Thanks a lot for great diagram Myarmar I bought this car with tons of problems and overheating is one of them. What you said made picture complete because I noticed overheat only when you drive the car and owner bought it at auction and he said he ran the car on idle and it never overheated but he never drove it. So when rpms go up and temperature rises most of the coolant bypass back into the engine causing overheat because there was no thermostat when I opened its case. I will install one and report back.

Thanks

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1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod