Q: Car shakes past 70 mph, but only when given gas

asked by on October 31, 2017

The car shakes past 75 mph, but only when accelerating or maintaining speed. Coasting stops the vibration. There's also an issue where the car will stop receiving power from the engine randomly. It will do it during acceleration, maintaining speed, and cruise control. Sometimes giving it more gas will cause the engine to rev up but no power to be given to the wheels, but sometimes the engine does not rev up. Usually this lasts 2-3 seconds.

My car has 198000 miles.
My car has an automatic transmission.

Faulty motor mounts are a possibility but suspension faults, such as worn struts, can also cause shaking at high speed. If the problem is suspension related, it may occur during acceleration versus coasting because during acceleration the suspension geometry (running angles) accentuate, or make apparent, the suspension fault (typically a loose or worm part). Failure to accelerate, when engine RPM rises, can be due to slippage in the transmission and that can be due to faults in the torque converter, clutch pack or the hydraulic controls (e.g., inadequate line pressure). With regard to the shaking, there is also a possibility that such is due to an engine management/controls fault, that is once engine speed passes a certain RPM it is the engine itself that is operating poorly and vibrating under load.


The bottom line is you should request a vehicle vibration diagnostic. It is possible to use remote chassis ears (wireless microphones with an in-cabin receiver) to narrow the origin of the vibration and, if it gets really complicated, there are frequency domain analyzers that can take the noise from the vibration and decompose it to the most likely mechanical sources. My guess is, if you request the diagnostic, it will probably not get that complicated because, from what you are describing the vibration is marked, and consequently to a trained mechanic the likely origins will be obvious. If you have additional concerns or a follow-up on this, don’t hesitate to re-contact YourMechanic.

Was this answer helpful?
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

Ignition makes clicking sound

This can be caused by either a low battery charge level, or a loose connection in the starter circuit. The battery needs to be fully-charged, and load-tested, to ensure it is not the issue. All starter wires need to be...

1997 chevy monte carlo after new battery car wont start

A no start condition after a battery replacement can be caused by the theft system or the computer or ignition module may have been damaged during the process of the battery going bad or jump starting. I recommend having the...

Why does my tire sounds so loud when I turn my wheel?

Hello. It all depends on the sound you are hearing. If it is a whining sound, then you may be low on power steering fluid caused by a leak in the system or a defective power steering pump. If the...

Related articles

A Buyer’s Guide to the 2012 Toyota Prius Plug-In
Toyota Toyota definitely isn’t sitting on its laurels where hybrid cars are concerned. To compete with other electric cars like the Chevrolet Volt and the Ford Focus Electric, the 2012 Toyota Prius Plug-In gives car buyers a higher-mileage vehicle with...
A Buyer’s Guide to the 2012 Toyota Prius
Since Since they introduced the Prius, the very first mass-market hybrid, Toyota has been leading the auto industry in hybrid vehicles, and continues to do so in 2012. For this model year, the Prius saw some exciting new options, including...
2012 Toyota Prius vs. 2012 Chevrolet Volt: Which One Should I Buy?
While these two vehicles are both certainly cost-effective to drive, they can be difficult to compare due to the Prius’ entry in the mid-size category and the Volt living squarely in the compact car category. Both of these vehicles are...