Dear Tom and Ray:

I have a 1980 Chrysler New Yorker Fifth Avenue that is my favorite old car (after a Nash and DeSoto that I drive on weekends). Don't laugh, many people consider the 1979-81 big Chryslers to be among the best looking styles of that era. And since only 389 of my particular model were manufactured, they will likely become collectible one day. Anyway, it has a problem that just doesn't want to go away. The engine vibrates at all speeds, most obviously at 1,400 rpm, to the point of shaking spark plugs loose. It's not a misfire, and the engine does not noticably shake. I have replaced the EGR system, all three motor mounts, and the spark plugs and plug wires. The carburetor has been adjusted and readjusted. I have run cleaner through the combustion chamber, and flushed the cooling system and the oil lines. The vibration is still there. I have checked out the electrical system, vacuum lines, fuel, and emissions control system, and they all appear to be in good shape. The car passes the California emmissions tests with better readings than some new cars. The dealer says it might be the catalytic converter. Might it be? Don't tell me to get rid of this car. I plan to keep it no matter what happens.
Richard

TOM: Well, we won't comment on the fact that you've developed an unnatural attraction to a car that has very few redeeming characteristics, Richard. After all, "De Gustibus Non Disputandam Est," which is latin for "Hey, if you like it...it's none of my business."

RAY: You've been pretty thorough in your investigation of this problem, and you've obviously spent a lot of money replacing parts, for which I'm sure your mechanic is grateful. But I wouldn't replace the catalytic converter just yet.

TOM: Right. The fact that the car passes the emissions test eliminates a lot of things. Not only does it tell you that the catalytic converter is fine, but it also tells you that the valves or rings inside the engine are OK, too.

RAY: So my next inclination would be to check the harmonic balancer (aka vibration damper). That's a cushioned pulley that's bolted to the front of the crankshaft that, when it's working correctly, keeps the normal crankshaft vibrations from spreading to the rest of the drive train. That could certainly cause the problem you describe. And more importantly, it's cheap!

TOM: And if that's not it, then you may be looking at a more expensive problem, like a worn out thrust bearing or a bad torque converter in the transmission. You're not going to like the costs of those.

RAY: But you say you're in this for the long haul, right Richard? So muster up your courage, haul this baby down to your mechanic, and pray hard for a bad harmonic balancer.