You are at risk of spending a lot of time and possibly money uneccesarily. As I suggested ...
You are at risk of spending a lot of time and possibly money uneccesarily. As I suggested in my reply to your other post, your car has all the symptoms of a the ECU not operating. A common cause of this fault is a blown fuse on the overvoltage protection relay or the relay itself. You must check that the ECU is receiving power before continuing trying to rectify the faults you describe. If loading the engine (eg. in gear, full steering lock, air-con on) cause the idle speed to drop, then it is a fair bet that the ECU is not operating. Some years ago, I purchased a used '92 180E (low cost version of the 190E 1.8 here in Aus). It had the same symptoms you describe, difficult cold starting followed by lean running until warm, high idle speed etc. A new fuse in the OVP relay and it was an entirely different car. Coincidently, it had a new battery. The blown fuse may have resulted from jump starting due to a flat battery prior to my purchase. It is interesting you mention yours recently had the alternator and battery replaced. Please check the OVP fuse before you do anything else.
Regarding the "overheating" it is quite normal for the temperature to rise to just over 100 in traffic. The coolant thermostat only begins to open once the temperature is well over 80. At 100 the fan clutch engages so at temperatures below this only movement of the car pushes air through the radiator. Obviously in traffic due to lack of air flow, the temperature will rise until the fan clutch engages. If the temperature continues to rise beyond this the electric auxiliary fan will switch on. Many people are alarmed by so called overheating in MBs, but temperatures from about 85 to over 100 are normal. Only if it gets over 110 should you start to get concerned. Boiling will not occur until over 120.
You are at risk of spending a lot of time and possibly money uneccesarily. As I suggested in my reply to your other post, your car has all the symptoms of a the ECU not operating. A common cause of this fault is a blown fuse on the overvoltage protection relay or the relay itself. You must check that the ECU is receiving power before continuing trying to rectify the faults you describe. If loading the engine (eg. in gear, full steering lock, air-con on) cause the idle speed to drop, then it is a fair bet that the ECU is not operating. Some years ago, I purchased a used '92 180E (low cost version of the 190E 1.8 here in Aus). It had the same symptoms you describe, difficult cold starting followed by lean running until warm, high idle speed etc. A new fuse in the OVP relay and it was an entirely different car. Coincidently, it had a new battery. The blown fuse may have resulted from jump starting due to a flat battery prior to my purchase. It is interesting you mention yours recently had the alternator and battery replaced. Please check the OVP fuse before you do anything else.
Regarding the "overheating" it is quite normal for the temperature to rise to just over 100 in traffic. The coolant thermostat only begins to open once the temperature is well over 80. At 100 the fan clutch engages so at temperatures below this only movement of the car pushes air through the radiator. Obviously in traffic due to lack of air flow, the temperature will rise until the fan clutch engages. If the temperature continues to rise beyond this the electric auxiliary fan will switch on. Many people are alarmed by so called overheating in MBs, but temperatures from about 85 to over 100 are normal. Only if it gets over 110 should you start to get concerned. Boiling will not occur until over 120.
