Throttle body valve motor - lumpy idle

ITSFLYBYE

MEMBER
2011 NISSAN VERSA
1.8L
4 CYL
2WD
AUTOMATIC
80,000 MILES

No codes in ECU for anything. Sparkplugs have plenty of life left.

Is it possible for the throttle body valve motor to not throw a code yet not be able to open enough allow a smooth idle? This car does not have an idle control valve.

Idle is "usually" smooth. Every few random seconds the rpms dip a few hundred rpm and goes immediately back up to normal idle. The car does not feel like it is about to die. After x number of random seconds, it does it again. Sometimes it will not even do it at all. It simply sputters for a very brief moment causing a minor jolt in the car.

It happens when in gear (automatic) or in neutral. When in neutral, it is barely noticeable since it is not jolting the car.

Once you are driving, the car is perfectly smooth with no sputtering. This random issue only occurs during idle.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,644 POSTS

Hi,

It can be a few things. My first suspect is the mass air flow (MAF) sensor which is located in the air inlet tube between the air filter and the throttle body. It could also be related to an engine vacuum leak. I attached a pic showing where the sensor is located. First, remove the sensor and clean it. If you go to a parts store, you will find cleaner specific for this job. Don't use car cleaner or brake cleaner.

If that doesn't remedy the issue, then I would check for vacuum leaks. Here is a link that shows how to check:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Try these things first and let me know what you find. Since there are no codes, it becomes a bit more difficult, but if we start with simple things that can cause this type of problem and are inexpensive to do, we may get lucky.

Take care,
Joe

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