My Toyota Camry seems to idle rough when I come to a stop (i.e., at a traffic light). If I move automatic transmission to neutral, idle is not rough any longer. When I go back to drive, engine speed increases and seems rough.
I suggest having the Idle Air Control valve cleaned or replaced.
This assumes all other maintenance is up to date.
I agree–as I usually do–with mcparadise.
If the car has not been maintained properly, that is the place to begin. The symptoms that you describe could be the result of spark plugs that need to be replaced, or the result of a dirty IAC valve, or even the result of bad motor mounts.
However, bringing the car up to date with maintenance is definitely the way to start solving the problem. If replacing old spark plugs and air filter do not help, then you can delve further into the problem.
I’ve had a 1995 Camry wagon since 2003. I’ve had the ignition coil replaced 3 times. (I was assured this last time by my trusted mechanic that he used a genuine Toyota coil.) My thought is your coil could be getting close. The rough idle is from the engine being under load. I agree with the other replies regarding the general tune-up steps. Once those are done and it’s still rough, you may want to have the coil replaced. I only got some warning (some hesitation and rough running) the first time it failed. If I ever get any warning like that again, I will have it replaced immediately because when it goes, it goes completely and you car is dead.
The car is running fine otherwise, my vote is for motor mount(s) that need replacing. If the roughness is even and always the same it’s probably your mounts. If it were an unsteadiness (rpm fluctuation, near stalling, lack of power, hard starting) it could be something else.
Took the car into Pickering’s in Midland, MI (which I was very pleased with) and turns out the air control valve needed to be cleaned and adjusted plus passenger side motor mount needs to be replaced. The front engine had already been replaced by another shop.
Thanks to all who responded. Running very smooth now.