Jeffvette

Aurora40

I know a lack of coolant system maintenance is a cause of headgasket problems on older Northstars. I had wondered if LT5's experienced the same problems, but in reading around it seems rare for people to have any internal problems with these motors.

I missed your pre-edit post though, so I apologize if I'm talking out of my ***.

MrCrowley

I haven't worked on many northstars so I can't relate to them. However I have expecienced lots of issues with dexcool with corroding. I wouldn't ever recommend it in ANY car much less an lt5. It looks like the lt5 head gasket material is not compatable with dexcool.
Here is a great topic about what Gm has done with dexcool. Hope this sheds some light on the subject.
http://forums.corvetteforum.com/show...es&forum_id=34

Here is some issues I have found with lt5 gaskets and dexcool. Much more swelling and deterioration from dexcool.
http://eesvette.hyperboards.com/inde...t=0#1134530480

DDSLT5

I looked at those pics. I agree that it seems like the dexcool has caused the gasket material to degrade, and that is enough evidence for me to avoid the use of that material. I'm confused though - how did the metal ring blow out? If I didn't know better, I'd guess it was a nitrous failure of sorts, from a casual glance. Does the dexcool degrade the metal of the engine as well? Did it somehow weaken this metal ring? If yes, then how did it blow out? Some sort of detonation?

Do you think it was like this before or did this occur while cleaning the throttle body with the carb cleaner? It just seems like it would take quite a bit of combustion chamber pressure to blow out that ring.

Don't mistake my curiosity for sarcasm - this problem intrigues me - I'm curious as to how such a catastrophic failure could be caused by the coolant, and if so, what other metallurgical failures could one similarily expect from having that coolant in place?

Lastly - when did they make this crap standard use? Aren't all C5s equipped with it? Tell me more about other failures you've seen - any LSx motors? I have a C5 - what should I watch out for? Now you've got me worried.

90 Corvette ZR-1

i'm going with too much n20

Trizney

Where did the pics go?

I am pretty sure you are only suppose to use Dexcool when the car came equipped with it. I am pretty sure this started in 1996, maybe 1997.

Both Dexcool and the normal green stuff are ethylene glycol based antifreezes, but Dexcool has different corrosion inhibitors. Those different inhibitors when mixed or diluted is what I believe causes most of the problems. If you keep the Dexcool at the proper mixture, and change it when it needs to be changed you shouldn't have issues. When the rust inhibitors brake down, well, you know what happens.

Trey

MrCrowley

Dexcool never cam in a 91 zr1, and nitrous has never been on this car. When the gasket failed the car wasn't even moving! I think dexcool didn't come into play until 94.

Doc,
I would pull the thermostat on a vehicle and flush until completely gone then refill with the good ole green stuff. That's just my opinion. I have seen many of domino affects from dexcool too.

On one vehicle off the top of my head; it went through 2 radiators, then the water pump, then heater core, and last but not least it was eating away and begin to rot out freeze plugs.

Zproud

Question about the global antifreeze?

should we stay away from that too?

tomtom72

Sorry for being so unknowing but I have to ask. The green stuff is what should be in a early Z? and the red stuff should be in a later Z?

The local chevy dealer said to use either on in my 90? The car is asleep for the winter & I don't mind tossing the coolant & flushing before vette season starts. I just don't want to cause motor problems. I tried to buy anti-freeze from the dealer using the spec # listed in the owners manual & they said the stuff in the C5/ C6 is what I should use. I let them do the flush & refill & they used the red stuff.

After seeing this I just want to know if I made a big mistake, I'd rather throw out coolant than do motor work.
Thanks!
Tom

DDSLT5

Get rid of the red crap - put the green stuff in the LT5!

BERTZR1

I work on cars everyday,I have seen dex-cool do some amazing
damage to coolant parts and head gaskets.On One occasion it was
1998 dodge Caravan it took out A water pump impeller.
I would stay away as far as I can.




AL.

