Rough Idle at stoplights

[Ayee__Jay]

As I am driving, for a while I've realized that the car my dip in RPMS a little but it wasn't ever anything bad or eyes raising, but NOW when I get to a stoplight after driving the car for a while (majority of the time of me driving in sport) when I get to a standstill the car will randomly (not all the time but about 70% of the time) dip in rpms drastically to the point it feels like its going to stall but a few seconds later it comes back up normal and does it all over again. The one thing that I have learned that I haven't seen in threads is when I turn my A/C off, the rough idling goes away. I've only attempted this about 3 times but every time it has gone off. Does anyone know the problem?

Bone stock btw.

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[brianbr]

As I am driving, for a while I've realized that the car my dip in RPMS a little but it wasn't ever anything bad or eyes raising, but NOW when I get to a stoplight after driving the car for a while (majority of the time of me driving in sport) when I get to a standstill the car will randomly (not all the time but about 70% of the time) dip in rpms drastically to the point it feels like its going to stall but a few seconds later it comes back up normal and does it all over again. The one thing that I have learned that I haven't seen in threads is when I turn my A/C off, the rough idling goes away. I've only attempted this about 3 times but every time it has gone off. Does anyone know the problem?

Bone stock btw.

Yep it's the gen3 curse.

 

[W.O.T. Stang]

Happens to me very randomly. Maybe once a month. I don't worry about it. If you tap the gas it'll smooth itself out. There is a thread about it here somewhere.

 

[Dana Pants]

It seems there are many potential root causes. For me it took nothing more than cleaning the throttle body to solve.

 

[Ayee__Jay]

Happens to me very randomly. Maybe once a month. I don't worry about it. If you tap the gas it'll smooth itself out. There is a thread about it here somewhere.

wish it was that easy lol continues anytime I go on a 15+ minute drive

 

[Ayee__Jay]

It seems there are many potential root causes. For me it took nothing more than cleaning the throttle body to solve.

I've heard that and I've also got a buddy who said once he got an oil change it stopped so we shall see this weekend as i am about due for one anyway, and i'll check the throttle body

 

[coz0502]

I've heard that and I've also got a buddy who said once he got an oil change it stopped so we shall see this weekend as i am about due for one anyway, and i'll check the throttle body

I had this problem, or a very similar one. One day I started the car and it was fine during the higher RPMs from a cold start up, but starting varying RPMs once it dropped to normal RPM range. I pulled the airbox out, cleaned the filter and sensor and also wiped down the throttle body but did not remove.

There was quite a bit of junk in the throttle body that was evident on the rag I used. Put everything back together and problem solved. I'd suggest starting here, it cost me nothing but time since I had some cleaner from a mechanic friend.

 

[Ayee__Jay]

I had this problem, or a very similar one. One day I started the car and it was fine during the higher RPMs from a cold start up, but starting varying RPMs once it dropped to normal RPM range. I pulled the airbox out, cleaned the filter and sensor and also wiped down the throttle body but did not remove.

There was quite a bit of junk in the throttle body that was evident on the rag I used. Put everything back together and problem solved. I'd suggest starting here, it cost me nothing but time since I had some cleaner from a mechanic friend.

Definitely was gonna check the throttle body and MAF sensor out this weekend. It's just weird because as soon as I turn my air off it stops and i turn it right back on and go about my way but obviously lol something's a problem. Did you disconnect the battery before cleaning?

 

[coz0502]

Definitely was gonna check the throttle body and MAF sensor out this weekend. It's just weird because as soon as I turn my air off it stops and i turn it right back on and go about my way but obviously lol something's a problem. Did you disconnect the battery before cleaning?

No I didn't disconnect the battery, but thinking about it now. Maybe I should have??

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