overheating and no heat at idle.

[C.Doner]

This is the 82 300d euro. I believe no secondary water pump I believe. Manual Heat and air. No A/C .I am thinking its a worn water pump. At idle the cabin blower will go cold and the engine will heat up fast. If I leave it idle for 10 or 15 minutes it will be above 100 and climbing. I give it a rev and it drops back quickly. No issues at full power on hills or in the summer heat.