Anyone know of a coolant flush how-to ?

The Bentley is a bit lacking and I would like to try and do a complete flush.

 

I just followed the bentley directions, disconnecting the lower radiator hose, draining, and running water thru for a while to flush everything. Apparently there doesn't seem to be a separate plug for the engine block like some BMW's have, but i may be wrong. After running fresh water through for a little while, i let it drain thoroughly, reattached the radiator hose, then refilled with 50/50 BMW coolant and distilled water. Pretty straight-forward.

 

There is a block drain, but it is behind the starter and not worth getting to. When doing the flush, it helps to remove the thermostat, so you get water moving through the block. This is a good time to replace it. Filling from the expansion tank takes forever and does not purge enough air from the engine. Ideally, you want to refill using an airlift tool, but since most people don't have one laying around, take the upper hose off from the bleeder fitting, with the cap off the expansion tank, pour the coolant directly into the radiator. This will get you close. Then, top off the tank, and remove the bleed screw until all the air comes out. Do not overtighten the plastic bleed screw and be careful not to lose the rubber o-ring, it will usually stick the the opening. Also, since there will still be water in the block, pour in about a half gallon of unmixed coolant first to compensate, then mix the rest, should take almost 2 galllons. Let the car idle with the cap OFF for about 15-20 minutes, top off as needed, but keep the level at the ridge. If you overfill, it will just boil out. Watch the temp gauge, and put the cap on when its fully warm. Let it cool down and double check the level cold.
I prefer to use the factory coolant in my shop, but the Prestone long life or Zerez G-05 (NOT Dex-cool) should be fine. No Phosphates and low Silicates is what to look for.
--Dan

 

One more note... I have had a lot of cars towed to me after the owners attepted servicing their own cooling systems. Its never good and usually costly if the engine overheats. If a shops screws up your car, they should have insurance to cover it, but if you do it yourself... Well, you get the point. Not trying to be a downer, just be careful. Cheers.