Coolant for E39?

[LikesBikes]

Hi all.

Will be replacing my auxilliary water pump soon and find myself wondering which coolant I need to refill the system. Is there an aftermarket brand that meets BMW's spec or is it best just to use the BMW branded one? A nose round the internet reveals some bewildering discussion on this and no solid answers so I'm leaning toward the OEM stuff from the dealer.

Cheers gang,

Darren.

[E65Ross]

I only use the oem stuff, it's not really that much more expensive than the cheaper alternatives. There is an alternative but I can't for the life of me recall what it's called. I know Amazon sell it! Make sure you use distilled or deionised water, too.

Edit - just remembered, it's called Comma G48 coolant. Amazon search it and you'll find it.

[Depthhoar]

LikesBikes said:

Hi all.

Will be replacing my auxilliary water pump soon and find myself wondering which coolant I need to refill the system. Is there an aftermarket brand that meets BMW's spec or is it best just to use the BMW branded one? A nose round the internet reveals some bewildering discussion on this and no solid answers so I'm leaning toward the OEM stuff from the dealer.

Cheers gang,

Darren.

Have a look here for an aftermarket solution to your problem:

http://www.commaoil.com/passenger-vehicles

There's an awful lot of twaddle out there on the internet about the relative benefits of OE fluids over reputable aftermarket brands. BMW don't make coolant, they buy in stuff from well known (sometimes not so well known) manufacturers of the stuff then label it up as their product for sale in their dealerships.

Some people buy into OE branded stuff because 'only the best will do' for their P&J. If the branded stuff is the same price as less well known but equally good coolant/oil/screenwash/air fresheners/whatever then fine, buy the BMW stuff. There's a huge amount of uncertainty/fear amongst car owners about issues like this and the car brands understand this and exploit it to their own financial advantage. (We're talking fluids here not parts, which is an entirely different argument with often different outcomes.)

I've just looked at the official BMW TIS for my E39 M5 and BMW list 14 other approved (apart from themselves) suppliers/manufacturers of coolant for my car. I live in one of the coldest parts of the UK, Comma coolant is in my Beast and the engine hasn't exploded yet, nor will it.

If you think forum arguments on coolants are bewildering try engine oil! There's a massive amount of argument on M5board about which is the correct engine oil (as well as the correct viscosity) to use in the S62 engine of the M5. My take is that the engine and oil for it were developed back in the 1990s, but engine oil chemistry - particularly in Europe - has come on leaps and bounds since then. Using a modern properly specified & approved (both v.important pre-conditions) oil will be cheaper and give the same if not better protection for the engine than the Castrol TWS stuff BMW specify/sell themselves. TWS is ridiculously expensive. Technology moves forward: t'was ever thus.

[E65Ross]

The only difference is that the comma stuff doesn't work out THAT much cheaper.....because concentrated goes to -36, yet the BMW goes to almost -70; so once diluted the price difference becomes a hell of a lot smaller.

But yes, agree about the OE/vs non-OE (hence I even suggested the same stuff as you!)

[Denis O]

Whichever coolant you use, make sure, when you refill, that the car has it's nose in the air. Makes it much easier to bleed the system.

[Depthhoar]

E65Ross said:

The only difference is that the comma stuff doesn't work out THAT much cheaper.....because concentrated goes to -36, yet the BMW goes to almost -70; so once diluted the price difference becomes a hell of a lot smaller.

Are you sure? The BMW OE stuff, with correct part number for my M5, says this:




50% solution giving protection down to -40 degrees C.

The entire Comma OEM range at 50% solution protects down to -36 degrees C.

(That's a minor difference of 4 degrees there certainly not as wide as 34 degrees.)

Maybe you're confusing the pre-mixed Comma stuff with the BMW concentrate? (Or possibly, the BMW OE windscreen washer fluid which gives protection down to -65 degrees undiluted??)

Perhaps there's a higher spec BMW OE coolant with a much lower temp capabilities? Would be genuinely interested to know about it if you've come across it.

Edited by Depthhoar on Saturday 18th October 16:57

[helix402]

This meets BMW spec: https://www.motul.com/system/product_descriptions/...

As does this: http://cars.febi-parts.com/vehicle.php?r_manufactu...

Or you can buy BMW branded coolant, which looks remarkably similar to the Febi Bilstein stuff. Or there are lots of other brands that meet BMW spec. These are just two I use.

[E65Ross]

Depthhoar said:

Are you sure? The BMW OE stuff, with correct part number for my M5, says this:




50% solution giving protection down to -40 degrees C.

The entire Comma OEM range at 50% solution protects down to -36 degrees C.

(That's a minor difference of 4 degrees there certainly not as wide as 34 degrees.)

Maybe you're confusing the pre-mixed Comma stuff with the BMW concentrate? (Or possibly, the BMW OE windscreen washer fluid which gives protection down to -65 degrees undiluted??)

Perhaps there's a higher spec BMW OE coolant with a much lower temp capabilities? Would be genuinely interested to know about it if you've come across it.

Edited by Depthhoar on Saturday 18th October 16:57

Ah, my apologies. Got my figures mixed!

[LikesBikes]

Thanks all, very much appreciated. However as luck would have it I came home and had a poke about and I seem to have fixed the problem (electrical connector not quite connected I think?) so no need for a new aux pump now.

Advice still useful though as I'm thinking she must be due for a coolant swap, many thanks.

[SuperHangOn]

E65Ross said:

I only use the oem stuff, it's not really that much more expensive than the cheaper alternatives.

I was quoted £11 per litre for concentrate antifreeze at the BMW dealer (Kentish town) a few weeks ago (my V8 needs 12 litres of coolant!). I used generic pre-mixed stuff from ECP in the end (not ideal but said it was ok for alloy engines on the tub).

BTW Im sure you're aware but the cooling system is a weak point on these cars. Once I started prodding about on mine, I noticed the expansion tank and rad were slightly leaking. I ended up changing the water pump, stat, a few hoses and the fan clutch while I was at it.

Edited by SuperHangOn on Sunday 19th October 16:54