I8ABMR

Hey guys I have noticed since getting my cooling fan recall work done that my idle will stay steady for 20 seconds and then jump by 100 rpm. It does this on and off but will do it most of the time. When I tun off the AC its more steady. I thought initially it was just the fans turning on and off but they wont do that every 10-20 seconds and it does it even when the fan is not on and the AC is running. I haven't noticed this before and was wondering if anyone had noticed the same thing wit their F. Sounds more obvious because of the rumble with the Joe Z exhaust . Thanks in advance guys.

I have an appointment to take her in this weekend right after I leave the track

2URGSE

Only a shot in the dark, but adjust the idle speed?

I8ABMR

I think it could be the air idle control valve because when I take video it does it every 12 seconds . Could be a vacuum leak causing the jump then the idle control brings it back down

I8ABMR

Here's a video

It's about a 150 rpm jump every 12-14 seconds only with AC on. It's very steady with it off

2URGSE

Vacuum leaks can cause all sorts of issues.

I8ABMR

Since it seems like I am on my own on this one, I will update for the next persons future reference.

The situation happens when the car is warm , the AC is on Auto with the setting on recycle. If it goes to fresh it seems to decrease and when the AC is off the idle goes smooth. Also heard a creaking noise from the left side of the motor and a hissing sound from near the radiator the noise lines up with the variance in rpm. I think its a vacuum leak. Not sure . Considering I have a track day coming up I'm taking her in ASAP.

I'll update as to what the issue was when I find out. Thanks for your help URGSE

Vervish

iTrader: (4)

+1 for vacuum leak.

2URGSE

Sorry I couldn't offer more help. I can phone my good friend Patrick back in California and ask, he may have some suggestions. (Toyota Master Mechanic)

kauaian

iTrader: (18)

Did you check your AOS hoses?

j3ff

Could it be your a/c compressor engaging? Not sure if you can hear it in the engine bay but perhaps the compressor clutch is not engaging properly. Awhile back I had a corolla that had similar symptoms.

If not, I'd also go with vacuum leak. Let us know!

I8ABMR

Thanks so much for the support and help guys. I set an appt for tomorrow . I am hoping they can get it fixed quickly. I am signed up for a Summer Track addicts Track day this Saturday and will be heart broken if I miss it. Next one isn't until Halloween weekend.

Again , thanks for the responses guys.

2URGSE

Hopefully your mechanics are better than SoulFreak's mechanics, otherwise there is no hope for humanity.

I8ABMR

What happened ?

Meanstreak

I had a vacuum line break when I took my car in for ELF recall. The SA said it was a brittle hose. They caught it, corrected and notified me before I picked it up so I don't know the exact symptoms but certainly something that should be checked. Good luck.

I8ABMR

Thanks for the heads up buddy. I am hoping they can just get it sorted quickly and without charging me up the rear. I just want her all ready to go for Saturdays track day