Symptoms of Excessive Carbon Deposits in the Idle Speed Motor?
3 Answers
Symptoms of excessive carbon deposits in the idle speed motor include: increased fuel consumption compared to before, excessive and unpleasant exhaust emissions, weak vehicle performance, poor acceleration, engine feeling sluggish, difficulty starting the car, and unstable idle speed that fluctuates. Below is additional information: 1. Idle speed control valves are typically in the form of electric valves or motors, installed somewhere in the vehicle's intake manifold. The valve or motor is controlled by the engine control module, which adjusts the idle speed based on parameters such as engine temperature and electrical system load. 2. When the idle speed control valve fails, it can cause various issues with the vehicle, even rendering it inoperable. Generally, a faulty or failed idle speed control valve will produce some symptoms that can alert the driver to potential problems.
Oh, I've got experience with this issue. My car used to have a problem with excessive carbon buildup in the idle speed motor. The engine would shake at idle, the tachometer needle kept fluctuating, and it often made me nervous when stopping at traffic lights. Sometimes it would suddenly stall and need to be restarted. Especially on cold mornings, the car would hesitate for a long time when starting, and if I pressed the accelerator too hard, it would lurch forward while fuel consumption kept rising. I remember last winter being stuck on the highway when the shaking got so bad it attracted a traffic officer who pulled me over. Ended up spending a few hundred to clean the carbon deposits to fix it. The mechanic said a dirty air filter makes it easier for dust to accumulate, so I should change the filter more often and avoid driving in dusty areas. My old German car is particularly prone to this problem.
As an ordinary car owner, this issue is quite frustrating. My car has unstable idling, with RPMs fluctuating up and down. When parked, the engine shakes so much that the seat vibrates, and it occasionally stalls suddenly, leaving me scrambling to restart. Cold starts are the most annoying—stepping on the gas pedal does nothing for a while. It improves slightly after warming up, but fuel consumption has noticeably increased. A friend told me that in cities with heavy air pollution, gasoline quality is poor, and since the idle control valve is positioned deep inside, carbon buildup accumulates quickly. It's better to address it early rather than risk breaking down on the road. Usually, cleaning the carbon deposits or replacing the part will do the trick—it's cost-effective and safe.
