Skip the auto shop - Our mechanics make house calls

Q: car vibrates badly at 40+ but only when gas is being applied

asked by on

car vibrates badly at 40+ but not when gas is not being applied

My car has 190000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. Vibration and shaking is typically associated with a poor combustion taking place inside of the cylinders. This can be spark, air, or fuel driven. Think of it this way, the vehicle has a constant supply of spark and fuel, what the computer controls with the throttle is the air intake. When you take your foot off of the accelerator, there is a valve that is used to steadily drop the air intake to the engine rather than just cutting it off and stalling the engine. This is the idle air control valve, and it may be failing. You may also want to test your spark system and fuel pressure if the issue is not related to this valve. Only further testing will tell.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. car vibrates badly at 40+ but only when gas is being applied

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: Heater blowing cold

If the vehicle is neither overheating or running too cool / taking too long to reach operating temperature, the thermostat is most likely opening and closing properly. Be certain the coolant is at the proper level and both hoses to...

Q: Vibration when applying brakes and when steering.

This may be a sign of warped brake rotors and/or potentially failing wheel bearings. When your brake rotors get hot due to the heat caused by friction, they can develop hot spots in them which causes an uneven surface area....

Q: Hello,my name is Sandra, I have a'05 Pontiac G6,it has a sunroof and water is leaking on the floorboards on both sides,of back. I'

Water is like electricity. It follows the path of least resistance. Manufacturers have learned to make water flow over or through the car easily to keep it from getting to the interior. Hearing water sloshing inside any of the doors...

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 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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...