Z4M Coolant Change

Kern47

Member
I've had a quick browse, but cant find anything recent/specific...

I've decided I'm going to change the coolant as mine seems to be erring on the low side. I rang BMW up and they didnt fill me with confidence when they couldn't tell me categorically which type of coolant I should use, the 'old' type, or the 'newer' one. They also came in different quantities/bottle sizes.

Has anyone done this job recently and can tell me which coolant is best to use? Or if it's going to be simpler/cheaper, then a non OEM fluid?

Cheers
 
Comma Xstream G48 is what I have used for years and equivalent spec to bmw's.
You can use pretty much anything that's blue, make sure it's not red.
 
To do this

Jack the car up evenly
remove the large under tray
find the radiator drain plug this on my car was passenger side and light blue remove this and let the fluid drain out (if you have pets don't let them drink it it is not good for them)
flush the system if you feel it is required
replace rad plug
fill with new coolant
mine tuck 5 ltrs
lower from jacks
start engine run for a short time and squeeze all the hoses you can to encourage air out of the system
go for a short drive (with any remaining coolant you have) to open the thermostat re check level top up as required

When happy it is all done
 
Bare in mind though that's not a full coolant change. To do it fully you need to get to the drain plug on the side of the block to get the coolant out of the engine which is a bit of a pig.

PDJ said:
To do this

Jack the car up evenly
remove the large under tray
find the radiator drain plug this on my car was passenger side and light blue remove this and let the fluid drain out (if you have pets don't let them drink it it is not good for them)
flush the system if you feel it is required
replace rad plug
fill with new coolant
mine tuck 5 ltrs
lower from jacks
start engine run for a short time and squeeze all the hoses you can to encourage air out of the system
go for a short drive (with any remaining coolant you have) to open the thermostat re check level top up as required

When happy it is all done
 
TomK said:
Bare in mind though that's not a full coolant change. To do it fully you need to get to the drain plug on the side of the block to get the coolant out of the engine which is a bit of a pig.

PDJ said:
To do this

Jack the car up evenly
remove the large under tray
find the radiator drain plug this on my car was passenger side and light blue remove this and let the fluid drain out (if you have pets don't let them drink it it is not good for them)
flush the system if you feel it is required
replace rad plug
fill with new coolant
mine tuck 5 ltrs
lower from jacks
start engine run for a short time and squeeze all the hoses you can to encourage air out of the system
go for a short drive (with any remaining coolant you have) to open the thermostat re check level top up as required

When happy it is all done

Yeah that's what I'm hoping to be doing, the full change. There are a few guides I've seen online to help with that part.

So I'll go the G48, think I might have a bottle of that somewhere already.

How much would be needed for a full change? I'm guessing two 4/5 litre bottles should do it?
 
I did mine without removing the plug in the block and it was around 4.5ltrs

What I did to get as much out the block as possible I used a light air pressure to blow it through I could hear it trickling through when blowing some air into the system.
 
PDJ said:
I did mine without removing the plug in the block and it was around 4.5ltrs

What I did to get as much out the block as possible I used a light air pressure to blow it through I could hear it trickling through when blowing some air into the system.

From memory it was around 8 litres out in total draining the block so you're missing a fair bit doing your method.
Kern47 said:
How much would be needed for a full change? I'm guessing two 4/5 litre bottles should do it?
Exactly.

Eta: just checked and it's stated at 10.7 litres capacity so either my memory or technique is out
:D
 
They couldn't just make it a nice round 10 could they... :|

But cheers, I'll get that bought and hopefully get it done while the weathers nice :thumbsup:

Cheers guys
 
TomK said:
Bare in mind though that's not a full coolant change. To do it fully you need to get to the drain plug on the side of the block to get the coolant out of the engine which is a bit of a pig.

PDJ said:
To do this

Jack the car up evenly
remove the large under tray
find the radiator drain plug this on my car was passenger side and light blue remove this and let the fluid drain out (if you have pets don't let them drink it it is not good for them)
flush the system if you feel it is required
replace rad plug
fill with new coolant
mine tuck 5 ltrs
lower from jacks
start engine run for a short time and squeeze all the hoses you can to encourage air out of the system
go for a short drive (with any remaining coolant you have) to open the thermostat re check level top up as required

When happy it is all done
Tom how important is it to drain the block too? I mean to make life easy you could change it twice from the rad a few miles apart as an example (I know that's not very scientific :?)
 
RedUn said:
TomK said:
Bare in mind though that's not a full coolant change. To do it fully you need to get to the drain plug on the side of the block to get the coolant out of the engine which is a bit of a pig.

PDJ said:
To do this

Jack the car up evenly
remove the large under tray
find the radiator drain plug this on my car was passenger side and light blue remove this and let the fluid drain out (if you have pets don't let them drink it it is not good for them)
flush the system if you feel it is required
replace rad plug
fill with new coolant
mine tuck 5 ltrs
lower from jacks
start engine run for a short time and squeeze all the hoses you can to encourage air out of the system
go for a short drive (with any remaining coolant you have) to open the thermostat re check level top up as required

When happy it is all done
Tom how important is it to drain the block too? I mean to make life easy you could change it twice from the rad a few miles apart as an example (I know that's not very scientific :?)
Well you could do that but you would still have mixed the old and new coolant. It would take much more coolant drops from the rad to get to an imo acceptable 'new' coolant with that method than doing it properly in the first place, which really isn't that hard once you've got to the drain plug.
 
Bit of a bump on this. Did the OP drain from the block as well? I couldn’t find the drain point a few days ago when I was swapping the rad. Can anyone point me at it in a picture?
 
pic04 (1).jpg
The ever useful pelicanparts site provides a good guide
https://www.pelicanparts.com/techarticles/BMW_Z4M/15-WATER-Draining_and_Filling_Cooling_System/15-WATER-Draining_and_Filling_Cooling_System.htm
 
Bugger i use Pelican Parts! never found that. However, i dont get it, its a drain but that bolt is on the top. Do i flip the car upside down 8)
 
If you're going to do it a good tip to avoid a load of coolant everywhere is to surround that area with decent kitchen roll paper. Try make a rough funnel and link the paper to your collector. Open the plug slightly and sit back for a few hours marvelling in physics not making a big mess of your job :)
 
I just did this.. I noticed that the pelican parts tell you to put the blue drain plug back in before opening the block drain hole.. I just undid the blue plug again after doing up the block drain, and at least another liter came out of the blue drain plug..

Edit: I also don’t have a heater system in the car anymore, so I wonder how much coolant it will take..

Re-filling atm.. slowly..doing 250 ml at a time and then letting it sit for 15 mins before adding more.
 
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