Tap water in the coolant tank?

[ziauris]

Hi all,

 

Car is 1.6L TR petrol Auris currently at 67,000 miles. Last serviced at 42,000 miles by Toyota.

I recently had my car serviced by an independent garage and found out that the water pump needed replacing during the oil/oil filter/air filter change.

As I hadn't planned for this and it was late on a Saturday, I only had around a litre of the toyota super long life coolant (pink). During the pump replacement, the mechanic took off the coolant return pipe to make sure the coolant was flowing with the new pump and topped up the existing coolant with what appeared to be normal tap water. It was at most around 1 litre of tap water that went in. I then put the 1 litre of pink coolant to top it off.  In hindsight, I shouldn't have let him do this. I have kept an eye on the engine temp and the guage stays in the middle where it normally is.

But will it do any damage to the engine to have this approx 1 litre of tap water floating around mixed with the coolant. As I understand it, the pink coolant is 50% coolant and 50% de-ionised water, so will putting ionised tap water damage it in anyway? Should I flush out the system ASAP or is it OK left for 1-2 yrs (8-16,000 miles)?

 

Thanks,

 

 

 

[Anthony Poli]

In theory it shouldn't harm things in the very short term, but the pre mixed coolant has anti freeze and rust inhibitors. I personally would only use it in a emergency to get me home or to a garage.

[yossarian247]

The water in itself is unlikely to do any harm I think. It used to be the norm to make coolant up by diluting pure antifreeze with tap water until quite recently. 

Also if you flush the system it's usually done with tap water, and it's virtually impossible to get it all out before adding fresh coolant,  so you'd only be flushing tap water with tap water! 

The only issue would be if it's left the antifreeze mixture slightly weaker than it should be, but you can easily rectify this by adding a drop of undilute antifreeze to the header tank. 

[fordulike]

As Nick says, coolant concentration is the important thing here. The tap water content won't be an issue.

Get one of those antifreeze/coolant testers, they're pretty cheap, and check the strength of the solution. If it is too weak, remove some coolant from the expansion tank using a turkey baster, then add some concentrated coolant to replace what you took out.

It'll be fine, don't worry

[tavy]

When concentrated coolant is diluted with tap water is not such a big problem as long as concentration is OK, but adding tap water frequently if cooling system has a small leakage, leads to big problems because tap water creates during the time limestone deposits inside the engine, deposits that impede a proper cooling of engine.