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

1,305

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 34 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

  • 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

  • Oil pump or something else please help urgent 18 answers

    I have a 2007 gmc 2500 hd with 6.0 gas engine.oil pressure gage dropped to nothing and alarm went off saying low oil pressure shut off engine.oil is clean and up to par.no leaks or knocking pingin...

    2007 GMC Sierra 2500HD 4 Dr Work Truck Crew Cab 4WD

    -

    Maintenance & Repair

Search GMC Sierra 1500 Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 4,620
#2 John Saffrahn
John Saffrahn
Reputation 3,230
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 2,890
View All

Related Models For Sale

Used Chevrolet Silverado 1500
2,589 Great Deals out of 151,216 listings starting at $1,500
Used Ford F-150
2,996 Great Deals out of 207,380 listings starting at $1,200
Used GMC Sierra 2500HD
149 Great Deals out of 13,196 listings starting at $3,500
Used Toyota Tundra
662 Great Deals out of 28,046 listings starting at $2,798
Used Dodge Ram 1500
506 Great Deals out of 12,874 listings starting at $1,800
Used Chevrolet Silverado 2500HD
378 Great Deals out of 27,109 listings starting at $2,998
Used Toyota Tacoma
696 Great Deals out of 31,772 listings starting at $2,750
Used GMC Yukon
543 Great Deals out of 16,892 listings starting at $2,495
Used Chevrolet Tahoe
872 Great Deals out of 27,786 listings starting at $1,700
Used Ford F-250 Super Duty
436 Great Deals out of 42,932 listings starting at $2,195
Used GMC Sierra 1500HD
4 Great Deals out of 113 listings starting at $4,500
Used GMC Canyon
130 Great Deals out of 7,995 listings starting at $2,200

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
22 Great Deals out of 32,620 listings starting at $23,800
2016 GMC Sierra 1500 For Sale
71 Great Deals out of 4,699 listings starting at $18,710
2015 GMC Sierra 1500 For Sale
138 Great Deals out of 4,262 listings starting at $15,888
2014 GMC Sierra 1500 For Sale
166 Great Deals out of 4,299 listings starting at $13,800
2013 GMC Sierra 1500 For Sale
116 Great Deals out of 2,459 listings starting at $9,500