Skip the auto shop - Our mechanics make house calls

Q: Car is knocking when I hit the gas

asked by on

My car is knocking when I hit the gas and is running rough. Could it be a sensor or possibly the timing belt or another belt?

My car has 130000 miles.
My car has an automatic transmission.

A: Hello. Is the Check Engine Light on? A loud...

Hello. Is the Check Engine Light on? A loud knocking noise coming from the engine is not typically a good sign. First, check to make sure all fluids are are the right level, especially the oil. Metal shavings on the oil dipstick can be a sign of a mechanical failure. A knocking noise from the belt drive system may be an idler pulley or one of the components along the belt drive system. If you need help verifying the problem, a certified professional from YourMechanic can come to your car’s location to diagnose the rough running problem and perform needed repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: When my car is at idle in park or neutral the Intake Air Control Valve fluctuates, causing the RPM's to do the same.

Hi there. It sounds as though the idle air control valve (IAC) may be sticking. It is not uncommon for carbon to build up in the valve, the computer will try to overcompensate to correct the slow reaction inside the...

Q: Driving on freeway around 60 mph loud pop then truck died wants to turn over but dont.

answering

Q: Acts like its going to stall during idle, sometimes hesitates to go

It sounds like you have a vacuum leak or intake air leak in the hose from the mass air sensor and the throttle body. If the tube has a crack in it somewhere, it will run rough and when you...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...