Coolant change?

[GTP091]

Time for a coolant change as I’m replacing a few hoses on the GTP just because I want to have new.  Currently and always have ran the recommended orange dex cool.  Never had any issues with it. But wondering if anyone has some decent insight on if there’s any benefits for corrosion resistance or other benefits to switching to HOAT yellow coolant? I’ve read up lots on this and I run gold in my f150 but can’t find any opinions on switching to the latest. The yelllow stuff sounds like it has even better corrosion inhibiting properties than dex but maybe there’s some cons I’m not aware of.  It’d be a pain in the ass to fully flush the dex out to change its out for no benefit.

Edited July 14, 2021 by GTP091

[55trucker]

GM's dex-cool didn't come into existence until '95, early issues with it were related to the fluid acting on the gaskets produced at that time, corroding aluminum parts, plastic parts, clogging up the cooling system.

Personally I'd stay way from it with this old an engine. I've never been an advocate of *long-life* anti-freeze, use the regular Prestone, Peak, Zerex etc & replace it every 36 months....or...or as needed when tested with a antifreeze ph balance test strip. I NEVER purchase the 50/50, the concentrated is the way to go, mix it yourself, it will end up costing you less & don't use tap water, use de-ionized (soft water) bottled water. 

Edited July 12, 2021 by 55trucker

[Schurkey]

8 hours ago, 55trucker said:

GM's dex-cool didn't come into existence until '95, early issues with it were related to the fluid acting on the gaskets produced at that time, corroding aluminum parts, plastic parts, clogging up the cooling system.

Yup.  And I'm thinking that the formulation of both the coolant and the gaskets has been improved since then.

Quote

or as needed when tested with a antifreeze ph balance test strip.

NEVER purchase the 50/50, the concentrated is the way to go, mix it yourself, it will end up costing you less & don't use tap water, use de-ionized (soft water) bottled water. 

Also "Yup".  But beware that test strips may/may not be accurate with long-life coolant formulations.  They also have a certain shelf-life; they can age-out and become inaccurate.  I learned all of this the hard way.

Premix coolant--the "50/50" stuff--is little more than a consumer cheat.  I mix the full-strength stuff with distilled water.  And I generally mix it "stronger" than 50/50 in my climate.  Back before "Global Warming" made substantial improvements around here, I went as strong as 70/30.

Don't forget to pull the block drains after flushing.  In general, there's a block drain hole for each bank of cylinders.  GM usually installed steel/iron plugs that rusted in place, became difficult to remove.  I replace them with brass plugs, (or brass draincocks on vehicles I own.)  But in the "computer" era, one or both plugs may be a pipe-threaded knock sensor instead.  Sometimes there's so much rust in the water jacket that it forms a crust around the plug, no coolant drains out until you poke a Phillips screwdriver or awl through the deposits.

"Regular" coolant is supposed to be usable for two years of service life.  In my experience it's good for considerably longer than that.  The "Extended Life" stuff is supposedly good for 5 years (sometimes more) and again my experience is that it's good for much longer than that.  In both cases, this assumes that there's no reason to suspect that the coolant is being contaminated with combustion blow-by, or deliberately mixed with improper cooling system additives; the in-radiator transmission cooler isn't leaking, etc.

Edited July 13, 2021 by Schurkey

[White93z34]

Huh, this is a completely different conversation then I was expecting. Nice.

I can't really speak to the yellow HOAT stuff aside of I think my Ranger takes it.

I'm a big advocate of modern coolants and I operate under basically unless the cooling system has copper in it then run a better coolant then Green.

Obviously this isn't without its caveats and YMMV. You run the risk of upsetting the apple cart of marginal (or incompatible) gaskets. marginal water pumps etc

When I get around to regasketing the L98 I have on a stand and dump it in my Camaro I'll convert the car to dexcool at that time.

I ran green in my Seville for a time (that is another story for another day itself) but going back to back the dexcool is a superior coolant for that car.

[GTP091]

It’s had dex cool in it since I got the car in 01’.  I’ve read lots of ‘stories’ about dex cool and the issues that supposedly comes from it, as usual;  a lack of maintenance?  I change it every 3 years no matter what, considering i only drive in the summer and put on maybe 1500-2000kms a year I’m sure it’s not causing any gaskets to get eaten. Just can’t find any solid info on if the yellow universal stuff is even better. Seems from what I’ve read the yellow stuff is made for dummies so they can add it to anything without gumming up the rad. Dex was ran in corvettes from 96 and up so if it’s good enough for those engines I’m sure it’s fine for my LQ1. Dex cool it is!  Didn’t really want to flush 10 litres of distilled through to change it over anyway.
 

Tap water!? Wouldn’t even use that in wife’s daily.  Cat piss wouldn’t be much worse lol.

Edited July 14, 2021 by GTP091

[55trucker]

Aaaaaah.......the engine is no stranger to the fluid, well, if it's run sufficiently well & you've found no side effects then you've answered your own question,

 

by the way, how'd the exhaust turn out?

[Addicted To Boost]

I have run the yellow (which now appears to have a greenish tint?) long life Prestone stuff from Wally World in every w-body I've owned with no ill-effects.  Even converted a couple of Deathcool cars to it, and the system stayed clean thereafter. +1 for buying full strength and using distilled water.

[mfewtrail]

4 hours ago, Addicted To Boost said:

I have run the yellow (which now appears to have a greenish tint?) long life Prestone stuff from Wally World in every w-body I've owned with no ill-effects.  Even converted a couple of Deathcool cars to it, and the system stayed clean thereafter. +1 for buying full strength and using distilled water.

The yellow all makes/all models is basically the same formulation as Dexcool without the licensing for what it's worth.

[GTP091]

17 hours ago, mfewtrail said:

The yellow all makes/all models is basically the same formulation as Dexcool without the licensing for what it's worth.

Sounds about right.  I found acdelco dex at my local lordco I and am in the process of swapping it out today.  The old looks really good still so happy with that. Fighting a few hose changes as I go.  I opted out of the flush chemicals, just can’t bring myself to dump nasty ‘deposit eaters’ in the engine.

Edited July 15, 2021 by GTP091