Skip the auto shop - Our mechanics make house calls

Q: weird noise with cold air intake and idle

asked by on

I recently installed a cold air intake and everytime i drive it and get to about 1200-1800 rpms the car makes a weird metal noise, sounds like somethings loose also it sounds like metal scraping. And also one other thing is sometimes when the car is warmed up and i turn it on the rpm needle goes up and down and up and down then gently goes below 1k rpms.. It keeps idling high and whats weird is it goes up and down about 4 times. Like major ups and down. Any advice would be nice thanks

My car has 35000 miles.
My car has an automatic transmission.

This is a common symptom of the mass air flow sensor needing to be upgraded due to the increased air intake. The mass air flow sensor operates based upon predetermined stock tuning in the ECM. When the air flow changes, this can cause the jumping in RPM’s due to the imbalanced air/fuel mixture being created by increasing the air flow. I would recommend having an expert from YourMechanic come to your home to diagnose and replace your mass air flow sensor.

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: Key Fob push start not working

Hi there. If you're able to lock and unlock the doors on your Chrysler with the FOB, then the issue with starting it is probably related to either the ignition switch or the ignition relay. If you tried to jump...

Q: Motor swap advice

Hi there. As long as your transmission is a 4L60E, or a 4L80E, then the engines will bolts up to the same transmission. Most of the newer transmission have a replacement bell housing that can be swapped around with different...

Q: Scraping while decelerating

When you hear this noise, does braking have an effect on it? Do you hear it all the time while driving? If your car is sitting still and running, do you hear the noise? Do you hear this while changing...

Related articles

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...
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.