Is it worse than death to top up coolant with a bit of tap water?

The bimmer got slightly low yesterday so I stuck about 1/2 a litre of water in - will get the cooling fluid changed at the next service (in 4k miles). Of course it's the finest, softest Cornish tap water...

Done the same in my other cars - they say take it into a dealer but 2+ hours (and probably £100) away from work for a tiny top up seems a wee bit OTT.

 

No problems at all. Anti-freeze does what it says on the tin, and is not essential in the current weather (believe it or not) and also includes some rust inhibitors. Most places will use concentrated solutions and dilute it with tap water anyway, so all you are doing is slightly reducing the concentration

 

Cheers! The manual makes it sound like it's worse than topping up the engine with olive oil! Some things need doing "properly" (expensively) other things don't it seems.

No doubt my first service will cost me about a zillion quid.

 

Why is it using water though, only during my Rover ownership did any car I have ever owned use and coolant, ever !


I would check the cooling system over for leaks, perhaps get it pressure tested and check your warranty in case its head gasket, turbo bearings or something like that, I can understand a bit of oil usage but using coolant these days is unusual.

 

Water Pump maybe, just had one swapped on one of our vans,

 

Only engines that I have ever had to top up have either been leaking through hoses/rad or headgaskets.

 

Likewise, never had to top up coolant on a car unless it was leaking from somewhere. Was the return pipe from the turbo that leaked on my old ScoobyDoo.

 

Oh great - now I can do some worrying!

 

Do you have a warranty?

 

I'd be concerned about having to put half a litre in, not from a 'coolant' point of view, more where it's going! Have a good look at the radiator / header tank, they have a habit of cracking.

 

Yes - four months left.

I'll give the engine a good once over later on (currently being driven by the missus).

My Astra needed the odd top up and never had a leak anywhere. If I don't see anything obvious, I'll just mention it when it gets serviced in a few months time.

 

I found the coolant level on my S4 down yesterday, topped up with tap water then checked again after 50 miles and it was down again. There was a drip by the drivers side bumper.
Took it to my local indy this morning, I was hoping for a hose but unfortunately it was a corroded auxillary rad.
Good luck Mattee!

 

Take the main oil filler cap off, does it have any deposits that looks a bit like mayonnaise on it? Also have a squint into the rocker box through the oil filler hole and see if you can see any of the same. Couple of my colleagues have 335 diesels (at least I assume that's what you have from the avatar?) and they have both had head gaskets go

 

Well the level has stayed exactly the same (100 miles later) and I can't see any leaks. Might be okay...

 

I'd do more than just mention it, if you can't find the source keep looking until you can, test the coolant for hydrocarbons etc.

Also give it lots of repeated torque to get the cylinder pressures and temperatures up to help find any leaks.

 

The coolant level on my 996 fluctuates quite a bit occasionally.
Can be down to minimum and then after a good run can be back up to max.

Had to add a bit of water but never found any leaks and it runs ok.

 

Rang BMW - the 335d does occasionally lose a bit of coolant and uses oil more than I thought - so topped it up after a full inspection with a torch - no mayo, just a clean looking engine (with diesely oil on it!).

I think it's fine.

 

Some coolant will evaporate out, half liter in a year wouldn't worry me.

 

Get it pressure tested if it still loses coolant.

 

Will do - service soon so will get the full works done on it.

 

I hope that was Porsche approved water or you'll invalidate your warranty