Dex cool, yay or nay?

**homickb** · 11-25-2010, 07:12 AM

I went to check my anti-freeze levels and found some white chunky s*** that had clumped together in my coolant. Because of this, I'm planning a complete flush of my radiator. I've heard that dex cool creates problems for the engine, would there be any problems if I just cleared it all out and used complete anti-freeze?

**zeetwentyeight** · 11-25-2010, 07:35 AM

Originally Posted by homickb

I went to check my anti-freeze levels and found some white chunky s*** that had clumped together in my coolant. Because of this, I'm planning a complete flush of my radiator. I've heard that dex cool creates problems for the engine, would there be any problems if I just cleared it all out and used complete anti-freeze?

You would still want a 50/50 though
Were you located at?

**Firebirdjones** · 11-25-2010, 11:18 AM

I think where people run into problems is letting the system go for 5 years or more because the coolant says you can.

I don't follow that maintainance schedule, I flush mine every year and I simply don't have a problem with either Dex Cool or the standard Prestone stuff.

With that said, what you use is really up to you. Sounds like it needs a good flush anyway, and from there you can use what ever you like. If you make a change to standard antifreeze, I'd make sure to use one that says it mixes with all types, just in case you don't get all the Dex Cool out, and you probably won't get it all. It'll take a couple of flushes and changes to be certain.

**Z28_Driver** · 11-25-2010, 11:28 AM

both orange and green coolant varieties work.
like said...just don't mix unless compatible.
the dexcool eats gaskets may be true, but head gaskets blow in old cars too.

**Firebirdjones** · 11-25-2010, 11:33 AM

Yep, keep in mind all antifreeze gets corrosive if left in the system too long. Especially very hard on aluminum parts.
Regular change intervals are your friend.

**pajeff02** · 11-25-2010, 11:46 AM

Dexcool here and no problems. Note that the service manual advises against utilizing a chemical flush in our cars. You'll want to drop the block drains as part of the flushing process as there is quite a bit of coolant retained in the engine. Also, don't forget to clean out your overflow tank.

**importssuck** · 11-27-2010, 05:38 AM

Where are the block drains located on the block?

**pajeff02** · 11-27-2010, 05:42 AM

There is a 17mm allen head behind and above the alternator on the driver side. The passenger side drain is above the starter and even though it is probably metric, a 5/16" allen head seemed to fit best.

**homickb** · 11-28-2010, 05:42 PM

I live in windsor, ontario. And I believe that it has been quite a while since it has been changed, if ever. I bought the car in june from the original owner who had only put 70000 kms on it, and I'm sure that it was neglected quite a bit during its life.
But anyway, from this I'm gathering that I should change it immediately, and that I don't need to do a complete system flush or that I don't need to switch from the dex cool. But still, I want to be as safe as possible with this car, as I definitely know that I don't want a blown head gasket
So that said, is antifreeze better?

**pajeff02** · 11-29-2010, 07:33 PM

Originally Posted by homickb

I live in windsor, ontario. And I believe that it has been quite a while since it has been changed, if ever. I bought the car in june from the original owner who had only put 70000 kms on it, and I'm sure that it was neglected quite a bit during its life.
But anyway, from this I'm gathering that I should change it immediately, and that I don't need to do a complete system flush or that I don't need to switch from the dex cool. But still, I want to be as safe as possible with this car, as I definitely know that I don't want a blown head gasket
So that said, is antifreeze better?

You should flush the entire cooling system, however, the manual recommends against utilizing a chemical flushing agent. I just ran clean water through mine to force out the old coolant. For the best results, the block drains should be removed during the flushing process. Change out the thermostat and hoses while you are at it.

Dexcool is fine.

**JayTA98** · 11-30-2010, 07:48 PM

not to steal the thread but whats the correct way to flush the whole system besides using a shop flushing machine? i mean is there a kit or something that we use with a water hose? Thanks.

**pajeff02** · 12-01-2010, 03:09 AM

I dropped all the coolant, removed the thermostat from the housing, re-installed the empty housing, and then filled the system with straight water. I then ran the car for several minutes with the heater on "hot" and held the rpm's up a bit towards the end before shutting it down. After the engine cooled off, I dropped all the water out and repeated this process until the water coming out ran clear. It might have been 3-4 times total that I did this. Then, with all the drains open and the radiator and heater hoses removed, I put the garden hose to it and flushed everything out manually for a few minutes, including the heater core.

