[Nicksa04]

Hi Guys,

Just ordered a new water pump and thermostat for my 335i 2008...

Can someone tell me what type of coolant i need?

Alot of the posts say to use the genuine BMW G48, but i have also read you can use Zerex G-05..

Any advice on this one..

Cheers.

[robbieredknapped]

Demineralized or distilled water is fine for top up

[R3N]

You really want to use coolant for anti corrosion properties. I would just stick to BMW fluid.

[dorkbydesign]

Anti-corrosion is pointless in a plastic/aluminium system.

Demineralised or distilled water is the most effective coolant.

[SPJ]

get the bmw stuff its not that expensive

[DR-JEKL]

Originally Posted by dorkbydesign

Anti-corrosion is pointless in a plastic/aluminium system.

Demineralised or distilled water is the most effective coolant.

Hmm maybe so but what about the lack of anti freeze protection? I'm also certain that distilled water would have a lower boiling point threshold also?

[Nicksa04]

Spot on guys can get it from the dealer for about $17 for 1.5 litres, i think a full flush will use about 3 bottles so $50 well worth it i think..

[dorkbydesign]

Originally Posted by DR-JEKL

Hmm maybe so but what about the lack of anti freeze protection? I'm also certain that distilled water would have a lower boiling point threshold also?

Mate, it's Australia. When is it ever going to freeze?

Pure water does indeed have a lower boiling point however 'anti-boil' properties of substances such as ethylene glycol only raise the boiling point by 1-3 degrees, factoring in the water pressure inside the radiator (around 225 kPa) which raises the boiling point to about 121°C and assuming a small logarithmic increase in boiling point caused by an ethylene glycol based coolant, the resulting boiling point would be 123-125°C. The difference is negligible.

The main reason coolant is added in other cars is because the engine block and cooling elements are not aluminium based and can rust and coolant is a brilliant rust inhibitor. However since our Bimmer engines and cooling elements are all aluminium, we are safe from this.

The main purpose of anti-freeze is simply to stop the coolant from freezing (you guessed it) in cold climates. That's why it says BMW Anti-Freeze on the bottle and not BMW Anti-Boil.

If OP is going to be parking on top of Mt. Kosciuszko in mid-July then he will need anti-freeze.

[doogee]

Coolant also keeps everything lubricated nicely.

Just because some of the internals are aluminum doesn't mean they can't corrode. Look inside any older motor from an E36/E46. You'll find corrosion in the coolant passages.

[Sans]

My e36 s52 engine had a cast iron block that's where the corrosion in the coolant passages is from (same with the e46 s54). The comparison btw e36 (or e46) and e90 is iron to aluminum which are vastly different metals with different corrosive properties.

[doogee]

Originally Posted by Sans

My e36 s52 engine had a cast iron block that's where the corrosion in the coolant passages is from (same with the e46 s54). The comparison btw e36 (or e46) and e90 is iron to aluminum which are vastly different metals with different corrosive properties.

Facepalm...


BOTH engines have aluminum heads. Which WILL corrode over time.

[DR-JEKL]

Originally Posted by dorkbydesign

Mate, it's Australia. When is it ever going to freeze?

Pure water does indeed have a lower boiling point however 'anti-boil' properties of substances such as ethylene glycol only raise the boiling point by 1-3 degrees, factoring in the water pressure inside the radiator (around 225 kPa) which raises the boiling point to about 121°C and assuming a small logarithmic increase in boiling point caused by an ethylene glycol based coolant, the resulting boiling point would be 123-125°C. The difference is negligible.

The main reason coolant is added in other cars is because the engine block and cooling elements are not aluminium based and can rust and coolant is a brilliant rust inhibitor. However since our Bimmer engines and cooling elements are all aluminium, we are safe from this.

The main purpose of anti-freeze is simply to stop the coolant from freezing (you guessed it) in cold climates. That's why it says BMW Anti-Freeze on the bottle and not BMW Anti-Boil.

If OP is going to be parking on top of Mt. Kosciuszko in mid-July then he will need anti-freeze.

I reside in an area that rarely sees freezing temperatures, but i have gone for weekends away in the bmw out the the blue mountains and oberon where the temps reach freezing point.

I don't think bmw produce coolant for their all alloy engines to rip consumers off, and just because its Al doesn't mean it cannot corrode...

At the end of the day its your vehicle you can do as you like, but from my perspective i would rather run coolant to protect my engine which is worth $10K+ to replace then save $40 by not using coolant.

[dorkbydesign]

Originally Posted by DR-JEKL

I reside in an area that rarely sees freezing temperatures, but i have gone for weekends away in the bmw out the the blue mountains and oberon where the temps reach freezing point.

I don't think bmw produce coolant for their all alloy engines to rip consumers off, and just because its Al doesn't mean it cannot corrode...

At the end of the day its your vehicle you can do as you like, but from my perspective i would rather run coolant to protect my engine which is worth $10K+ to replace then save $40 by not using coolant.

Yeah, it is always down to personal preference but since we all know BMW's cooling system is shithouse I'd rather look out for heat dissipation now and import a new engine, tranny and diff from Hong Kong later ~$2000 when the engine block is corroded (5+ years). Because after all since the engine is aluminium, the second it overheats, it's f*cked.

[xxxjecxxx]

Get BMW coolant and 1 Gallon of distilled water. After you change the water pump. Drain out all the old stuff. Get a 5 gallon bucket and mix the BMW coolant with the 1 Gallon of distilled water. Fill it up with the car off. I like to push down on the suspension to help get bubbles out. After it's full, run the car for 5 minutes, reopen the cap and continue to fill. Do that until it's full (it took me three times). When you are sure that it's full, use the bleeder screw very carefully to bleed out any left over air. Be extremely careful with the bleeder screw as they break very very easily. I would go as far as recommending to pick one up since you will be at the dealership. Good luck.

[dorkbydesign]

Originally Posted by doogee

Facepalm...


BOTH engines have aluminum heads. Which WILL corrode over time.

Demineralised water does not corrode aluminium lol lrn2ionicbond

[doogee]

Originally Posted by dorkbydesign

Demineralised water does not corrode aluminium lol lrn2ionicbond

Maybe if the inside of your motor was sterile.

[dorkbydesign]

Originally Posted by doogee

Maybe if the inside of your motor was sterile.

What does sterility have to do with it, I'm not eating out of the thing. Also all bacteria would be killed at operating temperature anyway.