1999corvettels1

I am planning on using distilled water with dexcool, while putting on my new Dorman coolant tank.

Water is pretty hard in Arizona, I changed it all out in 2009 and I think I used 10-12 gallons of distilled water, draining, filling back up, driving with heat on(probably circulates with heat off anyways?)

Did that until water draining out looked clear.

Maybe using a flushing kit and water hose would be better?

c4cruiser

While the Dexcool bottle says to just use tap water as part of the fill, if you have issues with minerals in the local water supply, it would be a good idea to used distilled water. Around here, grocery stores sell distilled water for about $1.00 to $1.25 per gallon.

For a complete refill, you need 2 gallons of Dex and 2 gallons of water. It's cheaper to buy the Dex in concentrated form and mix it compared to buying the 50% pre-mix stuff. And you can still keep any leftover coolant.

Consider swapping out the two radiator hoses at the same time if the ones on the car are original.

1999corvettels1

Is this a bad idea, was thinking of draining the coolant out of radiator, fill back up with distilled water.

Drive the car to my gf house in Chandler AZ, 66 miles round trip, then drain that out tonight, or tomorrow.

I'm going there anyways, was thinking the fresh distilled water will circulate all through engine radiator heater core thermostat.

But, would this cause a risk of the water boiling in the engine and blow a head gasket or worse?

It's mainly freeway driving and high of 100 degrees today.

Last time I did this I just cruised around my neighborhood and it was about 65 degrees out.

Also turning the heat to full hot and blower on is probably not necessary to have the water run through the heater core, will it do that with no heater and AC on?

1999corvettels1

I did buy a Lisle spill free funnel to help bleed the air out of the coolant, worked great on gf's PT Cruiser bleeding out the bubbles as the coolant can expand up into the funnel when T stat opens.




The cap screws onto the tank just fine, but the adapter pipe doesn't fit tight, with cap tight I can jiggle the adapter up and down slightly.

Hmm, not sure if this would work.

1999corvettels1

1999corvettels1

New Dorman tank came with 18 psi cap, original cap was 15 psi.

1999corvettels1

I see why it fits loose, it's meant to go on a radiator, where a radiator cap would go.

Hmm maybe I can drill out the old cap so the adapter pipe could slip through it and the cap seal the tank.

Might be more trouble than it's worth.

1999corvettels1

I took the big o ring/washer off the bottom of the adapter pipe and slipped it on the top, underneath where the adapter cap presses on.

Now it has a tight fit, I think it will work!

LoneStarFRC

No need to turn heater "on". There IS no heater control valve that shuts off coolant flow through the heater core on C5s.
IOW, water/coolant circulates through the heater core full time. Any additional engine "cooling" by turning the HVAC control to "heat" and then turning the blower to "high" would be very minimal.

Route99

Think your using distilled water is great. We lived in AZ 3 times. Loved it, but, you're right, the water is very hard! We have a water softener system in our NC home and still use distilled water for our vehicles. Cheap insurance if it extends the life of the cooling system and ultimately the engine.

~Josh

Taking my engine apart I notice the steel water pump bolts are corroded where they touch coolant. Makes me wonder about the cylinder liners.

When going back together I'm flushing out the dexcool and refilling with green. Done with red.

1999corvettels1

Why green and not dex cool?

~Josh

I run a multi-location heavy equipment repair shop. I've seen red eat engines from the inside out. I know the service bulletins from all the major manufacturers. Proof is out there, tons of it. Simply use google and you should have plenty of reading info just on the 1st couple pages. I've seen it all in person.

Do what you want with your cars; I'll do what I know with mine.

~Josh

Bought the car back from a guy I sold it to 6 years ago.

I see it has red in it now. Taking it apart I see pitting.



They were smooth when I put them in 8 years ago. I remember because I purchased them new and polished them.

Will change coolant back to green.

~Josh

Should've seen them before I cleaned them up. The pits were black and the shank mottled. Wire wheel'd the shanks, hit the heads with a buffer and a quick pass down the shanks.

Functionally they are fine so I'm reusing them. Last time I threw money at the car which I still am now, just right now its clutch/trans/torque tube getting the most money.

1999corvettels1

I drained then refilled with almost 2.5 gallons distilled water, ran with spill free funnel about 15 minutes, then it went wild all of the sudden and puked coolant out of the funnel.

Shut off engine right away and it continued to overflow, then stopped.

I think that was the thermostat opening, as it expanded the coolant, also the clear water in the funnel turned red immediately.

On gf's pt cruiser the funnel could overflow but if you turned off engine right away as the level started to rise it would not overflow, corvette was much different.

I drained that coolant/distilled water, is it safe to slowly pour in my next round of distilled water?

Or wait?

I have 3 more gallons sitting out on the driveway soaking up the hot Arizona sun so it's not too cool.

~Josh

It's a sealed pressurized system. It's going to try building pressure and puke.

If it was me, I'd have the radiator drain opened and let it drain as I added water as needed until the drain runs out clear.

Then I'd shut the engine, let the radiator fully drain. Close radiator drain valve, and refill with concentrated (not 50/50 mix) green. The water in the block should even out the mix.

1999corvettels1

After flushing 7 1/3 gallons though, good enough?

~Josh

Yep. Done.

-Your drug screen has come back negative.

1999corvettels1

Just finished the belts and idling engine and coolant on floor.

Is it possible to overfill the coolant tank?

It appears coolant is coming out from the cap area.