Topping up coolant - what with ?

[WindsorRob]

Noticed the coolant level is a little down on my motor - E39 M5. What's the best thing to top it up with, I assume the same mix that was last put in at service. Anyone know if there's a particular BMW spec, or is it just the same as some off the shelf stuff ?

[FoundOnRoadside]

Water.

[kambites]

If it's only down a bit, just use (distilled) water.

[Whitean3]

I had this recently with my 911. As others say, if it's only down a little bit, distilled water should be fine. However, if it is down a lot (mine was WAY below the minimum level) I'd recommend you get some proper coolant. Your local dealer's spares department should have 1l and 5 l bottles; you may find they give you some coolant for free! I was amazed that the Porsche dealer gave me 2 litres gratis because they had run out of the small bottles to sell me.

I would also add that I have read that mixing coolants from different manufacturers can be problematic- the coolant can gelify- so always worth putting in the same stuff the servicing department uses, assuming the level is very low.

[kambites]

This is the advantage in servicing one's own cars. You know exactly what's in them.

[McSam]

kambites said:

This is the advantage in servicing one's own cars. You know exactly what's in them.

+1. The amount of people I get in at work saying they need some coolant, and upon me asking what might be in it already, they have no clue. Often going by a colour is OK - blue, mostly pink these days, orange on some Fords - but when the expansion tank is either a) empty, b) not present by design or c) coated in caked crap, you've got little chance of getting it right without guesswork.

[aka_kerrly]

Typically BMW blue seems to be fairly universal, part number is 82-14-1-467-704 , it is referred to as G48 from a company called Glysantin.

BMW can use up to 8L of coolant so a 1 gallon 3.7l bottle isn't quite enough so I'd get a 1 gallon + 1L for a full change or just a 1L for top ups.

[McSam]

He said the coolant is a "little down", why's he gonna need a gallon! Which is 4.55 litres, while we're about it

[aka_kerrly]

McSam said:

He said the coolant is a "little down", why's he gonna need a gallon! Which is 4.55 litres, while we're about it

Maths is clearly suffering today

The part number was off a gallon bottle but the main point was at least the OP will know exactly what he needs, better than saying some blue stuff....

[E38Ross]

BMW sell 1.5 litres for about 10quid and it's good stuff, dilute to 50 percent and away you go.

[WindsorRob]

Thx guys- kind of what I thought, I'll check the service records for what last went in and get some from BMW. Its always been serviced there.

[S. Gonzales Esq.]

Where did the missing coolant go?

[Captain Muppet]

S. Gonzales Esq. said:

Where did the missing coolant go?

No one wants to think about that, just keep topping it up and hope it's all OK.

[McSam]

aka_kerrly said:

McSam said:

He said the coolant is a "little down", why's he gonna need a gallon! Which is 4.55 litres, while we're about it

Maths is clearly suffering today

The part number was off a gallon bottle but the main point was at least the OP will know exactly what he needs, better than saying some blue stuff....

I was trying to figure out where you were going with the talk about a gallon plus a litre, because that ain't gonna do a change but it rather excessive for a small top-up

Mentioning G48 and the BMW part number was most useful, though

[davepoth]

S. Gonzales Esq. said:

Where did the missing coolant go?

Don't keep asking sensible questions!

[S. Gonzales Esq.]

Captain Muppet said:

No one wants to think about that, just keep topping it up and hope it's all OK.

To be honest, that's usually my reaction too

[10 Pence Short]

We had a disappearing coolant issue with a 2000 BMW 316- turned out it was a lightly holed radiator (and not HG, thank god!).

[sparks_E39]

Being an E39 it has a rubbish cooling system, my radiator went. My whole cooling system has pretty much all been replaced in the last couple of years.

[E38Ross]

sparks_E39 said:

Being an E39 it has a rubbish cooling system, my radiator went. My whole cooling system has pretty much all been replaced in the last couple of years.

Not just E39s, all M52 and M54 engined cars iirc. Mine had a new radiator in December 2010 and thermostat in December 2011, so is probably due a new water pump and/or header tank this December

It's did get 6.5 litres of fresh 50% coolant with deionised water about 1 month ago though to help

[McSam]

E38Ross said:

Not just E39s, all M52 and M54 engined cars

Stop iiiiiit, it might be able to hear you from here..