Did the TB bypass and 160 degree T-Stat mod today on my 89 coupe. After removing the TB I noticed a rusty looking crud on the coolant jacket torgue tip screws heads. I was lucky that none of the screws broke during removal. The Dex-Cool had wicked its way through out the entire TB coolant jacket gasket. The gasket was like mush. I could see where coolant seepage had entered the IAC chamber and on the lower TB gasket as well. There was no indications, such as poor engine performance, this was happening.
With the bypass in place and a new TB gasket set installed, this will not happen again.
I like Dex-Cool. My engine runs 10 to 15 degrees cooler with this stuff but I can not stop wondering how the other gaskets in the cooling system are holding up?

 

I've heard that dex cool and play hell with gaskets and water pump seals that originally used the green stuff.

When I switched my 92 over to dex cool I had replaced all the gaskets and the water pump anyway. So far so good.

 

Thanks I'll keep a eye on my water pump seal. FYI, I removed the TB last June for a good cleaning at which time I installed all new TB gaskets. In the fall I flushed out all the green stuff and refilled the cooling system with Dex-Cool. Didn't take long for the orange stuff to show its true colors.

 

switching from conventional coolant to extended life( dex cool, t.e.l.c., etc) is a big no no. when these 2 coolants meet they form a type of acid. it deteriorates gaskets and eats rubber like crazy. we have had many problems with this in the diesel industry.. well, we have had major problems with extended life coolants period. im loving the job security.

 

When converting from green to orange, you have to get all the green out, which usually means flushing the block, thoroughly!!!

I hadn't considered green-soaked gaskets though - you learn something every day.

 

I have switched to dex cool in a number of cars and never had any problems ,92 olds achieva scx with a quad 4, 94 camaro with a3.4l v6, 94 mercury grand marquis witha 4.6l v8 ,and my 90 vette :chevy

 

I also changed from green to Dex in both my 85 and 88. Never had any cooling problems.I also never used any chemical flush.

 

I have a dexcool question , why does it make the engine run cooler? on the stewart water pump site they claim nothing is better than water with some water pump lubricant added. I know most of us have to run antifreeze coolant because of weather reasons, but have we got other opinions on this, Im just curious what the chemical reason is, dexcool is designed for aluminum head engines, and it has all of these fancy ratings and approvals from different companys. So what do you guys think ?

 

Do NOT use Dex-Cool in systems designed for glycol
(the green stuff), Dex-Cool attacks radiators (and
heater cores) assembled with lead solder. Also, its
inhibitors are inadequate for the needs of glycol
systems. Especially do not mix Dex-Cool and glycol
coolants (here's a thought: just how many flushes
does it take to ensure none of the old coolant remains ?)

Do NOT use water by itself as a coolant, especially not
tap water.

DO use distilled water as a mix with glycol - get 3
gallons from the pharmacy section of your supermarket
and drink what you do not use. That's distilled water (not
mineral water). You want to reduce or eliminate the
minerals commonly present in tap water because they
precipitate out to create scale and corrosion.

DO follow instructions by mixing at a ratio of 50:50 glycol:water.
This gives increased boil protection and ensures there is
sufficient quantities of the inhibitors/lubricators you want.
If over-heating is an issue, add a quantity of WaterWetter
from Redline.

DO flush and refill the cooling system with fresh glycol:water
every two years.

If you have aluminum heads, DO search this site for threads
describing the problems with corrosion leading to head gasket
failure and, in several cases, engines ruined by coolant that
leaked into the oil pan.

As for why a system might become more effective when
Dex-Cool has been added - I do not know. Dex-Cool is referred
to as an organic acid technology (OAT) coolant, maybe it scours
the scale off of the innards and enables better thermal conduction?
Maybe just the act of flushing the system improved efficiency and
the engine would have run cooler with water:glycol, too?




[Modified by Slalom4me, 2:55 PM 4/27/2003]

 

Thank you, that is very good information,it sounds like the good old green stuf is the way to go. I recently had a bad experience with my 96 buick with a 3.1 v6 , the intake manifold started leaking after about 50k miles it uses dexcool sounds like I need to change it every 2yrs instead of 5 yrs.Im currently overhauling my 85 vette and I was considering dex cool but now I think I will stick with the green stuff.

