2000 Tahoe 5.3 stalls at idle w/ A/C on

[ChevyPuttPutt]

My 2000 Tahoe, 5.3 Vortec, idle drops with A/C on. Sometimes it will drop to 300-400 RPM, and even go dead. Idles fine with A/C off, and otherwise runs great. Vehicle has about 85K miles. My question is this: What controls the idle step-up when A/C compressor comes on? Is it the idle motor on the side of the throttle body? Can it be adjusted, or does something need to be replaced?

[ChevyTech007]

First thing I would do is clean the throttle plate. Take the duct off the throttle body and clean it out with carb cleaner or throttle body cleaner. Common problem.

[ChevyPuttPutt]

First thing I would do is clean the throttle plate. Take the duct off the throttle body and clean it out with carb cleaner or throttle body cleaner. Common problem.

 

<{POST_SNAPBACK}>

 

 

ChevyTech,

 

Thanks for the info, I'll try that and let you know. I just thought that since it only did it when the compressor engaged, it might be something more sinister.

 

Thanks again,

 

Mike

[ChevyPuttPutt]

First thing I would do is clean the throttle plate. Take the duct off the throttle body and clean it out with carb cleaner or throttle body cleaner. Common problem.

 

<{POST_SNAPBACK}>

 

 

 

ChevyTech007,

 

Just wanted to follow up and to thank you for the good advice. Our local dealership charged me 90.00 to diagnose and told me that I needed an M.A.F Sensor and an idle motor. Parts and labor around 850.00. Hey, this would make a good MasterCard commercial:

 

Misdiagnosis, potential parts and labor - $850.00

Can of carb cleaner and some good advice from a good guy - $3.00

Being able to fix it yourself and NOT be shafted by the dealer - PRICELESS!

 

Thanks again,

 

Mike

[100R1]

First thing I would do is clean the throttle plate. Take the duct off the throttle body and clean it out with carb cleaner or throttle body cleaner. Common problem.

 

<{POST_SNAPBACK}>

 

 

 

ChevyTech007,

 

Just wanted to follow up and to thank you for the good advice. Our local dealership charged me 90.00 to diagnose and told me that I needed an M.A.F Sensor and an idle motor. Parts and labor around 850.00. Hey, this would make a good MasterCard commercial:

 

Misdiagnosis, potential parts and labor - $850.00

Can of carb cleaner and some good advice from a good guy - $3.00

Being able to fix it yourself and NOT be shafted by the dealer - PRICELESS!

 

Thanks again,

 

Mike

 

<{POST_SNAPBACK}>

 

 

 

 

 

Sounds like the dealer was trying to rip you off and not a misdiagnosis.

 

Yep, Cleaning the Throttle body on my '01 yukon fixed my low idle when the A/C was turned on. The A/C would cut in and out and not cool at such a low idle. Hard to believe how much gunk builds up on the throttle blade.

[Gonzo1970]

First thing I would do is clean the throttle plate. Take the duct off the throttle body and clean it out with carb cleaner or throttle body cleaner. Common problem.

 

<{POST_SNAPBACK}>

 

 

 

ChevyTech007,

 

Just wanted to follow up and to thank you for the good advice. Our local dealership charged me 90.00 to diagnose and told me that I needed an M.A.F Sensor and an idle motor. Parts and labor around 850.00. Hey, this would make a good MasterCard commercial:

 

Misdiagnosis, potential parts and labor - $850.00

Can of carb cleaner and some good advice from a good guy - $3.00

Being able to fix it yourself and NOT be shafted by the dealer - PRICELESS!

 

Thanks again,

 

Mike

 

<{POST_SNAPBACK}>

 

 

 

 

 

Sounds like the dealer was trying to rip you off and not a misdiagnosis.

 

Yep, Cleaning the Throttle body on my '01 yukon fixed my low idle when the A/C was turned on. The A/C would cut in and out and not cool at such a low idle. Hard to believe how much gunk builds up on the throttle blade.

 

<{POST_SNAPBACK}>

 

 

 

 

Yeah, thats a pretty common problem, and its cross platform.. I had a 05 Escape that couldnt idle in drive (automatic).

 

Good ol can of gumout, 2 rags later, runs like a champ again.

 

I would take that diagnosis to the service manager, by the way... People wanting to charge that much for something is obscene. And, if the service manager doenst care? Then a nice letter to the owner of the dealership, cc: all the makes he carries, and the better business bureau..

 

-Gonz

[Dans Denali]

Clean the idle air motor.

 

Dan