Skip the auto shop - Our mechanics make house calls

Q: Prominent vibration throughout van when AC is on

asked by on

My wife's minivan AC blows cold, but the engine vibrates all the way through the steering wheel when it is on, and OCCASIONALLY will vibrate even if the AC is off, though very seldom, and will go away if I cycle the engine on and off a few times. So 99% of the time, it runs perfectly smooth as long as the AC is off. When it is vibrating, there is a slight drop in power. The entire time we've had the van (about 2 years) the AC is always on because the van will blow hot air through the floor vent on the passenger side where the air filter is located if we turn the AC off. Since this problem started, I went ahead and removed the fuse to avoid the whole problem.

My car has 160000 miles.
My car has an automatic transmission.

Hello. The heat issue that you have with the van sounds like you have a blend door issue under the dash. As for the vibration I usually check to see if the idle is getting too low when the AC is on. If it is then I start by cleaning the throttle body. Most of the time that is all that it takes to get the vehicle to run smooth again. If the idle is fine then then I check the engine mounts as that is the most common part to fail and cause this. A bad engine mount will allow the engine to move just enough when it is under load to cause it to vibrate like this. If you need to have this idle vibration checked, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.

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. Prominent vibration throughout van when AC is on

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: Rear brake lights and turn signals not working

It sounds like the bulbs need to be replaced in the rear. I would have a technician, from YourMechanic, come out and replace the bulbs and test the voltage going to the connector.

Q: Repeatedly blowing the same fuse

Hi. I can't help you much without knowing which fuse is blowing. Fuses are designed to blow to protect the circuit in the case off too much current draw. You're correct that a short can cause a fuse to blow....

Q: Car stalls when stopped in traffic

Just because your Check Engine Light is not on does not mean you do not have codes in the computer memory. You could have codes that are called pending codes. These codes mean a problem happened but has not happened...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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 Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.