As you may know, I've been having some overheating issues. So far I've replaced the thermostat, radiator (broken) and viscous fan. The car still overheats, going way beyond the 100 degree mark in normal driving conditions and mild temperatures. My main suspect is a defective viscous fan (new Sachs unit). I never hear it and I thought it was normal until I drive a friend's E500 and I could clearly hear it.
Anyway, I haven't had the time yet to deal with it but in the meantime I thought a new radiator cap would not hurt. I went out for a short drive yesterday and when I came back I found that on the cap. Engine temperature was high but not crazy high, just over the 100 degree mark and auxiliary fans just kicked in.
Defective cap? Too much pressure in the system? Coolant too hot?
Thanks in advance for your help, as always.