Hey! Thanks for the comprehensive response. From the paperwork, they provided:
- \"31-Point Inspection\" (all items checked off as okay except \"Engine\" which was marked as rough idle)
They spent about 45 minutes to an hour with the car and determined that the car was misfiring - that the intake valves were not fully seating when firing and that was causing the vibration. They performed a compression test on all cylinders to confirm no valve damage had already occurred. All four were 60lbs.
So, I approved their \"Major Tuneup\" work since they assured me it was the root cause. Work performed:
- \"Remove and replace timing belt\"
- \"Remove and replace timing belt tensioner pulley\"
- \"Tune Electronic Ignition\" (Timing Kit, Plug Wires, Rotor, Dist. Cap)
- \"4-Part Fuel System Service\" (Air filter, Vacuum Hoses, PCV, Fuel Additive) (Engine, Crankcase, and Throttle Body)
All this for the tidy little sum of $420 in labor and $394 in parts. Additional work performed at no charge was replacement of the waterpump which developed a leak the next day after servicing and the transmission mount after they took the car to a transmission shop who confirmed the transmission was okay. (I don\'t have confirmation on what they did to determine that)
UPDATE: In driving the car the last 2 days, I realized something new. The vibration is most severe when the car is cold. When you first start the car, after being outside in the cold, your eardrums buzz due to the low frequency of the vibration. It\'s not just the sound of the car\'s body parts and the dash items making noise, the entire car vibrates. It resonates during this time but once the car warms to operating temperature, it will idle a bit smoother/quieter - however, once on the gas to drive at speed, the vibration returns. Sitting at a stoplight, with car in park or neutral, you can rev the engine and feel the vibration return at all rpm levels, the resonance changes in severity at different rpms. Again, the vibration resonates through the entire car - to the point of making you feel as though the car has massage chairs for seats! :-) I literally feel the vibration in my spine through the driver\'s seat as I drive down the highway.
I\'m concerned about continuing to drive the car in this condition but equally concerned about the expense on this car. According to NADA, I\'ve already spent half of the car\'s trade-in value on repairs. Considering that I\'ve already had tires put on the car in the last year and just put in a new 5-year battery, I\'ve spent well over half the car\'s value in upkeep. I\'m stuck between throwing that money away and getting rid of the car and putting another several-hundred-dollars worth of effort to finally get it running right. (If that is even possible without replacing the engine)
I\'ve read several cases online of folks in this same situation, I just haven\'t seen conclusions that give me confidence I\'ve uncovered what is wrong with the car or that I ever will.
I appreciate everyone\'s thoughtful suggestions as I continue to ponder what to do here.