Filling radiator/block
 

(1982 300CD Turbo Federal)

I'm doing a coolant change/flush, and after removing the old coolant (yellow stuff, looked pretty good) I closed both plugs (radiator and block) and filled the radiator from the expansion tank. After turning the car on and driving around the neighborhood, the car heated up EXTREMELY quickly, reaching operating temp in about 120 seconds and then continuing to climb- I shut it off before it got over 100 deg. C, but the needle was moving, visibly, quite quickly.


I've looked through older threads and seen references to filling the radiator first using the upper IP-side hose and then using the expansion tank- I did not do this. Could this be the reason why the engine tried to overheat almost immediately, or is it a burping (which I've never been able to do successfully) issue of some sort?

Thanks to anyone who can give me a lead...

Sounds like your car needs a burp!

The FSM recommends (for the purpose of filling with coolant) running the engine intermittently with the heater on and expansion bottle cap not installed.

In my experience, the process is sped up a bit if you remove the upper hose from the radiator (engine not running) and hold it vertically while adding coolant to the hose.

She just needed a burp, which she got.

I've actually found the block draining process to be much less difficult than advertised- the trick seems to be to press the socket and extension on to the bolt first, and then attach the wrench to the extension.