GMC Acadia Stalling Issues Linked to IAC Valve

Having faced almost the exact same issue with a 2006 GMC Envoy last year, I can share my experience. The symptoms were identical, unstable engine idle and frequent stalling, especially after the engine warmed up. First, the error codes pointed to an IAC valve problem, but when my workshop did a thorough check, they discovered the intake system was heavily contaminated. This was causing irregular air flow and making the car idle very rough. The complete service included: Cleaning the entire intake system, Testing the IAC valve functionality, Adjusting the idle control settings, Full diagnostic scan Total cost was 425 Euro and it completely resolved both the stalling engine and irregular idle issues. The car has been running smoothly since then. Based on your description, it sounds very similar, but could you share: Current mileage on your Acadia, When did the stalling first start, Does it happen more when the engine is cold or warm, Any unusual sounds during idle This information would help determine if your case matches what I experienced with the intake system contamination.

Thanks for sharing your detailed experience. I am dealing with this stalling issue at 149391 KM. The throttle body had a similar diagnostic report, lots of carbon buildup affecting the idle speed. Getting a quote for a thorough cleaning and IAC valve testing next week. Good to hear cleaning resolved your stalling problems without needing major parts replacement.

Thanks for the mileage details, that matches almost exactly when my Envoy started having idle control issues. The carbon buildup in the throttle body is a common problem around 150000 KM, and it definitely affects how the IAC valve functions. When my shop did the cleaning, they showed me the before and after of the throttle body, the difference was remarkable. The carbon deposits were severely restricting proper air flow, causing the engine stalling you are experiencing. Quick tip: After the cleaning service, the engine idle took about 100 KM to fully stabilize as the IAC valve and throttle body adapted to the restored air flow. If you notice slight idle fluctuations right after the service, this is completely normal. For preventative maintenance, I now use a fuel system cleaner every 20000 KM. This has helped maintain stable idle speeds and prevented new carbon deposits from affecting the throttle body performance. Let us know how the quote comes back and what they find during the inspection. The cleaning service should be much more cost-effective than replacing parts if carbon buildup is indeed the root cause of your stalling engine.

The cleaning service quote came in at 380 Euro, which seems reasonable based on your experience. After inspecting the air intake system, they confirmed heavy carbon deposits are affecting the engine idle. They will do the full system cleaning and IAC valve testing next Tuesday. Really appreciate your detailed feedback about the adaptation period after cleaning. Good to know the idle might take some time to fully stabilize. I will pick up some fuel system cleaner to use regularly after this service, smart tip for preventing future buildup and maintaining proper air flow. The stalling has definitely gotten worse lately, especially at warm idle, so I am hopeful this thorough cleaning will resolve the issues like it did for your vehicle. Will report back after the service to confirm if it fixed the engine stalling problem. Thanks for helping me avoid unnecessary parts replacement and pointing me toward the likely root cause.