I have a 2002 Chevy Impala with the 3.8 liter engine. I just turned
62,000 miles on it mostly of which is highway mileage.
I have an extended warranty until 82,000 miles and wanted to change my
Dexcool Antifreeze. Is this a good time to have it replaced? Should I
stick with Dexcool or go with some of the other brands out there?
(There is so much information against Dexcool as well as some positives
as long as it is changed more frequently than the 100,000 mile
interval). I was thinking of replacing it with Dexcool again since the
vehicle is still under warranty.
Can I adequately flush the system myself with the Prestone Flush Kits
or do I need to have a mechanic use a machine to ensure complete
flushing of the cooling system to include the engine block?
I have used the Prestone Flush and fill kits in the past but did not
know how effective it is with the 3.8 liter engine.
When I change the antifreeze, I plan to replace the Thermostat as well
as the radiator cap as I understand air can get into the dexcool thru
the radiator cap. (Does this sound reasonable?). Do I need to put in
more sealer tablets into the new antifreeze? How many and where are
they inserted? Put them in whole or cruch them up?
My father has a 2001 Lesabre with the 3.8 and wants to change his
antifreeze as well. These are some of his concerns as well as he has
had a leaking intake manifold.
Thanks In Advance
A complete drain and refill with Dexcool is a good idea. Personally I
either use pre-mixed 50/50 antifreeze or I mix with distilled water.
Why introduce minerals and other contaminants from your tap water? I
don't use the Prestone Flush kits because they rely on tap water.
Your system should be nice and clean at four years and 60k miles, so no
special flushing is really needed.
If you can get to the drain plugs on the block to drain it thoroughly
that would be good.
Prestone sells a premixed Dexcool which is what I would use. No worries
about getting the concentration right.
The way I read this is: you want to do proper cooling system
maintenance and you what to do it right! WTG!
I've always installed flush/fill kits in my cooling systems. If you
intend to use the 50/50 mix, remember you must compensate for any water
left in the block or you will not have the same degree of freeze
protection that is claimed on the jug (that may/may not be an issue
where you reside)
Make sure you replace the T-stat & R-cap with the correct
As far as antifreeze: I'd use the type recommended for the system....
I think this is a good preventative maintenance plan. If your extended
warranty is tied to DexCool,
then I would continue to use it, although I am not a great fan of this
product. (I would prefer HOAT
techology, at least).
Removing the thermostat can make it easier to flush through the block with a
garden hose. You can
usually flush both radiator and block with nothing more than a garden hose.
Disconnect the lower
radiator hose to allow it to flush until you get clear water. You dont have
to get anal about the flushing.
Unless the engine or radiator is badly fouled with iron oxide or such, just
wash everything out with water.
If you have block drains, etc, you may get a bit more sludge out of them.
You might want to flush through
the heater hoses to be sure you get the heater core clean as well.
Some will say there is no reason to replace the thermostat as long as the
old one is working, and that
is probably true. Do it if you feel better about it. Be sure you get the
new one (or the old one, if you
want to re-use it) back in the same way it came out. On some models you can
get them in upside down.
A new radiator cap is cheap, and is also not a bad preventative item.
If you see any indication that your radiator or heater hoses are getting
old, cracked, torn, etc,
this is as good a chance as you will ever have to replace them too.
Sometimes they last for years,
sometimes they dont.
As John mentioned, you can use distilled water cheaply enough when you
refill the system. In some
areas the water is plenty good, but in others it may be fit to drink but not
fit to put in your car. Using
distilled is not a bad idea.
You can mix the antifreeze accurately enough yourself. You dont need to buy
prediluted mix, unless
it just suits your fancy. This isnt rocket science.
Assemble everything back together carefully and fill with the coolant blend.
Remember you will
almost inevitably get some air trapped in the block and or heater core and
will need to be sure you
get the air displaced by the fresh coolant.
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