anyone know the average engine temp reading on the dash gauge for a 1992 500SL...mine runs above the white dash after the 80 dash.... I think it is the 100 mark. Soit runs around 110..it has a C for celcius....so is 110 or so Celcius..waht is that in Farenheit and is it okay for a hot town like Las Vegas ?

Your thermostat should be set at *about* 85 C. Fans should kick on at 100 C. When idling in traffic or in hot weather, 110 is still OK for your engine. Anything higher and I might worry a little.
But if you do a search on engine/coolant temps... you will find a wide range of info on this matter...

My 95 can run up to the 100 mark on a warm evening in Texas. Consider that the engine compartment is pretty tight in there, so heat dissipation is not optimal. IN that regard, I would suspect that the 300SL probably runs a bit cooler...

That should be the M119 engine which is also in the 500E but with a different fuel injection system.

These are known to run "hot", especially in the W124 chassis 500E/E500.

Run a search (upper right) under "500E hot" and you should find plenty of info.