Skip the auto shop - Our mechanics make house calls

Q: My truck shakes at traffic lights

asked by on

My truck shakes at traffic lights when hot. The shaking isn't that big but I can still feel it. When I stop at a traffic light my truck shakes for a while, stops, and then starts shaking again. The truck drives and runs very nicely, and I haven't had any troubles with it. I don't have any warning lights on my dashboard such as check engine. When the truck is cold it doesn't shake at all but when it gets hotter when the truck idles it shakes. I've noticed that my rpm needle isn't steady when idling it moves up and down just a little bit up and down, thank you for your help.

My car has 143000 miles.
My car has an automatic transmission.

Hi. The symptoms you describe could be a dirty or malfunctioning idle air control valve. Especially when hot, when the engine gets a leaner mixture of air and fuel, the idle air control will have a greater effect on idle and low speed running. In general, it will not set a Check Engine code either. I would recommend having a rough idling diagnostic completed by a mobile professional mechanic, such as one from YourMechanic, to inspect the problem and replace the idle air control valve if needed.

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: I think I may need a new fuel pump but not sure

The fuel pump sits inside the fuel tank in a sump of the tank and should not be starved from fuel supply until you get below about 2 gallons left in the fuel tank. You should have the fuel tank...

Q: the car revs high and at stop signs while slowing down then idles down suddenly and sometimes stalls, whats the cause?

The engine intake manifold seals or the intake tubes between the mass air flow sensor and the throttle body may have a leak that you cannot hear, but could be found using a smoke machine designed to find the leaks....

Q: New battery dead and doesnt take charge

This may be a sign of a weak battery, a failing voltage regulator or failing alternator. If the battery was charged at one point, used and then sat for a couple of months without activity following this, this may have...

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...
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...