j.kenzie@sbcglobal.net

Hi guys,
I am planning to change my coolant from whatever is in it now(90% sure it's Prestone extended life mixes with any coolant), to Zerex G-05. I thought I would drain the current coolant, fill system with distilled water, run it up to temperature, then cool and drain. Then I would put in the G-05 mixture. Does that sound good enough to get out old material.
Thanks,
Dave

Landseer

More than adequate.

Your a better man than me.

I'd drain and refill as in one fell swoop, no rinse, especially if I lived in Chicago facing polar vortex.

Maybe run a little distilled water thru the block drains while still uncorked from draining.

andy-gts

I have heard G05 always recommended on these pages and I just use the porsche coolant cause thats what the engine builder recommended....so I will stay with it....

j.kenzie@sbcglobal.net

G-05 = $15/gallon. Porsche coolant $70/gallon. Greg Brown uses G-05 in non-GB rebuilt engines, I think.
Dave

Mrmerlin

I would use the G05 coolant,
drain out the radiator, then pour half a gallon of distilled water into the top hose inlet let it drain. refit the plug.

with the block drains removed ,
and the one inch hose disconnected from the water bridge and going into a bucket
disconnect the heater valve and pour some distilled water into the heater core to flush it ,
then do the same for the cooling bottle, the water will rinse out of the lines and the coolant bottle.

Pour some water into the cooling bridge port so water comes from each block drain
Reconnect the hoses, and refit the block drains,
and refill with 2 gallons of distilled water and 2 gallons of full strength G 05

NoVector

I've tried your method, Dave, and it took a surprising number of cycles to get the drained water clear. I now drain the radiator and engine block and then take a garden hose w/ sprayer and put it in the overflow tank and blast away and let copious amounts of water drain out the three holes. Once I'm happy that it's clear, I then do what you describe - refill with water only, get it up to temp (with heater on), let it cool, then drain and fill with distilled water/coolant. I'm sure it's overkill, but we've all heard the horror stories of coolant gelling when it's mixed with other coolants. Of course with G-05 you'll never know as it's clear.

j.kenzie@sbcglobal.net

That sounds good. I don't have access to a hose until Spring. Maybe I should run a few more gallons on H2O cycled through before the final fill.
Thanks,
Dave

SeanR

Pull the rad plug, pull the block drains, remove hoses and if you really want to flush it pour some water from jugs in the block and rad and let if flow.

GregBBRD

Now, now....Porsche coolant expensive enough without creating "Internet Myths".

Porsche coolant retails for $49. Pretty "deep" margin on that coolant. I sell it to everyone for $39 and still make a tidy profit.

If you guys were taking apart and repairing the damage that I see on these engines, everyone would have a completely different attitude and these "alternative coolant" threads would not exist.

I just took apart a 100,000 mile GTS engine that coolant leaked between the head gasket and the acid eaten cylinder head. The engine was then cranked over with a cylinder full of "cheap" coolant, and split a cylinder, ruining that piston and rod.

Try to imagine what that is going to cost to repair....take a "wild guess"!

$500 a gallon coolant, over the life of the car, would seem like a bargain!

While I'm certain there are maybe a few people out there, in the US, that could take this engine aoart, repair the damage, and make it run another 100,000 miles, that list is probably pretty short.

I call that "job security".

dr bob

At my first full change I ended up with the top hose disconnected from the radiator at the radiator end, hose turned up so I could put the hose in with lower hose removed and thermostat out. Lots of water went through. Then move the top hose to the top of the radiator and pour a mess of water through that too. New thermostat, restore all the hoses, and refill with coolant and distilled water. The piece I missed and should have paid more attention to was making sure the heater core was completely flushed.

FWIW, at my first coolant service I was too timid with the block drains. It seemed that they were way tight and I wasn't ready to risk really pulling on them. I ended up doing the full hoses-off garden-hose flush, a few gallons of distilled through the block to clear the SoCal mineral slurry out, close and refill. I've been into the radiator with a mirror and then an inspection camera since, with no evidence of mineral plate-out in the bottom radiator passages where I'd expect to see them if there was much left in. Better coolants do a pretty good job of binding up any minerals. Over time the mfrs are moving away from high phosphate packages because they interfere with other more contemporary additives.

GregBBRD

^^^^^Sorry for the sermon, but I can't make it often enough.^^^^^

Regarding the OP's question....go to Walmart and buy 10 gallons of distilled water. ($.94 a gallon.)

Drain the block. Drain the radiator. Re-install the plugs. Fill the cooling system with tap water.

Run the engine until the thermostat opens and hot water flows through the radiator. Drain and re-fill.

Do this twice.
​​​​​
Do this two more times. Except with distilled water.

Fill the system with Porsche Coolant and distilled water. Alternatively, you can run G-05, if you're engine isn't "fresh" (the thought being that almost anything is better than acidic green or yellow coolant.)

Hope that your head gaskets aren't already so deteriorated that the time and effort you just went through is worth it!

j.kenzie@sbcglobal.net

Well OK. That's what I'll do. So I don't get it wrong what Porsche coolant should I get? I see one with G-40-91 EF.
Thanks,
Dave

GregBBRD

I changed/corrected my post.

I got so into my sermon that I forgot there was another alternative, which I use in my own shop under certain circumstances.

Anything that has a "fresh" set of head gaskets or has new factory water hoses with a new factory water pump gets Porsche Coolant.

Porsche coolant that I use is 000 043 305 75.

j.kenzie@sbcglobal.net

Thanks, Greg. I ordered the Porsche coolant. I found it discounted under $30 online. The $70 coolant was a different part number.
Dave

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