**Smittro** · 12-01-2010, 05:38 AM

I would'nt.. I changed back to old green after hearing horror stories.. I flush mine on a regular basis and this is STILL what I found when I pulled my upper and lower intake.. Bottom ones are the old ones top is the new.. This was after dex cool.. Up to you.. Just my .02.

**Demon_Z28** · 12-01-2010, 08:56 PM

I have changed my coolant so many times in the last year from two cam swaps and head swaps. But on my Z28 when i had it at the time, i rarely ever changed it and my coolant looked beautiful. I make sure to use distilled water as tap water has mineral deposits that can build up in the system. i have yet to have issues with dex-cool as I remember years ago GM had a bad batch of dex cool that was eating rubber seals. I don't think there is any major issue with this anymore though.

**JoshuaGrooms83** · 12-02-2010, 12:36 PM

The dexcool issue was more for GM 3 series motors with the Intake manifold gasket issue. (Ask me how i know... i dare you lol) I stay away from dexcool. But in our cars its not as bad as the rest of the GM line up. Whatever you do DONT believe the "life of the vehicle" line. Our car have a recommendation of I believe 60K for coolant exchanges. Id have to read the manual again. but a safe bet is like an annual thing with green stuff. I would do a Flush that pushes the old stuff out along with a cleaner agent that get old gunk out and then replaces everything with brand spankin new fluids. Thats how i did my car after it turned over 100K. Afterworking in a shop for a couple of years, we had alot of GM 3 series motors coming in for coolant flushes and gasket replacments due to the generals poor design and i started getting paranoid about it so i went green (so to speak lol)

**99'CajunFirehawk157** · 12-04-2010, 07:29 PM

This falls into a coke or pepsi debate, IMHO

I've used DEX and have'nt had any issues in 3 yrs, had the intake off too, but IMHO flush anything regularly!

This debates gets heavy over at bob is the oil guy forums too.

**pajeff02** · 12-05-2010, 05:00 AM

Originally Posted by 99'CajunFirehawk157

This falls into a coke or pepsi debate, IMHO

I've used DEX and have'nt had any issues in 3 yrs, had the intake off too, but IMHO flush anything regularly!

This debates gets heavy over at bob is the oil guy forums too.

FWIW, the intakes on our cars do not have a coolant crossover like prior GM V-8's. That's one reason that pulling the intake is not as much of a chore as it was in days gone by.

**Smittro** · 12-05-2010, 05:25 AM

Folks can use what they want really.. The post was added for a different perspective..
In 20+ years of working on verious types of engines running the "green" stuff I've never seen coolant corrosion like this on just gaskets..
Even on cars that have never seen a coolant flush..
The 60*v6's also suffer from the same gasket leak but only after the addition of the then new DEX cool

..
Which sould put a red light on for anyone with an engine running it..
Prior to DEX cool it was not an issue on either engine 60* iron head, nor early high features.
Nor was it an issue with the 3.8/3800 90* v6's series I-II-III which all are the same base engine..
Yeah it could be the addition of the plastic intake.
However I don't have a plastic intake and still had a leak and corroded rubber forms..
I'll stick with old tried and true poison little critter green stuff..

**KMdef9** · 12-05-2010, 07:45 AM

I changed mine after hearing from 2 different GM employee's, no need to get into which department they work for, but after they flushed all of their vehicles, I decided to do mine. This was long before I read anything on the net about it, as I did it the first week I owned the car.

From what I gather from reading many threads like this and talking to a few veteran oil/fluid change shops employee's, either way is fine as long as it gets changed on a regular basis, not in the frequency suggested by the manufacturer. But keep in mind, far fewer people have had a problem that was caused by typical green.

I have also heard, that aftermarket dexcool isn't the same as the head gasket blowing GM produced dexcool. But I have no way of confirming this other than it's "what I heard."

I'm not going to say green is WAY better than dexcool, but if your going to be doing a proper flush, I would change to green. Easier to find and even cheaper I believe.

**Hanzy347** · 12-05-2010, 10:14 AM

OP do you have the powersteering cooler in your car its the aluminum piece on the upper rad. hose? If you do they sometimes can leak powersteering fluid into your coolent sounds like what your white substance is. Somethin to lookout for!