Cold Temp, R16 resistor, High RPM – HELP!
Check out this madness. I have a 1990 300E with the following symptoms:
1) Temp gauge reads slightly over 40…all the time (in traffic with AC in Georgia!). Well actually not all the time. Every now and again it will actually read the correct temp.
2) Intermittently, upon start up of a *warm* engine, the RPM will zoom up and idle at 1800-2000. After maybe 40 seconds, it drops down to the normal 750 or so.
3) When I remove the R16 resistor and start up after the engine is warm, it will rise to 1800-2000 and STAY there. I have to turn off car, reinstall resistor, and restart car at which time it will do what I described above.
Here is a totally make up theory of mine. As I understand it, when the car is cold it raises the RPM to help with the start up. So now, because of a bad temp sensor somewhere, the car perpetually thinks it's running colder than it is. Thus the low gauge reading and high RPM.
I have no idea what the relationship is between the RPM problem and the R16 resistor…if there even is a relationship. Unless I am totally confused, the R16 resistor advances the engine so by removing it I am retarding it back to 0 degrees.
Does this make any sense or am I on drugs?