At a stop light, clutch out, brake in, car in neutral.

Car seems to idle a tad bit rough, and it will come in waves. RPM's stay at about 700-900. About 500 miles on the engine. Is this just bad gas, or something MT's do?

And yes I am paranoid about breaking my car. ;)

Thx

 

usually the car will vary the idle rpms for the first 3-4 minutes that the car is turned on. At least for me. I'm not sure why it does this but if the car sits for over 12 hours i can usually start the car and release the clutch and it will accelerate slightly by itself.

 

Could be....

It felt different when I was using 91? Super Unleaded octane... I can feel that it vibrates differently as if something isn't firing correctly.

So I using 89 now...

 

My tC does feel like it runs a bit rough, but so did my camry with the same 4-banger engine since new. I guess it's a toyota thing because my little Nissan truck idles super-smooth.

 

when it's cold the tC engine runs a 1-3 cylinders and 2-4 cylinder firing pattern.. so it's going to be a little rough.. it's only for quickly warming the engine up (and less emissions) but when it warms up it goes back to the 1-3-2-4 cylinder firing pattern. and smoothes out..

Mine is running smooth (rough when cold, but that's only the physics of the cold-engine program running with the 1-3 and 2-4 cylinders)..