Hey all,

I know similar topics have come up like this, however, I have not been able to find one that matches my situation.

Since Wednesday of this week, My engine has been idling rough in gear when warm and when the A/C is being used. While driving, my 4runner is fine, when I stop the idle hangs around 500rpm. Troubleshooting this since then, I found out when driving without the A/C on, the car will idle a bit higher and wont be rough. Also since Wednesday, when driving around with A/C on when stopped, I hear this loud beeb or whine. I found out its coming from the A/C and stops when I turn the compressor off. Could my compressor be dieing, low on freon or a belt be going out?

I am also going to replace and clean stuff related to this (clean MFAS, TB, replace air filter, plugs, wires, ect).

Please let me know what you guys think, my specs are below.

1990 4runner stock
3vz 3.0L

 

Sounds like the bearings might be on their way out, creating extra drag. There is also an idle up vsv which bumps the idle up when ac is running, check that out.

 

this is what it looks like on a 22re... its all I got...

 

Have good news, I cleaned the Mass Air Flow Sensor, Throttle Body, changed air filter to a K&N and raised the idle. My yota is running better in idle with air on and off. However, that loud beeb/whine still present and I can only hear it while in gear.

After troubleshooting the issue as best I could, I brought it to the dealer and they confirmed my A/C was working normally and the sound I hear could be some debris in the vent.