 

I don't know why anyone would *want* to switch from good old green to the odd ball orange stuff anyhow. If you want to pump up the cooling power of green, just add a bottle of Redline Water Wetter or similar product during flush and fill procedure.


[Modified by Lone Ranger, 5:06 PM 4/27/2003]

 

TOTALLY AGREE with Slalom4me. Very Good Advice. :thumbs: :yesnod:

 

50/50 = how many gallons of each?

I am about to fire up my new motor in 2-3 weeks and would like to mix it right from the get go!.

What about watter wetter?

 

Some mechanics I know are switching back to the other, Its causing problems. Espically if it isn't changed often.

 

Sounds like you got gaskets that were not Dex-compatable.
Were they Genuine GM parts for a Dex-cool car?
Remember, everything in the system has to work together.
Don't blame the Dex-cool if the gasket was not designed to work with Dex.

Larry
code5coupe
:seeya

 

Sounds like you got gaskets that were not Dex-compatable.
Were they Genuine GM parts for a Dex-cool car?
Remember, everything in the system has to work together.
Don't blame the Dex-cool if the gasket was not designed to work with Dex.
My philosophy is this: don't put anything in your engine that the manual doesn't tell you to use. Fewer headaches that way....

Larry
code5coupe
:seeya

 

It is for the cars that came with it.


Without more info, I would not draw conclusions from a manifold gasket
failure in a car designed to use Dex-Cool. Also, one of the aims of
Dex-Cool is/was longer service intervals between flushes. When I wrote
about flushing every two years, I was referring to water:glycol systems

This ought to work out well for you.

 

To answer your question as to why anyone would want to use Dex- it contains no silicates which are very abrasive and wear out the water pump seals. Water pumps should last much longer with Dex.
Before I switched to Dex in my 85 Vette I called Havaline(sp?) and asked if it would harm anything. They said as long as I got all the gren anti-freeze out it would work fine. I have been using it in the 85 for about 7 or 8 years ( whenever it came out I forget the exact year) , change it every 2 years( with distilled water) and had no problems. I have been using it in the 88 for 3 years with no problem. When I change the anti-freeze in both cars I can see the radiator fins inside the rad. are clean and shiney.

 

If you have a 1989 with a completely empty, stock
cooling system, then the capacity is 3-1/2 gal in the US
(13.3 L everywhere else on the planet.) If you have
another year, check the manual for your year. If you
have a modified system or have flushed the system
(and still have coolant in the heater core ect.) then
you may need more or less than the quantity the
factory specs indicate.

Therefore, to get a 50:50 mix in a stock 1989, 1-3/4 gal
water needs to be mixed with 1-3/4 gal of glycol (6.6 L
ea for the metric among us).

Filling the system with the desired ratio will go more
easily if you plan ahead and premix at one or more
gallons. At the start you can pour in a gallon each
of distilled water and of glycol. However, as the
system begins to fill, air-locks will need to be bled
out and if you are trying to add a little of one followed
by a little of an other at this point, it is easy to lose
track. If you have a container of both already
premixed, then you can just pour it in as required,
knowing that it will be right. (The technique is also
useful after flushing because how much coolant
still remains in the system is hard to know.)

Do not obsess about getting an exact 50:50 ratio, this
the ideal but nothing will be compromised if you are off
a little either way (unless you really need -35 F protection
and wind up only having -28 F protection ).

BTW, an antifreeze tester (looks like a battery
hydrometer) only costs a few bucks at parts stores.

If you don't have cooling problems, save your money.

If you do have modest cooling issues and you have
already taken care of the obvious maintenance and have
ruled out signs of impending doom, then read the instructions
and use it. Otherwise, spend your money on fixing the
problems instead of throwing it at the symptoms.

Best of luck with the engine project !





[Modified by Slalom4me, 8:39 AM 4/28/2003]

 

Thought I'd throw this one in as well:-
What about the GM cooling system additive? Those tablets are a little odd don't you think? I have used them, but don't know if they did anything. I was told they're suppposed to stop minor leaks. :steering:


[Modified by Davemc1963-87conv, 10:17 AM 4/28/2003]