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?
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 degree(stat)/psi(cap).
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.