About 6 months ago my Mazda 3 began revving extremely high on start up. This would sustain for a good 20 seconds, sometimes longer. This is also accompanied by a lot of vibration and buzziness. I know Mazdas rev high on start up, but not this high and for this long. Anyone have similar problem or ideas about what this might be?
Whenever there’s an idle problem with an engine with an electronic throttle body as with your vehicle
You try to clean the electronic throttle body.
Tester
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How high were the revs?
Did this coincide with low temperatures?
Did “goosing” the gas pedal help to reduce the revs at all?
Tester is probably correct that you need to clean the throttle body, but I am still curious about your responses to my questions.
It didn’t coincide with low temps I don’t believe. My memory is it started in late spring. I never goose the gas pedal, but I can try that and see what effect it has if that might give more insight to the problem. The revs went up to 5-6000. There is one subtle difference from the normal high rev associated with this car, and that is-it revs to a normal high then sort of shoots up to those super high rpms and stays there for a while. Sometimes even after I start driving the car.
I’ll try cleaning the throttle body. Thanks for the ideas!
Is it absolutely necessary to remove the throttle body from the car or can I clean it while mounted to the car?
That is absolutely not normal, even with cold weather, and is going to damage the engine unless you get it corrected very soon. Revs that high with a stone-cold engine are… not good.
Watch this.
Hint: I use an old battery powered tooth brush to scrub the carbon away.
Tester
Our old Mazda was having a different issue but the mechanic had my dad pump the gas a few times while he used a can of throttle body cleaner which helped a bunch, in the parking lot without taking the throttle body off. We just had a slightly sticky throttle body that was causing a stall if you took your foot off the gas. ’
Yikes, that’s not what I wanted to hear haha. I have noticed a knocking sound when idling shortly after the revving issue began. The knocking gets less intense when I’m driving but it’s still there.
Very helpful. Much Thanks!