What to Do When the Car Makes a Zizi Sound When Pressing the Accelerator?

[NorahRose]

When the car makes a zizi sound when pressing the accelerator, here are the inspection methods: 1. It could be the sound of the fuel pump working. Sometimes, the fuel pump may produce a zizi noise when operating, and the sound becomes louder as the accelerator is pressed harder. 2. It might be a faulty clutch release bearing. Try pressing the accelerator; if the car runs normally but does not accelerate, this indicates obvious slipping, mostly due to worn clutch plates. If there is a zizi noise, the clutch bearing may be damaged. 3. Check if there is any air leakage in the engine's intake pipe. Increasing the air intake by pressing the accelerator can cause a zizi noise due to air leakage. Check if the air filter is properly installed and if there are any damages or looseness in the intake pipe. 4. Check if the engine belt is aged, loose, or slipping, and replace the belt tensioner if necessary.

[DeDawson]

I encountered a similar situation last week, and that buzzing sound is indeed quite annoying. For older cars, prioritize checking the intake system: open the engine compartment, start the car, have someone step on the accelerator for you, and listen closely to locate the source of the sound. It's highly likely that a vacuum tube has cracked and is leaking, or the air filter box lid isn't sealed properly. Plastic parts are particularly prone to developing small cracks as they age. Another possibility is that the engine cover is loose and resonating. Start by inspecting these areas yourself, and try spraying some WD40 on the clamp connections to see if the noise changes. If you still can't find the issue, you'll need to put the car on a lift to check if the exhaust heat shield is loose or if the underbody panel screws are loose and rubbing against the driveshaft. Also, don't overlook the motor sound from the electronic throttle pedal itself—that thing can also make noise if it's lacking lubrication.

[LaLouis]

I've encountered this issue when working on modified cars as well, the hissing sound is really annoying. The prime suspect is usually the piping around the turbocharged car's blow-off valve, where aging and cracked rubber hoses are particularly prone to air leaks and noise. It's also common for clamps to not be tightened properly after intercooler removal, causing the pipes to hiss when they expand under heavy throttle. Another culprit could be excessive carbon buildup on the throttle body, causing the butterfly valve to operate roughly and produce a metal-on-metal scraping sound like nails on a chalkboard. If you've modified the exhaust, don't forget to check the rubber hangers on the muffler section, as they can rub against the chassis when the exhaust shakes. The most troublesome issue is the brake vacuum booster's check valve - when this fails, it creates a synchronized hissing sound under your foot. I recommend using a can of carburetor cleaner to spray around pipe joints; wherever the sound changes abruptly is likely the leak point.

[Tina]

After spending a long time in the repair shop, I've noticed that electronic throttle noises often occur near the pedal. It could be due to rust or lack of lubrication in the pedal return spring—just spray some silicone lubricant. However, don't overlook the more troublesome throttle pedal position sensor; wear in its potentiometer can cause electrical noise. Another issue with drive-by-wire throttles is interference between the wiring harness and the chassis, especially if modified floor mats or thicker carpets compress the cables, causing the harness to rub against the frame when the throttle is fully depressed. It's recommended to remove the driver's side trim panel to check the wiring harness routing and secure it with nylon zip ties. In some models, the brake light switch and throttle cable are too close, leading to interference.