What Causes the Buick Regal to Shake During Cold Starts?
2 Answers
The reasons for the Buick Regal shaking during cold starts include low temperature and issues with the air-fuel mixture. Low Temperature: One problem faced during cold starts is low temperature, especially in cold northern regions. If the spark plug gap is too large, the ignition energy may be insufficient, leading to ignition failure. This can cause individual cylinders to fail to ignite properly, resulting in weak starts and shaking. Air-Fuel Mixture Issues: Shaking during cold starts can also be caused by the air-fuel mixture being too lean or too rich. Problems with the air-fuel mixture may arise due to faults in the closed-loop control system. Since the exhaust pipe temperature hasn't reached the required level during a cold start, the oxygen sensor may not be at its working temperature or could be damaged, leading to shaking issues during cold starts.
I've been repairing cars for over a decade and have encountered many cases of Buick Regal cold start shaking. The main causes are usually those few, such as severe carbon buildup on the spark plugs, leading to insufficient ignition energy; or clogged fuel injectors, causing uneven fuel injection during cold starts. Aging ignition coils are also a hidden danger as they affect spark stability. If the engine mounts are loose or worn, they can amplify the vibrations. Carbon buildup is even more common, as insufficient lubrication during cold starts can cause the valves to open and close improperly. Don't underestimate this issue—delaying can worsen engine wear. I recommend regularly checking the spark plugs, changing the oil every 20,000 kilometers or so, and using a diagnostic tool to read the data if shaking occurs to confirm the root cause. You can also use fuel additives to clean carbon deposits—prevention is always better than repair.
