Tap water to mix with coolant...

[acewiza]

Last month I learned what seems to be a reliable way of getting ALL the old fluid out of a cooling system, quite by accident. I have this old car with unkown history which blew the bypass hose under hard acceleration, and then (obviously) needed a coolant flush/refill.

I've always used this method to try and ensure a complete flush, but this time I'm pretty sure I actually did. I leave a garden hose connected to the kitchen sink faucet running HOT water into the rad, with the heater on and the drain open to equal fill/drain rate. Then just let it run for awhile till the fluid comes out clear.

This time I'm absolutely positive all the old anti-freeze was gone. At one point after about 20 minutes I heard an odd noise and looked outside the garage to see the rad boiling over! Definitely couldn't have been much Prestone left in there! Running at least 214deg.F too I believe, by then.

Seems OK now, probably could use a new radiator/recore, though. Haven't had it on the road enough to determine the actual viability of the cooling system yet.

 

[Lumberg]

Don't any of you guys use the t-fitting on the heater hose and flush with the garden hose hooked up to it for a few minutes?

 

[Buford T. Justice]

I have always heard using tap water is a big NO NO and most folks that work on cooling systems don't know why and use it anyway.

The reason you don't want to use tap water is because it contains chlorine and fluoride. These interact with the silicates in most coolant when heated and leaves scale inside the radiator and in other places.

You can flush with tap water, but be sure to drain it all out of the engine block then flush 3 more times with just distilled water before pouring in your new coolant.

When I flush 3 more times with distilled, I let the engine run for about 30 minutes then let it cool down and drain both the radiator and engine block. On the 4th time, I drain just the radiator then fill it up with 100% coolant so it get about a 60/40 mix of coolant and water since there is nothing but distilled water left in the engine block.

 

[nobadges]

quote:

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If you live in Chippwa Falls Wis. (where buck teeth people live),then use tap water ,or if not use distilled water as RAY says,as he has good info on this subject,,,,,,BL

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What the heck does that mean?

 

[Lumberg]

Aren't there literally millions of cars out there today with hundreds of thousands of miles on them with tap water in their cooling passages?

 

[Matt89]

Lumberg - sure, mine is one of them.

I'd probably use distilled if I was going to go through the trouble of flushing, but I usually do what KenW does (premix)...

 

[Kestas]

Yes, and there are probably millions of cars that need new radiators every year. What's the point?

If you can avoid tap water, you'll be running a healthier mix in the cooling system. The calcium in tap water is considered a mild poison to coolant chemistry.

I've never gotten more than 13 years from any radiator, regardless of coolant maintenance. Admittedly, I've used tap water before joining BITOG.

 

[Matt89]

I'd love to see some data on how many radiators fail from the inside vs. outside. Seems to me road salt and bug guts would be worse for the radiator than tap water in otherwise functional coolant

It's deposits in the rest of the system that I'd be worried about, if tap water were causing them.

 

[nobadges]

I used tap water in my 98 neon for 2 years….but the worst kind…it was wellwater when I lived out in the boonies. Hard as heck, full of minerals.
Then the gradual overheating began.

Coolant flowed perfectly well through the rad…it just didn’t get cooled off.

When I put in the new rad last Spring, I pried the tanks off the old one to have a look.
Every tube had a coating of gooey brown muck inside.

That rad had several home flushes done on it with Prestone Super Flush and others….obviously without success.
Seems the muck didn’t block the rad completely, but it did act as very good insulation to the point that the rad was unable to throw heat off the coolant.

For me its now 100% distilled water to mix the coolant….or I buy the premixed stuff.

 

[Lumberg]

intersting the kind of contamination you got, just from using plain old water.

I guess you have to know about your water.

 

[nobadges]

Minerals is the killer I think.
I just stick with distilled now to be on the safe side.

 

[Lumberg]

I see, so in areas where the tap waters have less minerals, you may be more likely to get away with it...