2strokecoldsmoke

So I went and changed the coolant in my new M5 last night.
(I still need to post pics of it now that it is home, but that is another topic )

I had no problems with the draining of the coolant - remove radiator plug, got about 1 gallon, removed right side block drain, just over a gallon came out, removed left side block drain, got about a quart.

I then followed my normal cooling fill procedure of lifting the front of the car as far up in the air as possible, which allows air bubbles to migrate to the front of the system, which is of course where the openings are. No bleed screw visible anywhere in the system. I popped the upper radiator hose off during the fill, as it looked like air could get trapped in the there, and stuck it back on after coolant started coming out.

As I had captured almost all the coolant that came out, I measured it and found that I had about 9 quarts. I put damn near exactly the same amount of BMW coolant (60/40 mix, distilled water, of course) back in.

Sooooooo
I got on M5Board (well, first I ) to double check the capacity and see if it seemed normal to still have 2-3 quarts left in the system after the drain. Seems normal to me, as can't drain heater core, etc.
And I find several posts that detail a "highly involved TIS procedure for bleeding the cooling system" and "getting air pockets in the heads".

Well, I put in exactly the amount that came out. I don't see where air could have gotten trapped anywhere.
What are the TIS procedures, and did I do anything wrong here?

thanks!

DouglasABaker

The bleed procedure is basically to fill the system and the overflow, run it until warm (thermostat open), let it cool, and fill the overflow tank again.

Repeat until overflow tank level doesn't change.

d-

2strokecoldsmoke

Well, that sounds easy enough!

So what's with these "highly involved TIS bleed procedures"?

Still can't believe how easy the coolant draining was, on most cars the block drain plugs are a real $!@& to get too.

DouglasABaker

I gave you the summary - I'll give you the real TIS if I can find my disc again. Might want to shoot me a PM reminder

d-

2strokecoldsmoke

Thanks!
reason I asked was I had found a thread where someone was saying that the S62 was prone to getting air bubbles trapped in the head, you will cook your motor if you change your own coolant, etc, etc.

But, on all multitude of different liquid cooled engines I've worked on, I've never seen any thing that ran that sort of risk of not getting the cooling system bled that didn't have a bleed screw at the system high point. So I was a bit skeptical about the information provided.

Anyways, unless someone can provide compelling evidence to the contrary, I'm going to proceed as normal with this coolant operation.

DouglasABaker

Here's the TIS - I forgot the part where you need to turn the heater on high.

d-

Attached Files

Coolant System Purge.pdf (45.3 KB, 530 views)

2strokecoldsmoke

Thanks Douglas!

Well, I'm going to write off the old posts on this board that are talking about 'highly complicated bleed procedures'.
Now that I've seen the TIS, there is nothing special here, except having the blower on low.

I idled the beast to almost operating temp after filling the system. I turned the heater on high (that is normal procedure for any car) but I did not have the blower on low. I will do that tonight, as I have not yet driven it yet. But so far, no change in coolant level in tank.
I think that raising the front end up during initial fill helps get air out of the system.