Frs idle rpm fluctuation, vibration and fan/compressor noise, normal?
 

Hi all, very new here. I have a 2014 Scion FRS auto. recently noticed when the car is idling at working temperature with AC on, I can periodically (about every 7-10sec) hear the fan/compressor kicks in and makes a rather loud noise for couple secs. normally my car idles stably at 650rpm. whenever the compressor/fan noise comes alone, the rpm would jump to 900-1k, then quickly drops back within couple seconds, then repeat. Also a noticeable vibration on the steering wheel.

I brought my concern to the dealership but every time they tried to convince me this is normal. Is it really a normal phenomenon? Should this be regarded as rough idling?

Thank you a ton in advance!

Seems so. Mine also gets noisy at idle, and rpm sometimes drops to near 500 and back.

very normal....4 banger & not the heaviest flywheel..happens with MT too

Hi szjalo and welcome to our forum - :clap:

What your car is doing is quite normal. When the AC compressor engages, that puts an extra load on the engine and the engine increases in rpm to deal with the extra load (so it won't die). Then, the rpms settle back.


humfrz

Super normal. I thought my car was lugging at idle when I first got it.

Wait.








It has AC?

Yes. A Ford Explorer waiting in a parking lot yesterday was doing exactly the same.
Compressor would kick every 7-10 sec keeping the defroster going.
I thought it was weird because the V8 cycling sounded just like my boxer.

Hey, just wanted to pop in ask here instead of starting a new thread. I have my car tuned to OFT Stg2+ E85 and I also experience this same issue. I know the OFT is supposed to correct idle issues but I believe that may have been referencing it dipping and coming back. Is this normal for the OFT then as well?

Yes, totally normal.

It's normal.

How old is your battery? I ask because my rough idle smoothed out some when I replaced the garbage OEM battery. Mine used to stumble when I turned the headlights on, and the rough idle with A/C blowing was more pronounced when the lights were also on. After replacing the stock battery with an AGM, the extra stumble from putting a load on the alternator disappeared immediately.

My battery is about 4 months old so I don't think it's due to that. Haven't tested it though...

Then yours is probably just the normal weird idle.

Thanks, good to know its a feature not a bug haha

You can get this fixed with this TSB
https://www.ft86club.com/forums/atta...6&d=1386706237