Why does the Accord shake when idling with the air conditioning on?
2 Answers
The reasons and solutions for the Accord shaking when idling with the air conditioning on are as follows: 1. Severe engine carbon deposits: Carbon buildup in the engine is the main cause of car shaking. When there is too much carbon deposit inside the engine, the gasoline sprayed by the fuel injector during a cold start will be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making the engine prone to idling. It is necessary to regularly clean the fuel system, check the idle speed control valve, and clean the throttle body. 2. Ignition system failure: Excessive carbon deposits on the spark plugs or overly large ignition gaps can lead to ignition failure. It is necessary to promptly check the wiring and replace the spark plugs if needed. 3. Fuel pressure issues: Abnormal fuel pump supply pressure or incorrect readings from the intake pressure sensor can cause poor fuel pump performance, leading to body shaking. It is essential to immediately inspect the fuel pump and pressure sensor and clean the fuel pressure lines.
I think it's quite common for the engine to idle roughly when the AC is on, mainly due to the sudden increase in engine load. When the AC compressor kicks in, it draws additional power from the engine, causing unstable idling—just like how a person would pant when suddenly doing heavy labor. The Accord's engine itself is highly precise, but over time, issues like carbon buildup in the throttle body or aging spark plugs can become more noticeable. Carbon deposits disrupt the air-fuel mixture ratio, leading to poor ignition, which becomes more pronounced under the increased load from the AC. I've seen cases where owners promptly cleaned the throttle body or replaced spark plugs, and the issue improved. Don’t just blame the AC—the core issue lies in engine maintenance. It’s advisable to regularly inspect these components to prevent minor problems from escalating into costly and time-consuming major repairs.
