2002 Camry Rough Idle when ac on and warmed up

So guys, I have a 2002 camry 2AZ-FE 4 cylinder 4 speed auto. Lowish miles(48k) but it idles roung when it warms up and the ac is on.

If I remember correctly, alldata states normal idle is 750rpm or so +- 50rpm. I find that when hot, the idle when at a full stop goes down to around 600 and the car shakes pretty bad. I can feel it through the seats, the steering wheel, the car just shakes realyl bad like an old diesel.

The car shakes and goes down to 600rpm no matter if the ac is turned on from level 1 to 4. Turning up the ac dosent seem to change the shaking or lower the idle even more. Furthermore, turning off the ac creates a good 750rpm idle.

Power seems good, but then I've had this problem since i've ownned it so im not sure how it should feel new. Minimal (fractions of a fraction of a second) throttle lag, good power it seems to me and good mileage. The car checked out fine the lat time I scanned it for codes. No check engine light.

Shifting to neutral gets rid of the shaking pretty much but I'm not sure what can be causing this. Any ideas?

I'd start by cleaning the throttle body, bore, and plates with some O2 safe carb cleaner and a toothbrush.

With the engine at operating temperature:
At what rpm does the car idle when the car is stopped in gear with the A/C off?
At what rpm does the car idle when the car is stopped in neutral with the A/C on?

With the engine at operating temperature:
At what rpm does the car idle when the car is stopped in gear with the A/C off?
At what rpm does the car idle when the car is stopped in neutral with the A/C on?

1. ~750rpm
2. ~600

I though about carbon buildup possibly holding the egr valve open partuially during idle. It would make sense since it seems to happen more pronounced when I drive with more thottle opening., but then why would the shanng dissapear when I turn off ac?

mwmorph, I dont want to alarm you but it might have to do with your AC compressor. Sometimes they do not work smoothly and the car has to do more work in order for the compressor to work. I would recommend starting with something simple, like takind an 8 1/2 oz bottle of AC oil lubricant and having the entire bottle pumped in your system. It will reduce your compressor noise and hopefully help with the idle problem too. I was having a similar problem and the procedure mentioned above helped me. I hope it helps you too.

did you ever found what was the cause of the problem and the fix?
Have the same problem with Camry 2003 56K

There is an idle-up adjustment valve or an input to the ECM to adjust the IAC idle valve usually for cars equipped with A/C to compensate for the extra load on the engine when running the compressor at idle. If that does not work properly, the idle will drop below normal and cause the rough idling. The other possibility has already been mentioned: a bad compressor that is starting to seize. If it is a bad compressor however, that is usually accompanied by noise. You would have to break out the manual for your camry year to see how this mechanism is implemented and the appropriate diagnostic tests for it.

dave mc

Hello, I just saw your posting as I recently had the A/C relay on my 02 Camry 4Cyl LE replaced due to the flashing light symptom. The dealer told me they replaced it with a new part- the older one is no longer made. However I have the same issues as you. Now, whole car shakes when the A/C is on and the engine is idling. The dealer says the part is the suggested replacement, but I find it hard to accept since the car now idles really rough. I suspect you if you bought the car used, yours may have had this relay replaced. I would suggest replacing the relay, or doing as the last poster mentioned with the ECM or Idle adjustment valve.