500 K1500 SLE 4WD Extended Cab SB

    -

    Maintenance & Repair

  • Heater in my 1992 GMC Sierra doesn't blow hot air. 3 answers

    The heater core is hot, and the doors all work but it will only blow out cold air. What is the problem? Thanks.

    1992 GMC Sierra 1500 C1500 SLE Extended Cab LB

    -

    Maintenance & Repair

  • GMC 208 sierra truck the engine hot sensor is on and the air conditioner won't come on 3 answers

    GMC 208 sierra truck the engine hot sensor is on and the air conditioner won't come on

    GMC Sierra 1500

    -

    Maintenance & Repair

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 5,010
#2 John Saffrahn
John Saffrahn
Reputation 3,530
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 3,140
View All

Related Models For Sale

Used Chevrolet Silverado 1500
1,658 Great Deals out of 174,454 listings starting at $1,300
Used Ford F-150
2,211 Great Deals out of 205,382 listings starting at $1,499
Used GMC Sierra 2500HD
116 Great Deals out of 13,953 listings starting at $2,650
Used Toyota Tundra
438 Great Deals out of 34,121 listings starting at $3,200
Used Dodge Ram 1500
471 Great Deals out of 11,174 listings starting at $700
Used Toyota Tacoma
523 Great Deals out of 40,494 listings starting at $2,495
Used GMC Yukon
347 Great Deals out of 17,898 listings starting at $2,950
Used Chevrolet Silverado 2500HD
316 Great Deals out of 27,536 listings starting at $1,250
Used Chevrolet Tahoe
559 Great Deals out of 28,789 listings starting at $1,699
Used Ford F-250 Super Duty
335 Great Deals out of 46,816 listings starting at $1,895
Used GMC Canyon
93 Great Deals out of 9,136 listings starting at $2,495
Used Chevrolet Colorado
218 Great Deals out of 24,165 listings starting at $2,495
Used GMC Sierra 1500HD
7 Great Deals out of 113 listings starting at $2,995

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
39 Great Deals out of 43,569 listings starting at $20,121
2016 GMC Sierra 1500 For Sale
81 Great Deals out of 3,701 listings starting at $17,888
2015 GMC Sierra 1500 For Sale
96 Great Deals out of 3,935 listings starting at $15,400
2014 GMC Sierra 1500 For Sale
100 Great Deals out of 4,182 listings starting at $14,495
2013 GMC Sierra 1500 For Sale
72 Great Deals out of 2,023 listings starting at $9,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.