Feedback on coolant flush techniques? - The Unofficial BMW M5 Messageboard (m5board.com)

PRAXXUS · 9th January 2007, 02:36

It's that time of year to prep for changing fluids. Specifically coolant system (antifreeze). What is your thoughts on doing it the traditional way, use drain plug on rad and on engine block near cylinder #6, and then fill with fresh fluid; http://www.bmwe34.net/E34main/Mainte...eplacement.htm

OR

what most of the garages want to do is hook up some sort of coolant flush system, and "push" the old coolant out while replacing with the fresh coolant.

Should I stick to the traditional way or can I use the newer process most mechanics want to use??

Are there any pros/cons?

BTW, it has been recommend to use ONLY BMW coolant fluid, as the others are not as good - opinions?

TIA

farrell · 9th January 2007, 11:10

Hi
Changing the coolant every two yrs or 36,000 miles is a smart move.
Conventional coolant change is all that is required...unless the car in question has cloudy deposits in the coolant.
First point is to use distilled water.
1. Tap water is bad for coolant systems due to the lime scale & Aluminium /
magnesium hydroxide traces sometimes present.
The presence of organic / inorganic mineral accelerates furring of the
coolant system actually reduces main & auxilliary water pump bearing life.
2. With distilled water, the absolute boiling point of the coolant is more stable
with the above removed.
If your existing coolant is cloudy, I would replace coolant & run the engine to get the coolant up to to temp ensuring no air leaks, then drop the coolant again.
Replace with new 50/50 distilled water & coolant that meets the BMW recommended spec.
You dont have to use BMW coolant unless of course, you like setting fire to $$$

I hope this helps.

Farrell

dronfieldm · 9th January 2007, 13:49

I watched a BMW Technician do mine a couple of years ago. From what I could tell, he took the filler cap off, undid (slightly) the drain plug on the radiator, and ran the engine at idle, constantly topping up the tank with new coolant until it came out the radiator drain..........

Obviously he could have done other bits I didn't see, like uncrewing other bleed valves etc, but thats essentially what he did.

No trouble since...........

Mark

davidoli · 9th January 2007, 13:51

Quote:

Originally Posted by farrell

David
The original thread starter title was in "CAPS"

Farrell

Cheers Faz........I looked at it after the request .....then looked at the one next to it .....with RATTLE RATTLE in the title and wondered what the hell was going on !

Hope you are well.....D

unesential · 9th January 2007, 14:35

If the system has been properly maintaine d a routine Biannual drain and fill should be good enough. If the system has had problems and continuosly topped with tap water then a power flush with a descaler would remove some build up that occurred. Most owners of these cars are aware of the coolant system importance and also tend to keep things up to snuff so as Farrel stated you could determine the benefit by simply looking at what you remove.

PRAXXUS · 9th January 2007, 23:57

My concern, is how the coolant is removed from the engine. There is of course the traditional method (using drain plugs), but most garages now use a method whereby they connect a machine (some sort of T-connector) and "push" out the old and replace with new coolant at the same time. My concern is how this machine does it, and how effective is it and "flushing" the system. Should I focus on using a garage that will drain and or flush the traditional way, or is it safe to use the new system.

Also re: CAPS, I apologies. I was under the assumption that it is an acceptable practice in Title.