Cadillac XT5 Stalling Issues Traced to IAC Valve

Having some experience with engine stalling issues, I had a similar problem with my 2019 Cadillac XT4. The symptoms were nearly identical, unstable idle and stalling when stopping. After taking it to a workshop, they found the intake system was heavily contaminated, affecting the air valve and overall idle control. The IAC valve wasnt working properly because of carbon buildup. The fix included a thorough intake cleaning service and IAC valve inspection, which resolved the car idle problems completely. The total repair cost was 425€, including diagnostics and cleaning. Since then, the engine stalling has completely stopped and the idle is smooth again. Your symptoms sound very familiar, but to provide more specific advice, could you share: Current mileage, Whether youve noticed any other warning lights, If the problem started suddenly or developed gradually, What fuel grade youre using, When the last maintenance service was done This information would help determine if youre dealing with the same intake contamination issue I experienced.

Thanks for the input on the IAC valve issue. My XT5 just had its latest service 3 months ago at 85852 KM, and they did mention the idle control system looked good at that point. It's concerning the idle speed problems started so suddenly despite the recent checkup. I'll get it checked out soon to avoid any further engine stalling issues. Good to know about the potential carbon buildup affecting the idle, I'll mention that to the techs when I bring it in.

The sudden onset of idle problems despite recent service is indeed concerning. When my XT4 developed similar issues, they also appeared quite abruptly even though everything seemed fine during previous inspections. The throttle body and air intake system can get contaminated rather quickly in some cases, even with regular maintenance. In my experience, the service records showing a clean IAC valve just months prior actually helped narrow down potential causes. The techs focused on checking for rapid carbon accumulation, which can happen due to several factors like driving patterns or fuel quality. The diagnostic process revealed significant buildup had occurred in just a few months. The engine stalling symptom you describe matches exactly what I experienced, everything running smoothly at higher RPMs but problematic at idle. Even with regular maintenance, these components can sometimes need attention between scheduled services. Would suggest having them specifically check the throttle body and air intake system for contamination, as cleaning these areas resolved the stalling completely in my case. This type of inspection usually costs less than a full IAC valve replacement if that turns out to be all thats needed.

My XT5 has about 95000 KM now, and no other warning lights have appeared besides the check engine light. The stalling started about a week ago with no prior warning signs. I always use premium fuel as recommended, and like I mentioned, the last service was just 3 months ago. The sudden nature of the engine idle issues is whats most puzzling, especially since the idle control system was checked during maintenance. Based on your experience with the carbon buildup affecting the IAC valve and air intake, I will definitely have them inspect those components first. The 425€ repair cost you mentioned seems reasonable if it completely fixes the engine stalling problem. I am hoping a thorough cleaning of the throttle body and intake system will resolve my idle issues as well, rather than needing a full IAC valve replacement. I will schedule an appointment this week to get it checked out before the stalling gets any worse. Thanks for sharing your repair experience, it helps to know what to expect when I take it to the shop.