Tap water in engine coolant tank?
 

So the crappy story is my girlfriend took her car to a service station and let them fill some engine coolant fluid(which was very low in her car). However after she back she told me all the guy did is filling some tap water into the coolant tank.

I read an article telling all about the horrible stories of filling tap water as coolant. Are those true.

If so, is there an easy way that we can fix this problem? can we just buy some coolant fluid and add it into? Or do we have to do the flush and refill work?

Thanks a loooooooooot!

it's fine. if you're super worried about it just drain and refill the coolant system

Tap water will cause corrosion over time due do all the mineral within it.
Flush it few times and replace with distilled water.

Wait... Did they fill the cooling system with water only, or water and coolant? And did they just add a (relatively) little, or much more?

There is a 50/50 premix, so tap water should be fine. It depends how low is the coolant level when they add the tap water.

It also depends on your tap water ;)

Where I live we have very soft water...about 5ppm .....neutral pH

I have lived places that it is hundreds of times higher and acidic, so here tap water is almost as good as distilled...and the other place ate the copper pipes out of the house in about 4 years :)

Like Dan said, it depends on the water quality. Although I'd be leery of drinking water that was not safe to put into a radiator.

If they put in only water, and you live in a cold climate, I'd worry about the antifreeze being diluted this coming winter. You can get a coolant hydrometer for a few dollars and check that.

I'd also worry about why the coolant was low. If there's a leak, best to fix that rather than just keep topping up.

Ken

dont listen to mochie. he does not know what hes talking about.

Lol! i thought most everybody blocked him by now?

as others have said, it's not advisable to pour tap water into the cooling system but I doubt it's going to break thing either.
If it were me, I would flush the system just to be safe but then again, I'm paranoid like that.

If it was just a bit of tap water to top off the overflow but there was coolant (50/50) in the majority of the system, you should be fine.

Does this forum have that capability?

Monchie is one of the last people I'd want to killfile, but there are a couple of others.

Ken

Tap water is all people use when they use concentrated instead of premixed. Your fine but as others said make sure it's not all water. The hydrometers you buy will even tell you on a temperature scale how low your fluid is good for before it will freeze.

In all of my time here I only have one person on my block list. Guess who it is.



OP, it will probably be fine but like others have said, it's not a good idea to do on a regular basis and any leaks should be fixed properly.

fixed

Thanks for your concern.


I'll look into this situation, thanks.

No matter where you live there are impurities in your tap water... there is no if/ands/buts about it. The reason we used distilled water for radiators is because a few things need to be taken into consideration. First, tap water naturally comes to a boil faster than distilled water, not because the boiling point of the water is lower, but the volume of water against the impurities and contaminants of the water is far lower.

Also consider the mixing of metals when going from your radiator, to your hoses, through your motor, pump, etc. Tap water can have a range of pH which could cause corrosion and cavitation to pumps and metals. The use of an additive, namely glycol, increases the pH of the coolant and helps prevent the dangers of a low pH cooling system.

Lastly, tap water has more of a risk for carrying electrolytes picked up from plumbing sources. In theory, electrolytes can wreak havoc when it comes to mixing metals through electrolysis.

Now again, the above is all "in theory" ... I have heard stories of people running tap water in their rads for 30+ years without issue. Really all comes down to where you live like others have said .... but nevertheless ... why not just err on the side of caution and grab a couple jugs of distilled water from your local grocery/drug store? Surely you can spare a few bucks.

Your radiator is filled with more impurities than any city tap water would be. Just saying....

The glycol will change the boiling point (not by much) but more importantly it has superior heat transfer properties and lowers the freezing point. Most engine coolants run around 212 deg F anyway. I don't know if rotarys run hotter or not....


Distilled better than tap - yes. Any reason to worry about tap - no. Most important is you have a 50:50 or close mix and your level is good.

Stop freaking the OP out lol.

This is the truth! I would also add to ensure your system is pressurized. Which means a good radiator cap and no leaks. A pressurized system raises the boiling point significantly.

I would guess that well over 90% of the automobiles on the road have tap water in the cooling system. It's really not a big deal.

That's what I've always done. That's also all that I've ever seen garages use. Never any problems.

FWIW, I still fill my tires with air, not nitrogen.

Ken

You're DOOOOOMED!!! :SHOCKED:

We're enthusiasts here. We would never use anything but deionized water or a pre-mix 50/50 that already contains deionized water. As others have said even the best potable water contains some minerals. Sure, in the 70's we just used tap water, but thankfully we've evolved. ;)

The problem with using distilled water in the radiator or nitrogen in the tires is that nobody really sees that, so we don't get the image and the reaction.

I made a fuel cap hook, so the cap won't dangle against the paint. My friends all roll their eyes and say that the cap is not going to damage the paint. They're right (not that I'll tell them) but I get the proper OCD image across.

They fall in line pretty easily when I tell them no eating or drinking in the car. :)

Ken

seriously, no eating and drinking in the car. thats how I keep my interior almost pristine.

That's what my Hondas are for.

Easy to enforce if you have a fuel cap hook, a color-coordinated cover on your EZ-pass and a somewhat deranged look in your eye.

Ken