Skip the auto shop - Our mechanics make house calls

Q: Shaking and revving upon startup.

asked by on

The car shakes and the engine revs upon startup.

A: It is normal for the engine to rev a bit hi...

It is normal for the engine to rev a bit higher than normal when a car first starts up. But, after a few seconds it should come back down to normal. In cold weather, it might stay high for a few minuets. But, if the RPMs are going very high then there is a problem. The idle should go up a few hundred RPMs not a few thousand. A large vacuum leak can cause symptoms similar to what you are describing. A faulty or stick Idle Air Control Valve could also cause this. If you think the RPMs are going up abnormally I would suggest getting a technician to have it inspected for you.

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!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Engine knocking

Knocking in your engine, also described as pinging, can mean one of several problems. Some may be easily fixed while others may indicate major damage. The knocking sound often occurs when the fuel and air mixture is incorrect, which causes...

Q: Flashing check engine light - 2005 Ford Ranger

Hey there. You should probably have another look at your plugs and wires to see if the work was done correctly. Something may not be well connected causing an intermittent misfire. The Check Engine Light comes on steady when the...

Q: When brake is pressed, the car shakes

Hello! If your engine is emitting blue smoke from the exhaust the problem will probably be some form of internal engine damage or wear. More than likely it will be worn valve guides or piston rings. Both of which will...

Related articles

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...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.