jason556

Hey guys, do I topped off my coolant twice because the sign came on that it was running low. Both times I filled it up with 50% coolant/50% tap water. I was wondering how bad that is. I didn't really know much about cars back then so I didn't think too much into it. I just wanted to know if you guys think that's really bad. I was going to flush out the whole system soon. Thanks.

Plutoe

Back then------was that a month ago or when you were FA with your Dad's car------In any event it depends on what your definition of tap water!! Not all water is the same.----What is yours??

PS: If this is a true story, I would be more concerned with the leak in my coolant system vs the quality of water added!!

AMGAffalterbach

Lmao wow.

To OP, Plutoe is asking if you have a coolant leak issue, or if you just topped it off. Either way, you should always use distilled water mixed with coolant. I don't think it's too bad in the short term. But doing a coolant flush isn't a bad idea.

mersum1es

I agree with plutoe about 'definition of tap water'... I have never used distilled water in any of my cars, but on the other hand our 'tap water' is always fully drinkable and low calsium/iron(rust) content...

boardboy330

If you have chlorine in your water as does most of the US...it can cause oxidation and pitting...causing issues. You should always use distilled water. Also use the correct coolant and don't mix.

jason556

Lol no, two years ago I bought a used E350. I live in NYC and I used the tap water here. And yeah, you guys are right, I should check for leaks. Have to do it soon, winter is coming lol.