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Topping up Coolant - Can I use tap water?

Topping up Coolant - Can I use tap water?

Author
Discussion

s3londonuk

Original Poster:

110 posts

70 months

Sunday 18th December 2011
quotequote all
As above, my 2001 S3 has just dipped under the Min level and I wanted to use a small amount of tap water to top up.

Is this OK?

Also, same question for a Focus 2005 TDCi!

Thanks

CDP

5,144 posts

159 months

Sunday 18th December 2011
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Probably best to use the correct Audi compatible coolant. If it's _just_ below min you should be able to get away with driving it to the VAG dealer, if topping up with water try a hard-water filter first.

Nick3point2

3,621 posts

85 months

Sunday 18th December 2011
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If it's only a small amount just use tap water, but if you have to do it regularly, as in there's a leak, alternately fill it with neat anti freeze, then water etc to keep the concentration.

cuprabob

2,834 posts

119 months

Sunday 18th December 2011
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I would top it up with some G12++ coolant mixed 50:50 with water. I tend to use deionised water as it's cheap and readily availble just to be safe.

G12++ costs around £8.50 for 1.5litre bottle and it's worth having a bottle for little top ups.

As said above if you find you are having to top it up frequently then you need to find out where it's going

Mojocvh

16,837 posts

167 months

Sunday 18th December 2011
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Hmm tempting but I'd go to haulfords and BUY the correct [ie matching]colour coolant and use that. IMO of course.
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TDIfurby

1,960 posts

80 months

Sunday 18th December 2011
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For a small top-up just chuck water in. A dribble is not going to affect the overall dilution of water to coolant, and is a better short term option than running very low...

If you keep needing a dribble it might be time to check the radiator and other things for leaks. A 2001 car's radiator is probably reaching a point where it might start failing.

LuS1fer

32,293 posts

150 months

Monday 19th December 2011
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I'd use de-ionised water as it's very cheap and doesn't have the lime deposits in it that will eventually block your radiator. A small amount probably won't do much harm though.

morgrp

3,929 posts

103 months

Monday 19th December 2011
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I've always used tap water to top up and never had a problem with any car.

va1o

14,878 posts

112 months

Tuesday 20th December 2011
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Why not just buy some, its not exactly expensive. I'd be questioning more why its got below the minimum level myself though, if you need to keep topping up then there's a leak somewhere.