Originally Posted by Jooseppi Luna

Now that it's been getting colder here in New England, I've noticed a somewhat unsettling behavior in the Corolla: clutch chatter. When the car is cold and I am engaging first (or second from an abnormally low speed), the clutch makes a chattering noise and shakes the whole car. After confirming that I was nowhere near stalling, I figured that it must be clutch chatter because it felt like something I would call clutch chatter. I researched it a bit and found an ASE page on clutch chatter. They listed the following as possible causes:

• Worn flywheel
• Worn clutch
• Leaking crankshaft main seal or transmission front seal
• Bad pilot bearing
• Pressure plate wear

I'm trying to guess as to which one of these it may be. I think one of the main clues is that it only happens when cold, but I'm not quite sure what it means . The car doesn't use oil to my knowledge (though I will be watching that more carefully), so I doubt it's the crankshaft main seal, and I'm dubious on the pilot bearing, because I'm not seeing any other pilot bearing failure symptoms -- although the car does squeak when putting in the clutch. The clutch does not slip even when I floor it in 5th @35 MPH (GRUNT GRunt grunt).

It seems to me that if it was a fluid leak, the behavior would not be tied to the outside temperature. My money at this point is on the flywheel or clutch (I learned to drive in this car, so the clutch got some major abuse around 132,000... it is now @ 150,000), but what do you guys think? Why would the chatter only happen when it is cold out? It happens with an ambient temperature of 50 in the morning (the previous night had been in the 40s), but at 60 in the afternoon you have to really concentrate to notice it.