Buick Park Avenue Stalling at Idle, IAC Valve Issues

Had the exact same symptoms on my 2004 Buick LeSabre last summer. The engine stalling at idle turned out to be severe carbon buildup in the throttle body and intake manifold. The initial diagnosis showed the idle air control valve wasnt responding properly due to heavy contamination. After a complete intake cleaning service, the idle speed stabilized and the stalling issue disappeared completely. The check engine light was cleared and never came back. This is a fairly common problem on these engines once they pass 150k km. The carbon deposits gradually build up, restricting proper airflow through the throttle body. When left untreated, it can lead to serious engine performance issues and eventually damage the idle air control system. The repair involved: Complete throttle body removal and cleaning, Intake manifold decontamination, New gaskets installation, Idle speed reset and computer adaptation For these symptoms, its important to get it properly diagnosed and cleaned rather than just resetting the check engine light. The stalling will only get worse if the underlying contamination isnt addressed. Any competent general auto repair shop should be able to handle this service. Its not an overly complex repair but requires proper cleaning techniques and careful reassembly to prevent vacuum leaks.

Thanks for sharing your experience. Mine got fixed about 8 months ago and the engine idle has been perfect since. The IAC valve replacement and thorough cleaning of the throttle body solved all the stalling issues. Just wondering, do you remember roughly what you paid for the complete service? Also, has everything been running smoothly since the repair, or have you noticed any other engine performance issues?

Thanks for following up. Yes, my total repair bill came to 425€ for the complete intake system cleaning and IAC valve work. The contamination was pretty severe, but the repair was definitely worth it. The idle speed has been rock solid since getting the work done, with no signs of engine stalling or rough running. The car idles perfectly whether cold or hot, and the engine performance is noticeably smoother overall. The mechanic mentioned doing regular fuel system cleanings can help prevent the air intake from getting gunked up again. Since having the IAC valve fixed and intake cleaned, I havent had a single issue with idle control or any other engine performance problems. Its good to hear your repair was successful too. These idle control issues can be really frustrating, but once properly diagnosed and fixed, they typically stay resolved as long as basic maintenance is kept up.

Just got back from getting my car fixed, what a relief! The repair took about 4 hours but was worth every minute. Turned out the throttle body was completely clogged with carbon deposits, making the engine idle terribly. The mechanic did a deep clean of the entire intake system and replaced the faulty IAC valve. Total cost was around 500 for parts and labor, which seemed fair considering the amount of work involved. The car runs like new now, no more stalling at stoplights or rough idling. My engine idles perfectly smooth whether cold or warm. Really glad I found a better shop this time. The mechanic showed me all the gunk they cleaned out and explained everything clearly. They even gave me some tips about using fuel system cleaner every few months to help prevent future buildup. Amazing what a difference proper diagnosis and repair can make. Should have done this months ago instead of wasting time at that first shop. Lesson learned about finding the right mechanic for idle control issues!