Hey guys,

Got a few quick questions...

What process do you use to flush out the coolent in your car? I've heard a few different things over the last few days and i want to do it right.

most said to just drain it with the plug, and fill it up with tap water, let it run with the heater on and then drain it till it's clear.... but some say you need to pop the freeze plugs and back wash the rad. Now im hearing to get the kit to add a funnel to the upper rad line and use that to flush it out. So now im confused on the best way to clear out the system.

On another note, i picked up some Dex Cool since that's all that was at the local parts store and i figured it better then the green stuff. How much liquid does the stock 3rd gen cooling system hold? i want a 50% coolent to water ratio and was told 4 gallons is total so 2 gal.s of coolent and 2 gal's of water. Tap or Distilled???


sorry for my ignorance, i never really paid attention to flushing out the coolent when my car was in the shop.

Thanks,
Opha

 

I used to see kits that you could plumb to your heater hose in order to hook up a garden hose to help flush your cooling system. The only problem I see is, what do you do with all that old coolant? Up until recently I worked for a shop that did all the different flushes, so I did all mine there.
If you are going to convert to the Dexcool, then I would make sure to flush all the old. Sometimes the green and dexcool don't mix well, causing sludge.
Need to know what year, and engine size to know coolant capacity. That is, if I ever find my Chilton's manual (damn kids...)

 

Typical capacity for a 3rd gen is 17qts. - i.e 4 gallons.

 

Stay away from Dex Cool like the plague. Dex Cool is the most horrible worthless coolant in the world. At my old job I did a lot of coolant flushes. I saw atleast 10 cars that had Dex Cool in them. Dex Cool turns to sludge and will ruin your whole cooling system.

Don't believe me?

Search google for Dex Cool lawsuit.

 

FWIW, there seems to be a split regarding Dex-Cool. Some people hate it and some haven't had any trouble. From what I've gathered, if you don't properly maintian the cooling system while using Dex-Cool, problems can occur. Also, most of the complaints I have read online seem to involve certain GM trucks and SUVs. The problem may not be so much with the coolant as it is the construction of the vehicle.

It's worth mentioning that you can have problems with the "green" coolant as well. Green coolant is prone to developing scale in the system AND any aluminum parts will be more susceptible to electrolisis.

I have been using Prestone "Dex-Cool approved" coolant in my car for a while now and haven't had any trouble. I do keep an eye on it and ALWAYS use distilled water along with Redline Water Wetter.

Back in '96, 3 years after buying my car (and using green coolant), my intake manifold died as a result of electrolisis. Ate it up like cancer. At that time, I had to take it to the dealer to be repaired and it cost me a total of $1,000 to have the manifiold replaced.

In addition, I used to have an '86 Cadillac with the 4.1L V8 engine back in the days before Dex-Cool existed. This motor had aluminum heads and it was REQUIRED to add these small pellets to the cooling system anytime it was drained. This was to protect the cylinder heads from damage. So, technically, I could argue a case against "green" coolant.

Finally, if there is such a problem with Dex-Cool, then why in the world is just about every coolant manufacturer still making and selling the stuff? I mean, it wouldn't be wise for say Prestone to continue to make and sell a defective product.

Instead, it seems to me that it would be to their benefit to make a better product and then promote it by saying Dex-Cool sucks, ours is better so buy our product. With close to 40 million cars on the road currently using Dex-Cool, that would make for a nice profit.

 

Obviously you haven't seen what Dex Cool can do to your cooling system. I've seen multiple cases of it. It's not because of not having service done to your vehicle, because most of the cases I saw where the Dex Cool turned to mud it was under the mileage Dex Cool claimed to be good till. It's not just in trucks and SUVS either.


If Dex Cool is so good, then why is there a major lawsuit on them?

 

Well, I won't say that it's "so good", but I also haven't read any specific reason or details as to why Dex-Cool is "so bad". I'd also be lying if I didn't admit that there is some concern in the back of my mind, but I guess I'd lust like to have more detailed information other than "I had a problem, therefore I want to sue someone".

No one has come out and said Dex-Cool contains ingredient "X", which can turn to sludge when exposed to such-and-such. As a tech, do you have any information you could share?

As far as the lawsuit, remember the big 20/20 episode where they trashed GM trucks as being rolling bombs? "Get in an accident and your GM truck will explode because the gas tank design and position is bad."

It wasn't long after that it was exposed that 20/20 rigged the truck in their video to explode for a nice scary visual effect. While it was probably true that a small number of trucks had caught fire, it was no where near as bad as 20/20 made it out to be.

Still, a big lawsuit got filed and lots of GM owners saught money even though they never had a problem. I still see a lot of those trucks on the road today.

 

If that is the car you are working on...Chilton's lists coolant capacity as 9.1 qts w/ A/C and 8.8 qts w/o A/C.

 

I honestly don't know the chemical properties that cause it to turn to sludge. Where I used to work they had an article all about it for customers to read. I thought it was a crock of **** just to get a few dollars. But when I finally saw what Dex Cool can do, I believed it. The first time I saw Dex Cool sludged up, the car hadn't even had 75,000 miles on it, the coolant literally looked like a foamy chocolate milk with clumps of garbage in it.

 

I've been doing a bit of online reading regarding Dex-Cool and some auto experts recommend changing Dex-Cool every 2 years or 30,000 miles, just like traditional coolant. It seems the claim that it will last 5yrs/150,000 miles is proving to be untrue and that it breaks down much sooner.

Others have suggested that any leak that allows air into the system can cause the sludging to occur. I currently also own a '96 Cadillac that has always had Dex-Cool in it. The coolant tank does have a nice brown coating inside of it and the heater has gone out twice in the last 2 years. Heater core was replaced last year and it failed again this year.

It very well may be time to ditch the Dex-Cool based on what I'm starting to see and the info. I have read. I found this at AllData.com:

and this: