Radiator Flush advice from BMW Mechanic
 

Just got off the phone from the Toronto BMW Dealerships Service Division, I called in and told the service rep that I'm planning on doing a radiator flush this week-end myself and asked if had anyadvice on it..he called in the Technician from the shop and put him on the phone, I posed my question about draing the Rad from the plug and Engine Drain plug, he don't need to do that way, heres his steps:

• Open Rad fill knob and bleeder screw
• Put hose from bleeder hole to bucket for filling old coolant
• turn on car put fan on and heat on
• the bleeder hole will start dumping out fluid into bucket while that's happening
• put fresh mixed fluid in (50/50) through Rad Cap
• Do untill you finish filling in how much you wanna change, the 3.0 will take around 7 litres mixed so a 4 litre tub from stealers mixed with water 50/50 would be good enough.
• This method will ensure all old fluid comes out as you fill in new fluid and that there is No Air in the system when your done.

He said the flush should be done every 4 years.

So what do you guys think?

faster to just drain and then fill. Takes 15 mins. That way will take forever

I haven't heard of that way either, but I guess it would work... I say the drain and fill "normal" method is the way to go.

Do you guys just drain from the Rad Plug, then fill or Drain from Rad plug and Engine Drain and then Fill also how about the air how do not make sure there is no air.

I'm finding it hard to find the engine drain plug...so many sources have different ideas and locations...waiting for my Bentley Manual still so can't pin point it.

I do the radiator drain plug and the block drain plug. (which is on the passengers side of the block, between the ac compressor and motor mount. 13mm bolt head)

To fill have the bleed screw still out and pour the 50/50 mix in slowly untill coolant comes steadily out of the bleeder screw as well as the radiator cap. Close off the bleeder screw then start her up. Have someone hold the rpm's about 3000 and you should see a solid stream of coolant pissing across the radiator cap opening. If that stream is strong and steady then put the cap on, you are done.

Hey Weasel, thanks man,,,gonna sound stupid but do you have a pic of the Block drain plug or what angel to approach it I assume from the bottom but some have said take the front right wheel off and then turn the wheel all the way left to access it..,,,scared I may open some other "Portal to hell"

Also you say pour slowly until coolant comes out of bleeder screw and radiator cap (do you mean Expansion tank) ...aren't you filling through the expansion tank or Bleeder hole? or are there 3 caps to open 1.Bleeder hole, 2. Expansion Tank Cap, 3. Radiator Cap...?