DirtyBirdMKE

i need to flush and clean my cooling system and im wondering what is the best way to do so and if there is some special product i can use to get and the crap out of the enging and radiator

RPM WS6

iTrader: (3)

LS6427 has done some excellent write-ups on the process for a comprehensive cooling system flush for neglected or contaminated cooling systems. If you search this topic under his user name, you will find it.

LS6427

iTrader: (2)

^^^Thanks man......


"DirtyBirdMKE"

Here you go. My coolant system flush write-up and my power steering coolant system flush and fluid replacement is in there too.

https://ls1tech.com/forums/general-m...g+system+flush

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DirtyBirdMKE

neat.... thanks

great421

iTrader: (1)

OP -

Very good write-up by LS6 427 - my step-father (a GM Tech) gave me the same basic set of instructions years ago.

I'd only add that once your car is 100% free of Dexcool, put in standard green coolant - not universal coolant (i.e. - "Safely mixes with all colours!"), but rather old-school Polyethylene Glycol. (FYI - I found mine most recently at o'reilly's auto parts.)

Yes, yes - I know, this topic will cause a number of individuals to rail on both sides of the issue (to Dexcool or not to Dexcool) - so let me offer one additional perspective:

I had a radiator shop owner (who was also an ASE certified master mechanic) tell me a number of horror stories about Dexcool when it gets old and oxidizes; it begins to solidify.

Long short short - I flushed my good / new Dexcool out completely, put Green coolant in and my LT1's temps dropped 10-15 degrees.

I know that I only offer anecdotal evidence, so do your own research.

Just my $0.02...

Good luck!

LS6427

iTrader: (2)

True.. go green stuff. My brand new engine just got Dexcool put in by the shop that installed it......but I'm gonna flush it and go green in a few months when I have time.

Green does run cooler.

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RPM WS6

iTrader: (3)

I've never had a bad experience that could be blamed on Dexcool in an LS1 engine, and that's after nearly 15 years and 4 different LS1s.

The trick, like with anything else, is just to maintain the system properly:

- Don't leave your Dexcool in for ~10 years or 130k miles like some people have. Drain/refill the system every year or two, or do a full flush every 3-4 years.

- Don't allow excessive amounts of air to mix into the system, such as running the system low. Lots of air mixed in for long periods will not go well with Dexcool.

- Use distilled water (or pre-mixed coolant) rather than tap water to dillute the Dexcool. This may or may not be necessary depending on the source/quality of your home water supply, but it's a pratice I have always followed since it's the OEM spec.

I've followed these basic principles in all of my LS1s with nothing short of excellent results. My '98 still has a 100% original cooling system (even gaskets, radiator cap and hoses), and there is not one leak, the engine temps stay perfectly between the t-stat temp and custom programmed fan temps, and the inside of the radiator is very clean. In fact, I just drained and refilled it last weekend, and everything looked great - no sand/sludge/slime nor anything else unpleasant was found.

Also, keep in mind that there is no magic to the old green coolant. It too will harm cooling system components if allowed to age long enough without proper maintenance. Many of us that have owned older cars that came with "green" coolant have had to deal with destroyed/leaking heater cores and radiators thanks to improper cooling system maintenance.

It's not that "green" coolant is bad or good, nor that Dexcool is bad or good; pick whatever you like, maintain the system properly, and you'll be rewarded with issue-free operation for a very long time. Just don't expect either option to be some sort of magic bullet that you can put in and forget about for a decade without any ill side-effects.

LS6427

iTrader: (2)

Yup.....I've never had even a hint of trouble from Dexcool. But over the past 10 years or so a LOT of guys locally here have changed to the green stuff. Almost all of them report better cooling. Especially a few Vette guys, which run hotter than our FBodys.

I'm gonna just do it. It is cleaner than Dexcool and if I can run 5-10 degrees cooler like all these people that would be a bonus.....

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Atrus_SS

iTrader: (1)

Just curious - why do people say to stay away from the universal "yellow" stuff?

LS6427

iTrader: (2)

If by "yellow" you mean the orange Dexcool..........

Dexcool works perfectly.......IF you have a perfectly sealed cooling system and ALL of the air is bled out of the system.

If it leaks or you have a radiator cap that's not sealed well.....or you have a leaking water pump for two weeks and you're driving it around......the Dexcool gets all sludgy and crappy. It gets thick and the flow slows down and then you have inefficiency of its cooling ability.

The Green stuff will never get like that even if your system isn't perfectly sealed.

I didn't pull the factory stock engine out of my 1998 Trans Am until 2002 when my 427ci went in. My cooling system was never opened for those first approximate 4 years. My Dexcool was clean like NEW after 4 years.

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Atrus_SS

iTrader: (1)

Nah, I mean the "universal" stuff mentioned in an earlier post. Can be mixed with either Dexcool or the Green with no issues.

LS6427

iTrader: (2)

Ive never heard of a universal fluid.

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Atrus_SS

iTrader: (1)

I've seen it - it's usually more yellow in color.

LS6427

iTrader: (2)

This whole cooling "fluid" issue has become like choosing an oil, or spark plugs, or spark plug wires.

Bottom line: for our engines, the LSx engine, which is nothing more than an every day, normal V8....... Anything will work perfectly and none of the brands will work better than the other.
Until someone starts building a badass engine with forged internals with specific clearances......with high power.......it just doesn't matter what is used.

For coolant.......Dexcool and Green both work perfectly.......as long as the system is SEALED and completely topped off with NO air in the system.

Personally, in the hot climate I live in, I use just half jug of Dexcool and the rest hose water. 14+ years and my coolant is always perfectly clean.

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great421

iTrader: (1)

One (small) point of order:

Polyethylene Glycol has a higher coefficient of thermal conductivity than Dexcool; which is why (with all other factors being equal) a Dexcool-equipped car will run about 10 degrees F hotter than a car using Polyethylene Glycol.

In the same way that R-12 is more thermally efficient than R-134a, Polyethylene Glycol is more thermally efficient than Dexcool.

Yes, a properly maintained cooling system will work fine with either Polyethylene Glycol -or- Dexcool, but once Oxygen / air mixes with Dexcool, all bets are off.

IMHO:
Polyethylene Glycol is more forgiving, and moves more heat, but it does indeed require more maintenance; unlike Dexcool which (as its main selling point) you can simply leave in the vehicle for X number of years as long an the cooling system remains 100% sealed.

Having said all that, I hope our OP (or anyone else for that matter) isn't too worked up about this "Tempest in a Teapot".

: )

777Shock777

iTrader: (5)

I'm honored to have been the noob who asked the question for such great information