Question about 2001 GMC Sonoma Extended Cab

2 Answers

Truck heating system changes from heat, defrost, and vent

I have a 2001 GMC Sonoma 4x4 with a 4.3L engine. When the truck is under load the heating system will change from heat,defrost, and vent

Posted by on

Ad

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,985 Answers

Thats normal, you are taking vacume from the heater system when you are under a load,but it returns when you let back up on pedal,if you wanted to alter this affect you might try installing a vacume ball to the heater vacume hose,

Posted on Jan 02, 2010

Ad
  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • GMC Master
  • 740 Answers

You have a vaccum leak. first place to check believe it or not is under the hood a small vaccum leak when under load will do this to the heat ( i know i have the same truck and had the same problem my leak was at the back of the engine compartment)

Posted on Jan 02, 2010

Ad

1 Suggested Answer

6ya6ya

6ya staff

  • 2 Answers

SOURCE:

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

How do I remove oil pan on a 2001 gmc Sonoma pick up truck to replace gasket


1993 GMC SONOMA 2.6 CYL V6 NOT 4x4 OIL PAN ...

? 2:31
https://www.youtube.com/watch?v=1KsRTlnW7Cg
Sep 27, 2011 - Uploaded by JohnSmiths8379858
trying to reomove the oil pan to this truck has been sitting for about 6 ... 1993 GMC SONOMA 2.6 CYL V6 NOT 4x4 OIL PAN REMOVAL "HELP!

Oil Pan Gasket: How to Change Oil Pan Gasket for 2001 ...

www.2carpros.com/questions/2001-gmc-sonoma-oil-pan-gasket
Mar 18, 2011 - How to change oil pan gasket for 2001 sonoma, can i get away with just raising the engine two inches to ... 2001 GMC Sonoma • 4 cylinder 2WD Automatic • 150,000 miles ... You need to remove the engine to get the sump off.

Nov 28, 2015 | GMC Cars & Trucks

1 Answer

I have defrost and vent function,but no heat to the floor.


sounds like your control for this function is bad also check the electronic bypass door switch electrical connection for looseness & possibly broken arms. With control on hot,the fan on low,turn the key on for @ 20 sec. With the key on turn the heat control all the way to cold now turn the key off instantly & put your ear to the floor next 2 the heat vent & u should hear the door of the vent make a whining noise hense changing from open 2 close 4 another 20 sec. GOOD LUCK!! BEEN THERE & DONE THAT!!!!

Jan 05, 2010 | 1999 GMC Sonoma

2 Answers

98 Jimmy throws out heat but won't switch to all vent options


Your going to have to replace the switch. The switch it self may have gone bad, since it works on a vacuum. It's common for the diaphragm in the switch assembly to go bad, if it's not the switch. Then it's going to be a bad actuator door and will need to be freed up. I have found it to be the switch it self get dirty and the vacuum needed to activate the actuator door is not there.

Good luck and keep me posted. When you turn the switch from defrost to heater, do you hear a air leak??? If you do then it's a good chance that it's the switch it self.

Dec 03, 2009 | 1998 GMC Jimmy

2 Answers

GMC Sonoma SLE 4.3L 1991- Coolant Temp Gauge Not reading


there are 2 coolant sensors one for gauge and one for ecm

Jul 23, 2009 | 1991 GMC Sonoma

1 Answer

Engine Swap


you will need a new bell housing and i would change the radiator

Apr 13, 2009 | 2001 GMC Sonoma Extended Cab

1 Answer

Heat not working right


close the firewall damper under the dash

Mar 22, 2009 | 2001 GMC Jimmy

4 Answers

The heater still won't work after I changed the thermostat on my


Get a female garden hose adapter from the local hardware store. Disconnect the heater hose from behind the fan pulley and attach the hose connection. Disconnect the other heater hose behind the alternator, aim it towards the ground and flush water through the heater core. This worked on my truck.

Feb 12, 2009 | 1999 GMC Sonoma

2 Answers

Window defrost


it all has to do with vacums basically, when you turn the switch to defrost there is a hose that should **** a "door" so to speak over lettin the air travel through your defrost vents, and if your not gettin suction the in aint gonna switch over, and are you gettin it out of the floor vents?

Dec 22, 2008 | 1997 GMC Sierra

Not finding what you are looking for?
2001 GMC Sonoma Extended Cab Logo

Related Topics:

304 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

Marvin
Marvin

Level 3 Expert

85222 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...