Changing Dexcool Too Soon?

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Hi Everyone,

I'm interested to know if I should bother changing my Dexcool after 30,000 miles and two and a half years after it was last changed? I'm sure it's fine, but I was thinking about doing it strictly to extend the life of the cooling system.
 
It is sooner than needed, but won't hurt anything. Be prepared for responses saying not to refill with Dexcool because it is evil and will eat your engine from the inside out.
 
I have heard that before, but I chalked it up to an old wives tale amongst old-timer mechanics from back when Dexcool was first introduced and cars maybe had other problems or idiots mixed it with green coolant.
 
Someplace I read that some of the newer chemistries leave a passivating layer on materials, and so they shouldn't be disrupted. i think that was related to one of the G12 or G12+/++ variants, not entirely sure...

But IMO you can't go wrong replacing the inhibitors, so long as you don't mind the work. Personally, Id probably let it go another year or so before changing, but I doubt you're doing any harm...
 
I change the Dex in my cars that have a wet intake every 30,000 along with the cap. You won't hurt it.
Your car has a wet intake.
 
I just drain the coolant from the rad and then re-fresh with new every 3-4 yrs..no problem with dex from havoline...
 
Originally Posted By: Aurora09
I have heard that before, but I chalked it up to an old wives tale amongst old-timer mechanics from back when Dexcool was first introduced and cars maybe had other problems or idiots mixed it with green coolant.


I think you hit the nail on the head.

1) other problems
2) people mixing/running very low levels
 
Originally Posted By: cchase
Originally Posted By: Aurora09
I have heard that before, but I chalked it up to an old wives tale amongst old-timer mechanics from back when Dexcool was first introduced and cars maybe had other problems or idiots mixed it with green coolant.


I think you hit the nail on the head.

1) other problems
2) people mixing/running very low levels


More than likely. We routinely run ours until a component fails, and on the newer V8's we run that is a LONG time even in 3500 series vans.

Thank goodness some of the Dex myth is finally dying out a bit. But I still get quite a bit of stuff every time I defend it...
 
Originally Posted By: Aurora09
Hi Everyone,

I'm interested to know if I should bother changing my Dexcool after 30,000 miles and two and a half years after it was last changed? I'm sure it's fine, but I was thinking about doing it strictly to extend the life of the cooling system.


Spend your money on some Christmas presents. Let it go to 60K or 5 years assuming it looked clean.

The only issue with Dexcool is when air gets into the system on a continuous basis. That can be gaskets failing, or radiator cap failing or using Dexcool in a vehicle where it was not designed for it.
 
Originally Posted By: JHZR2
Someplace I read that some of the newer chemistries leave a passivating layer on materials, and so they shouldn't be disrupted. i think that was related to one of the G12 or G12+/++ variants, not entirely sure...

But IMO you can't go wrong replacing the inhibitors, so long as you don't mind the work. Personally, Id probably let it go another year or so before changing, but I doubt you're doing any harm...


I believe all coolants leave a layer on the cooling system materials for protection. Thats why cavitation is bad as it can rip off the layer and now its an issue as to how long before the layer is back again to prevent corrosion.
 
Originally Posted By: yonyon
Are you sure? I thought all Northstars had a dry intake.


I read Olds Alero! DOH!
 
A couple things; yes maybe I'll let it go until I find some rebates on dexcool. Also, the radiator and cap was changed summer 2011 along with new coolant which was about 30,000 miles ago. I have seen some write ups on the oldsmobile forums about "flushing" the cooling system using one of those kits that splice into the heater hose. I'm leery of that because my hose water is well water which isn't very good, and someone suggested using prestone super flush or some such thing, but I understand from my mechanic that this stuff is particularly corrosive. All I really want to do is drain it, refill with Kinetico filtered or distilled water and cycle that thru a few times, drain and refill(s) until it is clear. The thermostat seems fine, so that would be a job to do if I eventually need to replace the water pump. Does anyone here bother with the "flush kit" or "radiator super flush" or any of that?
 
I don't use the super flush. I have in the past used the "Flush Kit", but I had a clogged heat corp.

I just do a drain and fill on my wet intake cars.

You are fine for a bit.
 
I'm ignorant about this. What is a dry and wet intake, difference between the two? The car has a reservoir with cap, but there is no "cap" on the radiator itself.
 
So you should have a pressurized overflow.

Dry intake no oil or coolant touches it or runs through it.

Wet intake oil from the lifter valley touches it and coolant runs through it.
 
ls1Mike isn't telling you not to flush. He even said he does flush himself.

I disagree. You're planning to replace your coolant at a fairly short interval. If you drain and fill you'll be maintaining the fluid condition well enough with room to spare. Flushing is more work. Flushing also increases the amount of waste fluid you have to dispose of. When you flush there's a possibility you'll make an error with your math (okay, you probably won't) and end up with a bad glycol/water ratio.

Cavitation is what happens when your pump is spinning too fast for the coolant mix, pressure, and temperature you're running. The impeller spins too fast for the liquid to keep up creating a void where vapor forms. This is about as healthy for a water pump impeller as detonation is healthy for a piston. Realistically, it's not something you're anywhere near having to worry about if your cap maintains pressure. Your PCM already has a built in rev limiter and you are planning to use a suitable coolant mix.
 
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