85 380SE thermostat question
 

just bought an 85 380SE that gets a little warmer than i think it should before
the t-stat opens (like in the 110 level) :eek: so i plan to flush and switch out the t-stat. problem is the t-stat i was given appears to be one for an '86 420SEL -- doesn't have all the extra "wings" and brass parts to it that the one on the fastlane picture does. plus the correct one on fastlane is apparently an 84 deg. t-stat and the one i've been given is 80. it's a wahler t-stat.

my question: are these compatible, or am i in for trouble? (trying to save an
hour's round trip on the return.)

All MB thermostats have a flat valve plate on the back. It it looks like a thermostat out of a Ford, it's the wrong one. This plate closes off the recirculation passage around the engine, forcing the coolant out into the radiator. If it isn't there, the coolant mostly just goes round the engine. Fine for warmup, but it gets pretty hot if you need cooling!

You should have an 85 degree thermostat, and I would get one from FastLane or the dealer, they aren't that expensive and you really do need the correct one. Wahler makes all sorts of thermostats, you could easily have the wrong one. 80C is too cold, you would run in open loop too much, eating gas.

Peter

thanks, peter.

should have gone to fastlane in the first place (yeah, i knew better! sometimes the shortcut isn't so short.) got a shopping list of doodads
to get anyway.