FluKy15

OK that makes much more sense

Car Analogy

So it vibrates even at a stop, right? If engine running, it vibrates, rolling or not, yes?

So as was mentioned it could be motor OR trans mounts. Obviously can't be diff mounts or other drivetrain issues (can't be wheel balance, driveshaft, hubs, etc).

No power loss so not likely a misfire (if misfire bad enough to cause vibrations described you'd expect loss of power or a cel or both.)

What about engine accessories? Serpintine belt driven, AC condensor, water pump, idler pully, tensioner? Try removing belt from tensioner, and start motor for a few sec. Should be able to rule out accessories with about 15 min of work.

C63AMG

Symptoms

• Vibration worse at idle than under load. (Under load the motor has more vibration isolation)
• Vibration unchanged when clutch pedal is depressed. (Rules out drive line and clutch disc)
• Vibration amplitude and frequency increases with rpm. (Something rotating causing an unbalance)
• Decreased fuel mileage. (Bad motor mount "shouldn't" cause this)
• No non pending DTC.

They symptoms don't really add up but if they're accurate, it points to something mechanical that's rotating and affecting the efficiency of the engine.

Billman250

I've seen many broken motor mounts, they never caused vibration.

Does anything change with the car in first gear, not moving, clutch in? (this takes the trans input shaft and disc out of the equation)

Slowcrash_101

This is tricky to diagnose, it could be a lot of things, could be valve adjustment related, the crank pully. Could be something silly like a bad PCV valve, or sputtering fuel injectors that flow normally under load but dribble gas at idle, could be MAP related or a clogged throttle body, or dirty IAC valve, it might be a combination of things.

vstypicals

Updates? I think we have the same issue. Unfortunately, I have been busy and haven't had the time to get a second opinion on mine.
https://www.s2ki.com/s2000/topic/107...a-certain-rpm/

zeroptzero

I believe Mike resolved it by replacing his transmission.

vstypicals

Crazy.. My shop said it was the motor.
Thanks!