you say you cleaned the radiator... do you mean you took it out and physically pressurewashed it from the fan side to clear ALL the debris from it? cause if you didn't, you did not clean it well enough. also after you have pressurewashed it for debris, you need to soak it in some good bug dissolving detergent and rinse well.

next be sure you acid flush the entire cooling system. with some good rinses in between... follow the procedure described here. be sure and degrease well first, and rinse well after the degrease from the block drain twice at least...
next verify you have a NEW GERMAN 76°C thermostat. NEXT verify your water pump impeller has not disintegrated...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!