My 04 6MT coupe has done great this winter, and never failed to start in down to - 25 F weather. However one thing does worry me : at any temp below 0, the car shakes upon starting. When the clutch is released in neutral, the RPM drops by about 500 and the shaking changes in frequency and intensity. This continues for a minute or two before the car warms up and everything's fine which I take as a sign to start driving.
It feels like the clutch is slightly dragging on a rough flywheel... Has anyone else experienced this and did it ever cause problems down the road?

 

Sounds like a misfire, how many miles are on your plugs, when was the last time you removed and inspected them.

The clutch release probably has nothing to do with the shaking probably, and YES it will increase load on the motor when you release the pedal with it in neutral. You are engaging the clutch and turning the input shaft of the clutch which then moves internal parts covered in extremely viscous gear oil which creates drag and drops the rpm's, you may even feel a slight sensation that the vehicle is "moving" when the fluid is very cold. This is normal behavior.

The vehicle shake increasing in intensity from releasing the clutch is probably due to a lower overall operating rpm when the clutch is engaged.

You may also be developing an intake manifold leak that's only present at very cold temperatures but goes away as the metal heats and expands, check torque on everything, check for tears in intake pipe boots.

 

The cold is killing my car! Just started my car to see the ABS and VDC lights were on, pulled the codes and got P1212 and U1001 which are communication errors... more electrical problems, great.

The PO said the spark plugs were 20k old but I don't know whether I believe him or not. I'll check those things over once it warms up a bit.... I hate winter.

 

Turns out the codes and warning lights are connected to my PO-installed CompuStar remote start/alarm. When the system is in valet mode, everything's fine. When the system is on and I try and drive the car, warning lights and the speedo doesn't work. Turn valet mode back on and start the car, everthing's fine again.

 

Sounds like it's electronics are being damaged from expansion/contraction due to weather. Time to uninstall.

 

Sounds like I need to turn the valet mode on before I start driving everyday... until things break more and my car won't start one day.