Skip the auto shop - Our mechanics make house calls

Q: fluctuating idling and slippage

asked by on

Truck started acting as though the transmission was slipping, going down the highway it would fall a gear or would up shift hard but now when it idles it will fluctuate high and low rpms. Doing some research online found blogs that say it could be the master airflow sensor however nothing looks wrong with it found a crack in the radiator so replace the radiator still idling high and low. Possibly going to replace the master airflow sensor but after that I have no idea what to do

My car has 174000 miles.
My car has an automatic transmission.

A: Hi there, thanks for writing in, The mass ...

Hi there, thanks for writing in,

The mass airflow sensor is used by the engine control module to determine how much air is coming into the motor so it can properly decide how much fuel to use for optimal power and fuel efficiency. If the mass air flow is faulty or is giving an incorrect signal, it can significantly affect the operation of the vehicle. It is definitely a possible cause of the issue you described, though it is not the only one. If you want to avoid spending money replacing parts that may not be faulty, I would suggest contacting a professional technician, such as one available from YourMechanic, to properly diagnose your concern.

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: Dodge Ram 1500 won't go over 20 miles it's a 2007

Hi Lisa. Without knowing specifics about what may have occurred prior to your truck only going 20 mph, it's hard to give you accurate advice. It's possible that your truck may have a transmission issue, which typically triggers a limp...

Q: Engine caps at 3000 rpm's, no cel light, and no smoke of any color. Uncaps when restart the engine.

Hi there. There could be an issue with the fuel system causing the engine to stumble and bang at times. Check the fuel / water separator on the vehicle and see if its been replaced before. If not, then the...

Q: Heater blowing lukewarm air. Had thermostat and gasket changed plus heater core back flushed. No change.

The heater is reliant on the engine temperature getting up to and maintaining normal operating temperature. Once this is verified then you can check both heater hoses in and out of heater core with blower on low speed and heater...

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
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.