Radiator fluid low - The Unofficial BMW M5 Messageboard (m5board.com)

1bad540 · 25th October 2007, 18:24

I noticed my radiator fluid is a little low. Anyone know what to use to top off the radiator fluid? Thanks

Thunderbird · 25th October 2007, 18:32

How low is it, do you have a leak? If you have to refill it go buy BMW Antifreeze or you can add a little distilled water but whatever you do don't put prestone or any othe standard coolant in the tank the stuff in it will tear up your cooling system.

Bugeater · 25th October 2007, 21:56

You live in Texas? If so, then I suggest distilled water to "top it off".

jclyman · 26th October 2007, 00:45

If you want to put "approved" fluid in it, use ONLY BMW approved fluid (at the $tealer), but it is EXPENSIVE! (It's blue.)

1bad540 · 26th October 2007, 01:30

Thank you for all the replies. I purchased some fluid from the stealership.

jclyman · 26th October 2007, 03:05

Quote:

Originally Posted by 1bad540

Thank you for all the replies. I purchased some fluid from the stealership.

You still ought to watch for a leak ... radiator fluid goes down a little over time ... BUT, you don't want a leak to turn into a big time leak ... and, COOK your engine.

R748 · 15th December 2007, 03:04

Quote:

Originally Posted by jclyman

You still ought to watch for a leak ... radiator fluid goes down a little over time ... BUT, you don't want a leak to turn into a big time leak ... and, COOK your engine.

I noticed mine is about 1 notch below the full mark in the resevoir tank. How much loss is "normal", if any? I changed the thermostat around this time last year, and topped off the fluid. It was still at the top mark for months afterwards, but I did not check it regularly.

Today, the coldest day of the year so far, the "Check coolant level" came on, and thats when I noticed it was a notch below full.

mrrammstein · 15th December 2007, 22:44

Quote:

Originally Posted by R748

I noticed mine is about 1 notch below the full mark in the resevoir tank. How much loss is "normal", if any? I changed the thermostat around this time last year, and topped off the fluid. It was still at the top mark for months afterwards, but I did not check it regularly.

Today, the coldest day of the year so far, the "Check coolant level" came on, and thats when I noticed it was a notch below full.

it could be simply because of the fact that its cold, and it contracted - thats happened to me before

DouglasABaker · 16th December 2007, 04:23

Hold on here - so the only place to get approved coolant is the dealer?

There must be aftermarket choices, no?

d-

Thunderbird · 17th December 2007, 16:04

Quote:

Originally Posted by DouglasABaker

Hold on here - so the only place to get approved coolant is the dealer?

There must be aftermarket choices, no?

d-

No, there is not an aftermarket solution except just topping it off with distilled water. Prestone and those other popular brand coolants do not have the same chemical composition as the BMW antifreeze and that stuff will do carnal damage to your cooling system. Trust me I have seen it and you don't want to take the risk to save a few dollars.