Reasons for Vehicle Shaking After Throttle Body Cleaning
2 Answers
Vehicle shaking can generally be divided into two main categories: body shaking and engine shaking. If the shaking occurs immediately upon ignition, it is usually identified as engine shaking, whereas shaking that appears while driving is mostly body shaking. Below is an introduction to the reasons for vehicle shaking: 1. Reasons for body shaking are as follows: (1) Uneven brake disc surface, leading to body shaking during braking along with a bouncing brake pedal phenomenon. This usually occurs due to frequent hard or emergency braking by the driver. (2) Issues with the steering system. Most modern vehicles use hydraulic power steering, and when problems arise in the hydraulic steering mechanism, such as low power steering fluid or mechanical failures, shaking can occur. (3) Problems with the running gear. Out-of-round or unbalanced wheels and tires require inspection in such cases. 2. Reasons for engine shaking are as follows: (1) Aging engine mounts. The engine mounts serve to cushion engine vibrations, and if they become worn or deformed, the engine's shaking will be directly transmitted to the body. (2) Misfiring or cylinder failure, which is the most common cause. The main issues lie with the engine's ignition coils and spark plugs. When the ignition coils and spark plugs fail to fire, shaking occurs, typically noticeable at low to medium speeds with poor acceleration. Checking the spark plugs is advisable in this scenario. (3) Severe carbon buildup in the cylinders, leading to clogged spark plugs and valves, resulting in reduced power and persistent shaking. At this point, a thorough cylinder cleaning is almost necessary.
With years of experience in car repair, I often encounter engine shaking issues after throttle body cleaning, which mainly stem from several causes. Incomplete cleaning leaving residual cleaner can affect sensor readings, leading to unstable idling. The throttle position sensor requires recalibration, as cleaning alters the original parameters; without resetting, the ECU cannot adapt to these changes. Improper installation may cause air leaks, disrupting the air-fuel mixture ratio and triggering vibrations. The ECU's learning process is slow, so it's advisable to drive a few kilometers post-cleaning for system self-adjustment. Check if the idle control valve or mass airflow sensor is concurrently damaged, as these components are closely related. Worn spark plugs can exacerbate symptoms; inspecting them during maintenance can prevent recurring issues, ensuring smooth and safe driving while avoiding unnecessary expenses later.
