Dexcool Coolant Flush

[Celica Man]

Is it safe to do a coolant flush using water from my garden hose? I was told I must use distilled water for my specific engine since it uses dexcool coolant. Same goes when mixing with water. Is this true? Apparently there’s a bad chemical reaction with regular water and dexcool. This doesn’t sound right to me.

Topic

[PaulKim]

I think it is more a matter of you don’t want who knows what contained in garden hose water circulating through your engine. By me distilled water is like $1 per gallon, why not use it?

When I did my coolant change i drained the radiator, filled with distilled water, then ran the engine with the radiator cap off and drain open and kept the radiator topped off with distilled water. then I drained that and filled with coolant and ran the engine again doing the same with coolant. then bleed.

I flushed because my car was repaired from an accident and they put in some green coolant and I was under the impression only honda coolant should be used.

My method may be wrong but to answer your question, why risk it when you only need a few $ of distilled water.

[John Hugon]

I like PaulKim’s advice on distilled water. Depending on where you live, water minerals will start electrolysis in a very short period of time.

I don’t know what type of water GM put in their coolant system along with the Dexcool, but it was a formula for electrolysis along with many unhappy customers.

As a suggestion…(I’m a green freak)…recycle the coolant coming out of your coolant system.

[Bill]

I think that using distilled water is the best bet but I have seen a lot of coolant manufactures lately stating to use drinkable tap water so who knows what’s best.

[EricTheCarGuy]

Honestly I’m not a fan of ‘flushing’ cooling systems as a maintenance item. Unless your system is full of sediment a flush is not necessary. I would recommend just a drain and refill at regular intervals and that should be enough to keep your cooling system in good health.

[John Hugon]

This is the reason GM vehicle owners are flushing their coolant systems. After seeing some of the coolant system/engine damage from electrolysis throughout the last few years I had the privilege to work on their cars/trucks,( :woohoo: ) I can’t blame them…..
Eleven years ago GM introduced an engine coolant called Dexcool. It’s supposed to last 5 years or 150,000 miles but there have been problems with this coolant. Cooling systems that use Dexcool exhibit more acid buildup and rust in the system when the coolant level gets low and oxygen is allowed to enter the system. The acid eats away at head gaskets and intake gaskets. Rust builds up in the system, inhibiting coolant flow, which causes overheating. Overall, numerous cooling system problems have been attributed to the use of this controversial product, although GM sternly stands behind it. There are class action suits against GM on this issue, but no settlements have been made to date.

[Lorrin Barth]

The thing about tap water is it may be coming from a mountain stream or a well drilled three hundred feet into the ground. The human body is a marvelous machine, it will tolerate a lot of dissolved stuff in water.

Where I live the water is non-depositing meaning it does not lime up pipes. It will also dissolve the solder out of a copper radiator and dissolve copper pipes. EPA recently required the city to introduce a chemical into the potable water supply in order to reduce the amount of copper people consume.

So, you must be thinking the water here is terrible. Quite the opposite, this area is known for its great drinking water.

I’m just saying what tap water tastes like to your palate and what it does to your engine can the different. And everywhere tap water is different. I am a fan of distilled water for cooling systems.

[Celica Man]

Thanks for the replies guys. My phone died on the way to my buddy’s place so I wasn’t able to read these replies. We used water from his hose to mix with full strength and then tested for the correct blend. I guess we’ll see what happens. If I start seeing anything funny, I’ll just dump it all again and use distilled water.

JTF, is there a test kit I can get that will tell me if there’s been a chemical reaction in the coolant that could lead to some crap eating at my gaskets?

[John Hugon]

Celica Man,

Sorry I didn’t see your question until now. I know someone that’s still working in the field and this is what they sent me on the subject and diagnosis of electrolysis in a coolant system. I always used a DVM to check for electrolysis.

How to test for electrolysis

Another link with some info:
http://www.fordforumsonline.com/threads/electrolysis-in-the-cooling-system.67/

Another issue that’s discussed in the Ford forum is high resistance in grounds. With the high output alternators /generators on today’s vehicles the first thing I would do is use Eric’s check on diagnosing bad grounds.

[zero]

Part of the whole Dexcool thing is the silicone in it. It’s made lot’s of people lots of money doing head gaskets and intake manifolds. 👿

As far as I’m concerned if you live somewhere with a municipal water supply, the tap is fine. That being said I’ve never actually done the water calculation. I suppose it wouldn’t cost that much, unless you drive a big diesel that takes 20+ liters.

[Rereonehundred]

My drinking water is pretty soft without too much mineral content.

But a few years ago, people in a nearby community had their tap water under chlorinated with a few people dead and many sick. So now the tap water is almost like Chlorox. The chemical reactivity of these chlorine compounds is so high I don’t even like to wash my car with it.

So it is distilled water to dilute the commercial coolant for me in the cooling system.

[Author]

Replies