As the other posters suggested, make sure your thermostat is operating correctly (IMO - don't think that is the problem). If you can't flush the entire cooling system, then at least clean and gently flush radiator itself. The engine block drain plug on my b230f is near the bottom of the engine below cylinder #4. Maybe a book can help you find the it on the b23e.

Doubt it is the temp. compensation board, I think??? your car is a pre-temp. compensation board model.

How many miles/kilometers on your car? Is your radiator the original or does the radiator have high miles on it? My car has 232,000 miles and has the original radiator. The temp. gauge exhibits similar behavior to yours. After starting, the gauge goes up to about 3/4 then after a few minutes settles down to just above 1/2. I have flushed the entire cooling system and replaced water pump, thermostat and hoses. Also flushed cooling fins.

My guess is that your radiator, like mine, through age has lost some of its cooling capacity. I planning on replacing mine soon. You might consider having your radiator tested or replaced if it is as old as I think it might be. Not worth the risk of overheating and the damage that might cause....


Jim 90 244DL 232K