Using Water instead of Coolant

dos30

Hi I am driving an E46 BMW. I had to drive from Limerick to Dublin one evening and noticed that my coolant level was below the minimum. The motor factors were closed so I decided to top it up with water instead of the recommended coolant. I used about 1 litre, would this cause any problems in the cooling system? Will it have to be drained and refilled?

voxpop

There are a few past threads about coolant, loads of info in them. Coolant has anti-corrosive properties and also has a lower freezing point. You can get a yoke from halfords to check if you still have enough coolant to stop everything freezing in winter.

AlanAhern

I dont know if you have ever seen a cooling system with just water in it but its not pretty. This is over years of water though and not over night use.

Its advisable to use coolant only. But water will do but ONLY as a temporary solution.

Your best to get rid of the current water/coolant mix and refill mate.

dos30

Thanks Lads, I'll get it drained and refilled so to be on the safe side

JoeySully

im about to do this in my e36 next week.

i have read that using water is not good for you engine. can cause gasket failure / water pump failure / thermo and rubber pipe failure - but not from tempory use.
water is a conductor of electricity and if you use plain water then through a process of electrolysis you can get a build up in your cooling system.

when mixing coolant you should use distilled water which i haven't got yet but i have been told you can get it in any chemist

also always trust pink

Fratton Fred

isn't coolant just water and anti freeze with a few chemicals added to prevent corosion?

If you live in an area with soft water then there should be no need to use distilled water as well.

can anyone confirm this?

JoeySully

yeah thats probably true

hard water areas should not use it in their cars

pauln

JoeySully wrote: »

im about to do this in my e36 next week.

i have read that using water is not good for you engine. can cause gasket failure / water pump failure / thermo and rubber pipe failure - but not from tempory use.
water is a conductor of electricity and if you use plain water then through a process of electrolysis you can get a build up in your cooling system.

when mixing coolant you should use distilled water which i haven't got yet but i have been told you can get it in any chemist

also always trust pink

You could always just buy the ready mixed coolant, I use the Prestone stuff, kind of a acid green colour, comes in yellow containers.

rebel.ranter

JoeySully wrote: »

im about to do this in my e36 next week.

Hi Joey, air locks in the 6 cylinder BMW cooling systems can be a pain to get rid of. More importantly not removing them can lead to problems with over heating. Worse thing is your temperature gauge may read normal.
Just take extra care when you are doing it.

Assumes you have completely drained the coolant.

1. I normally park mine on a sloped driveway, nose up (or front up on axle stands).
2. I use the OE cooling fluid mixed with distilled water. I pre mix it in a large plastic jug. I couldn't be sure if any Halfords supplied or other coolant was suitable for my engine, I'm paranoid about brakes & cooling systems!!)
3. To pour in I cut to bottom of a 2L mineral bottle & tape the neck of the bottle over the radiator cap opening to make a good seal. Open the bleed screw fully.
4. Pour in a bit of coolant & start the engine. Make sure you have the temperature dial (blue to red dial) set to to full heat (red). Turn on the fan too at full blast, it makes it easier to check if the coolant is getting to the internal radiator.
4. Keep adding the mixture through your home-made funnel (I'm told top up the funnel to the top to prevent air-locks).
5. Coolant will eventually start coming out of the bleed hole. Ensure you let the engine run until it gets fully warmed up. Why?->
6. With the engine fully warmed up the thermostat will open & the level of coolant in expansion tank will drop, so top it up again until coolant comes out of bleed hole. Watch to see that there are no air bubbles.
7. Still with engine running check that the blower is blowing hot air, this will signify that there is coolant getting to the internal radiator.
8. Once you are sure that there are no further air-locks in the system (i.e. top up the expansion tank once more, watch bleed hole for bubbles). Then you can remove funnel & replace the bleed screw. Replace radiator cap also.

With an older car it is worth getting the radiator pressure tested to ensure that it is in reasonable order. Munster radiators near Proby's Bistro/Deans Hall (behind Beamish & Crawford) can do this for you. Also if you haven't already changed the thermostat & water pump now is a good time. There is time & cost savings to be had by doing them all at once.

slimjimmc

Most car manufacturers recommend you refill your cooling system every 2 years. Drain then flush with clean water (use mains water from a hose pipe) until water is clear and any crud is flushed out. Make sure to refill with the correct type of coolant, i.e. to manufacturer's specs. Electrolytic corrosion can occur if your coolant is not suitable for mixed metal engines.

More coolant info here

crosstownk

Long term you should use coolant. If you have a leak and are trying to find the source then use water until you locate the leak rather than wasting costly coolant. But don't use water as a long term coolant.

VH

Fratton Fred wrote: »

isn't coolant just water and anti freeze with a few chemicals added to prevent corosion?

If you live in an area with soft water then there should be no need to use distilled water as well.

can anyone confirm this?

tap water has salts in it