Did you bleed the cooling system? There's a bleed port on the head above the #1 intake runner. You're supposed to open the bleed port while you're filling with coolant so you don't trap air.
How do you associate coolant overflow with a leak?
I doubt the monovalve has any bearing on your overheating problem. All it does is regulate coolant flow to the heater core. Maybe W124 monovalves do more than W123 and W126 monovalves do.
86 300SDL (due soon)
81 300SD (for sale cheap)
Last edited by sixto; 03-25-2002 at 06:25 PM.