Engine shaking
 

Can you please provide me with some insights into areas to explore or the possible root of the problem based on the below. I have a 2004 Camry LE.

If I am in drive (with the breaks on. I.e. at a stop light) and I have the fan and AC on, the car starts to shake. I checked and the engine was shaking. Not too hard but very noticeable to be checked out. If the fan is on without the compressor on then things are okay. Actually If the AC is on and I am in park things seem to be okay from what I could see. The AC is giving cold air. Also maybe I don't notice it when driving, but things seem okay when driving with the AC/Fan on/

I can carry out some tests and report back if anyone has some thoughts.

Thanks.

The increased electrical (from brake light, fan, etc) and mechanical load (from A/C compressor) may be causing the idle RPM to drop to low. When it drops the engine shakes at the lower RPM by engine design. Meaning lower RPM typically results in more engine shake.

Determine what the RPM has dropped to when shaking.

If idle RPM OK could be bad engine mounts.

Research on cleaning the throttle body. The throttle is electric and idle RPM controlled by computer.

Hi, thank you toyomoha. Yes the RPM drops a bit when the compressor starts up. Thank you for that tidbit of info. Actually, it may be more of the Air filter housing shaking but that could be a result of the engine. I'll look at the mountings next. I may post an update so could use some more help in the future if you don't mind.

Just an update. I cleaned the Throttle body. After cleaning it, the RPMs at idle was much higher. I then reset the timing and it looks like I have the idle RPM at the correct value with the AC on (I.e. 700 RPM). Thanks.

Great job!

Thanks for posting back with the fix.