Has anyone noticed a noise in there engine like a knocking noise while you are in idle or driving. Also, my AC cycles on and off every 20 seconds and clicks loud each time it does it. Is anyone else experiencing this problem. I only have 700 miles.

 

Yes I have a clicking noise with AC coming on and off as well. Assuming its normal. I can only hear it when the windows are down.

 

You can heat mine with the windows up and it is so annoying. What should I do?

 

Yes mie has the same AC Clutch noise. I suspect the gap is too large betwwen the clutch and the pulley. I can hear mine over the radio. I had posted the same questions a few weeks ago....mine also exhibits a clicking noise at idle. I think it may be related to the variable cam timing. I paln to see my dealer soon to try to resolve. Neither noise is that pressing to me, more annoying for 35000 than any thing else

 

Well I am glad that I am not crazy then! But I took it to my dealer and the chief mechanic said the engine noise is normal. He said "all the new trucks are engineered differently and you are going to hear things that you have not heard in the past." Yeah right, let me know if you take any actions and they get resolved. Thanks

 

I love answers like that from supposed master mechanics as I am also one myself. I would at least respect an answer of "I don't know" vs "Thats a normal sound" (my favorite)
It's a new vehicle and this engine is quite a bit different than the one it replaces. They need to call the tech assistance line to get further advice. If they don't, suggest to them that they should read up on the debacle that GM is going through right now on their truck lines with engine tick/knock......
www.auto.com

 

Having not heard your noise I can't say for sure, but I would guess that your knocking noise is normal. The newer engines are running very short piston skirts (for mileage and emissions) and they seem to make more of a "rod knock" sound. This should be much more noticible on a cold start, especially on a cold day. If you want to see one that's really bad, start a 5.3L GM truck on a day below freezing. As to your A/C, does it cool properly, it sounds like you might be low on freon causing it to cycle.