Engine stutters when turning on ac/heat

[Ericsch83]

Enginer stutters whenever I turn on the heater, a/c unit. Rpms get below 1k when idling, engine feels like it's about to stall out. When driving there's no real noticeable problem when running the a/c

 

[Hardwareman]

Check your IAC valve. This happened to me before and that's what ended up fixing it.






Allen

 

[Ericsch83]

checked the iac, disconnected it and the engine started to stall so looks like it's working properly. Upon further inspection it is now doing this when the car is actually driving now, not just when idling. There's a click noise, the rpms get real low, then it rev's back up to normal. Then a click, rpms get low, then back to normal, and repeat.

 

[Hardwareman]

Sounds kind of normal, like your A/C clutch is cycling off and on.

You may need a tune up if you have'nt done one in a while. If it's cycling off and on rather quickly then you may be low on refridgerant.





Allen

 

[sean9721]

My truck does the same thing. I was waiting on my sister at the middle school. My windows got fogged up. I crunk up the truck and put the defroster on full. The A/C clutch was cycling on and off real fast. My truck idles at 750. When the clutch cycles on the RPMs drop to about 500. The truck starts shaking like its going to stall out. I do know that im low on freon so thats probably what the problem is.

 

[wileyz62]

A/C cycling

Just wanted to add.Yep,my 2000 3.0 did the same thing.And it was the IAC,which compensates idle for loads.