Z Factor

The article listed in this linked thread might be of interest to some of you on this subject.

http://www.zr1netregistry.com/forum/...read.php?t=994

ZRWON

If you want to really know the history and misleading actions by GM and Texaco including the resulting 8+ class action suits do a GOOGLE.COM search for dexcool problems, or class action suits, etc. Your heart will skip a beat or two. Here's my horror story:
My '98 Cad fell apart at ~70K miles which I feel (but couldn't prove) was all caused by Dexcool. I am now a member of one of the DEXCOOL class action suits.
I spent over $1200 with dealers who tried to fix the over heating with their final failure resulting in diagonosis that I needed to replace the motor ($5999+) because the head had warped from overheating and pulled the headbolt out of the block thus it couldn't be repaired. How they knew this is beyond me as they hadn't even pulled the valve covers. I then stuck another GM dealer with that dog by trading it in on a new GM car.
Cadillac never admitted any wrong doings or responsibilities, but because I raised so much HEl@ the Cad marketing group did give me a $2000 GM loyality certificate good for purchase of ANY GM car. I subtracted the $2000 AFTER finalizing my negotiations on the best deal I could make with the dealer. With that $2000 certificate and all the other discounting GM was doing in late 2004, I couldn't afford NOT to buy another GM car.
The new car does have DEXCOOL in it but I purchased the GM Extented Warranty from CF member Ken Fichtner: kenfichtner@fichtnerchevrolet.com who was >$1000 less than the local dealers were trying to stick me with for the same GM plan.
My advice: Never use DEXCOOL or if you have it in your car make sure you have the extended GM warranty to cover the damage it WILL CAUSE you at some future date!
Sorry this is so long: really hope it'll prevent others from going thru a costly mess like mine

Aurora40

Just FYI, but the early Northstars didn't have Dex-Cool either. They were less tolerant of lax coolant system maintenance I guess.

It is hard to buy traditional silicated coolants now. Wal-Mart no longer carries any, they carry Prestone's Extended-Life/All-Models coolant. It is basically Dex-Cool with a yellow coloring. I am interested in the Zerex G-05 (I think that's the designation) coolant, though silicated green stuff is probably the safe play.

I'd think if you wanted to play around with it, you could just put some gaskets in a bucket of Dex-Cool and see what happens instead of trying it on a working motor.

TommyL

A little off topic.......I was looking at purchasing a Pontiac Montana for the wife to drive in the winter and did some reaserch.
The Pontiac Montana and the Chevrolet Venture are two vehicles well known for head gasket problems. I am wondering now if perhaps this coolent maybe the cause, seems they all have this problem in time. I looked at about 10-2003s, 2004s and out of 10 half had the head gaskets replaced with only 50-70,000 kms.

DDSLT5

Ahhhhh damn! So - riddle me this: is it really that hard to get the regular green coolant? If the answer is yes, I'm going to go and STOCK UP!!!

ittlfly

And to add to the confusion.....I went to buy the "green stuff" for my 92 and the ONLY thing I found was the Prestone's green color that will go in ANY vehicle that is "currently on the road"........all that according to Prestone. So what's up with that if it will mix with anything out there (red or green)? the only tihng good about it is that it was green in color so I did the 50/50 mix (distilled), closed my eyes and went ahead with the coolant change.

Aurora40

From what I understand, this is basically the same as their Dex-Cool formula. Dex-Cool can mix with other coolants too, it just won't have the long-life property anymore.

Like I said, it's hard to find silicated green coolant anymore. At least around me. But it looks like Prestone at least is convinced enough to take the gamble and tout their stuff as being safe for all cars.

93RubyZ

I guess I haven't been paying much attention to anti-freeze types over the years, so I did a seach on Google for DexCool. It's interesting to see the trend in titles of the topics that pop up...

MrCrowley

From what I see the gasket from the dexcool gasket has swelled up more than double the thickness of the head gasket. Noing I don't like dexcool I would recommend not mixing them for sure. I'm pretty sure 93 and earlier z's came with the green stuff. I would never in my life convert it to red!

I only use the green traditional antifreeze, and if your dealer converted you over I would get rid of it asap.