Q: I have a 2014 GMC Denali. Every time the rpms are at 1000, coming to a stop or coming out of a stop, something vibrates.

asked by on July 20, 2017

My GMC Acadia has been making a vibrating noise when coming to a stop or especially when coming out of one right at 1000 RPMs. I only hear/feel the vibration at 1000 and slightly at 2000RPMs. Also when braking the RPMs are fluctuating up and down and seem like they are getting stuck in a gear just a bit. Any ideas on the noise and fluctuating RPMs? Note, this is not a brake or wheel vibration. It appears to be coming from the engine.

My car has 42000 miles.
My car has an automatic transmission.

If the noise only exists when the vehicle is moving at the RPM values you cite, the vibration is probably in the drive train. If the vibration occurs in park though, again at the cited RPM values, then it is due to a rotating engine/transmission component such as the harmonic balancer or torque converter. There’s also a possibility there could be a motor mount defect. The RPM fluctuation on braking could be due to a transmission issue such as faulty valve body/shift solenoid controls. However, engine controls, such as the throttle position sensor, idle air control valve and so forth would be evaluated, too. To resolve an issue like this, you can request a vehicle vibration diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Brake line rusted causing leak
Hello. When metal brake lines rust through and start leaking they must be replaced. There is no way to patch or repair the line without replacing it. If one line has rusted through then I would inspect them all and...
Interior light won't turn off
If one of the lights inside the vehicle is not turning off, then there is likely a short in the wiring or switch for that light. As wiring problems can sometimes be hard to diagnose or detect, I would recommend...
Rear right tire is seizing up
Hello. If the tire is seizing up it is typically from the brakes. The drum brakes on this car will cause this if they are worn out, or if one of the return springs are broken. It can also occur...
Car stalls when it is about to stop at the traffic light
The most common problem is the tube between the air filter and the throttle body has an air leak that can cause the stalling. Try to get the computer scanned for codes and if you have lean codes, then look...
Loss of power won't go over 35 mph - 1999 Dodge Ram 1500
This may be a sign of low fuel pressure, a failing mass air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement) or potentially a clogged catalytic converter (https://www.yourmechanic.com/services/catalytic-converter-replacement). As you may already know, the catalytic converter converts toxic exhaust gases into less harmful pollutants that...
Car cranks strong but will not start - 2000 Subaru Outback
Hi there. It sounds like you've certainly done some good checks. However, what was the fuel pressure? Each manufacturer has a specified fuel pressure required for the engine to run. There can definitely be plenty of fuel coming out of...
When I turn the switch to use a turn signal, a buzzing sound starts and it may blink once every 8-10 seconds
Odds are you have a faulty signal/hazard flasher relay. Although the relay is an electrical component, the internals are basically mechanical. The relay does just what the name implies. It relays power and the signal from the signal switch to...
My car's shaking and losing oil fast, what's going on
Hello, thank you for writing in. The shaking is likely caused by a misfire and engine error. You may also be dealing with multiple issues at once, or the oil leak may be causing the running issues. If the spark...
03 Nissan Altima wouldn't accelerate over 50 mph.
Hi there. This sounds like the gas pedal position sensor or the throttle body position sensor is not working properly. You can try manually resetting the gas pedal position sensor. To do this, perform the following: Turn on the ignition...

Related articles

A Buyer’s Guide to the 2012 GMC Terrain
When When you look at smaller SUVs like the Honda CR-V and the Toyota RAV4, do you wish for just a little bit more space? But then when you look at the larger SUVs like the Ford Explorer or the...
A Buyer’s Guide to the 2012 GMC Acadia
When When it comes to finding the right SUV for your family, it seems like there are always a lot of compromises to be made. One vehicle is so performance and off-road oriented that you can’t imagine taking your kids...
A Buyer's Guide to the 2012 GMC Yukon Hybrid
The The GMC Yukon is about as big and powerful as any SUV can ever get. However, in the past, that also meant paying a large sum every time you hit the pump. GMC has addressed this problem with their...