Coolant advice

[mcremin85]

In the process of changing out thermostat and waterpump. Just removed parts found the waterpump was starting to break up. All look like first day parts.
Looking for advise regards flushing out the rest of the coolant.
Where else do I drain from? Also what type of coolant should I use and what quantity and mix ratio? Thanks

 

[Mazza]

There is a drain plug on the side of the cylinder , but on a 4 cylinder in a really awkward position , on the exhaust side towards the back of the engine. I never took mine out , but flushed the system by putting a garden hose into the heater hose and back flushing it. (Makes a mess )

I used a Motor factor Green Coloured Antifreeze, ( Morris’ ) but some prefer to use genuine BMW. Down to choice and what you want to pay. I haven’t had any heating problems since it was done. I also changed the thermostat and waterpump (Meyle with metal impeller).

Recommended mix is 50/50 antifreeze/deionised water

4 cylinder engine is 6.9 litres
6 cylinder engine is 10.5 litres

 

[mcremin85]

Thanks for the reply

 

[jonco]

There is a drain plug on the side of the cylinder , but on a 4 cylinder in a really awkward position , on the exhaust side towards the back of the engine. I never took mine out , but flushed the system by putting a garden hose into the heater hose and back flushing it. (Makes a mess )
........

Agree - it is a pain to get at so I did the same flush method as Mazza.
I use Comma X Stream G48 which meets BMW spec.
The M44 is a pain to bleed if you don't raise the front end - several posts about this.

 

[mcremin85]

Cheers for reply its a 6 cylinder so hopefully be ok.

 

[Mazza]

Cylinder drain plug position

 

[DrWong]

I have a six cylinder and drained from the radiator and the plug on the side of the block. The engine block plug needs a new crush washer when it's refitted. I bought several from BMW for pennies.

I just bled from the expansion tank on level ground and had no problems. The expansion tank is right at the back of the engine bay on my car, so raising the front would've made the top of the radiator higher than the the tank.

I refilled with 50/50 BMW coolant. The price difference (a few pounds) was marginal for the peace of mind knowing the right stuff was in there. BMW is blue and what I drained out was green, but it had been running fine before then.

Re: thermostat, the OEM Wahler has a known design flaw with the electrical connector leaking. I had this unfortunately, so had to replace a Wahler stat I'd fitted with a Behr one (also OEM) after about a year. No problems since though.

 

[abh29]

We used BMW and mixed 50/50 with Distilled Water. It had never been changed in the 8 years we have had the car , and as the pump ect seemed original it could have been in from new. Car has never consumed water. It was changed as the fan coupling was worn , so as we were stripping the area deceided to also renew the Water Pump,Thermostat,and Belt idealer (all Febi from Opie Oils) the belt (from BMW) and the coolant.