@Ian1892 check coolant if it's low could be a problem ,if you go to dealer probably cost more than you paid for the car lol also thermostat could be bad.
@Gangstress I've only once driven a Merc. Had a go on someone's old E class. Felt it clunky round town like trying to manoeuvre a cruise liner instead of a speed boat. But when I got onto the motorway I could really see the point 😆 Said to owner, "it's really good fun when you get past 90, isn't it?" 😆👏🤗
depend on which generation you own,if the first two w168 and w169 you can diy replace the themostat with some simple tools like plier and screw driver and some wrench box set.But any later generation like w176,w177 after is impossible you can do it your own,the shit thing locate underneath battery,throttle body and intake manifold,you need disconnect a hell lot of hose and wire and take out these part before then.You also need to bleed the system and reprogram car computer afterward.
@Ian1892 turn your engine off. look under the hood, follow your upper rad hose. Should be 2 bolts of some sort where it goes into the block. Undo those, pop the old thermostat out, put the new one in and put it back together. Don't know how simple that is on a Mercedes, anything 20 years or newer seems to have at least one plastic cover to remove
