engine block, distilled vs tap

GostRidr · 09-05-2008, 10:37 AM

I know that phosphate free antifreeze helps reduce issues but I've always read that it is better to use distilled water in the radiator. Is it okay to flush with tap water? The water isn't in there very long but is this enough time to leave behind deposits that will cause issues? On this same note, unless I drain the block (which I am trying to avoid) will the tap water that remains be enough to cause future deposits? I will obviously fill with distilled and phosphate free but that will leave a percentage of 'bad' water mixed in. Little things like this are big issues to my simple brain

Thanks!

hpservertech · 09-05-2008, 10:42 AM

When I do a flush I always wait a few days after the first one, and then drain/fill again. I dont think you will have an issue.

70SWT · 09-05-2008, 10:56 AM

Are you likely to cause any problems using tap water for a flush only? No..but given the age that these cars are reaching...why accumulate even one more possible molecule of residue. Use distilled water. It's cheap. Or at least use filtered water for the flush and then, as you said, distilled water for the fill.

I like to think we don't really own these cars, we're just caretakers for now...and the years ain't stopping...

2Tight · 09-05-2008, 11:44 AM

Tap water is fine to flush with as long as you know you are getting all of it out of the block and heater core. If you live someplace where your water is very hard it's much more important. If you fill a water glass from the tap and it looks like non-fat milk and sort of white until it clears, don't use it in your cooling system. I think where you live you get a blend of mostly Colorado River and some NorCal water; not the best stuff. Usually though during a flush there's not enough time for additional mineral deposition anyway. Doing a chem flush with any type of water doesn't matter at all as it's stripping the water passages of deposits anyway.

mattdavis11 · 09-05-2008, 12:33 PM

I've never used anything but tap water in mine. I think you are more likely to crack the radiator putting in the thermo fan switch, or it cracking on it's own, than ruin it via clogging b/c you used tap water. Then again, we can drink the tap water here. On the other hand, well water is a different story, and I have seen the damage it can do. Not pretty.

The first radiator in my car lasted 9 years but was toasted when my brother cracked it by overtightening the thermo fan switch. The second cracked on it's own after 16 years, and was used for over a year in that condition, and it still kept the car cool. I just put a new one in last weekend, and have zero reservations about the tap water that is in it.

I guess water quality standards are pretty lax in some areas.

flash968 · 09-05-2008, 01:14 PM

tap water bad - voids the warranty on newer models, as does coolant that contains phosphates - the amount of gunk in our water here in socal clogs up our pipes, let alone the small capillaries of a radiator

2Tight · 09-05-2008, 05:37 PM

Quote:

Originally Posted by mattdavis11

I've never used anything but tap water in mine. I think you are more likely to crack the radiator putting in the thermo fan switch, or it cracking on it's own, than ruin it via clogging b/c you used tap water. Then again, we can drink the tap water here. On the other hand, well water is a different story, and I have seen the damage it can do. Not pretty.

The first radiator in my car lasted 9 years but was toasted when my brother cracked it by overtightening the thermo fan switch. The second cracked on it's own after 16 years, and was used for over a year in that condition, and it still kept the car cool. I just put a new one in last weekend, and have zero reservations about the tap water that is in it.

I guess water quality standards are pretty lax in some areas.

You are lucky then Matt. In SoCal the water is very hard, often worse than most well water. It truly is not good for anything other than watering a lawn. It's not so much water quality standards that are lax but hardness isn't the same as chemical contaminants like organics and chemicals. My water in NorCal is from well sources and my pool tile looks like a salt flat it's so hard. Given a choice in Cali you should never use tap/well water in an engine unless it comes from a Sierra source. And yes, our water sucks! As a practicing corrosion engineer for the last 34 years I might be a bit cautious but distilled water is the way to go, at least for the final mix with coolant. Distilled water should never be used alone without corrosion inhibitors in any engine...it is very aggressive to aluminum and not that kind to cast iron either.