Skip the auto shop - Our mechanics make house calls

Q: The car revs while not moving, the check engine light is on

asked by on

The check engine light is on, on the Head-up Display of my car. It revs up and down when the car is not moving. I checked the cylinders as I was told at the dealership that if they misfire, this can happed. I checked that out and the same problem happened. I also had the transmission fluid changed but to no avail. I took it to the shop again and they told me it is the intake manifold causing this. I would like some advice and another opinion about the cause of this issue. Thank you.

A: Hello. If the engine speed is going up and ...

Hello. If the engine speed is going up and down as the vehicle is sitting there and running, then it is not a transmission problem. It can be an intake manifold issue as they mentioned, as I have seen a lot of these fail and cause this. Most of the time though, it is caused by a faulty air flow sensor. When this is not reading right, then the computer cannot control the idle. I would scan the computer for codes to see for sure what the computer is seeing. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose your Check Engine Light and proceed with appropriate repairs.

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: What Are the Top Transmission Problems That Should Never Be Ignored?

Ignoring problems with cars is like ignoring problems with teeth. Waiting longer usually just results in more pain and expense. Seeing transmission fluid on the ground under your vehicle should get your attention right away. Transmission fluid is usually reddish-brown....

Q: power steering not working

You probably know this already, but I must mention that driving with the faulty power steering is very dangerous. This is definitely not an issue that can wait. The trouble could be in the power steering pump, belt/tensioner, or steering...

Q: Car stalls, hesitates, misfires - 1998 Oldsmobile Delta 88

There are several potential problem areas (besides fuel supply which you seem to have addressed), which could cause lean running and the symptoms you describe. A dirty throttle body, failing mass air flow sensor, vacuum leak, or bad oxygen sensor...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...