Today, my car made a violent bucking sound on start up...
 

So today was the coldest day of the year (so far) and when I went to start the car up, it made this pretty loud bucking sound + vibration form the engine - like a bull trying to toss the rider. Obviously the RPM dropped a couple hundred with each "buck" (no this is not the RPM issue this car has been known for). I drove it home fine afterwards with no problem but am wondering if this is something I should be worried about. Or is this something that happens when its really cold outside? I also had my fan on "1" when I had initially started up the car - I have noticed the engine makes a slightly more violent start up noise when you start it up with the fan on.

Oh, I reckon your car is OK ..... it just doesn't like to get up on cold mornings.

I understand that the ECU starts it off with some "settings" than the engine itself may not much like, but, is better for emmisions compliance.

As long as it settles down soon after start up and doesn't get crankier , I wouldn't worry about it.


humfrz

On cold mornings I turn the the ignition to ON then wait 2-3 seconds for the fuel pump to prime the system. Even with that i get a slight buck and popping. It's running way rich so it's normal.

Mine makes a loud rev sound right away when temps under 33℉ and mini pops Have TRD exhaust.