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00' Silver/Blk STS
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Discussion Starter #1
What is the reliability factor on HG's on a 2000 STS?
Are they just as susceptible as any others?

Mine is a 00' with 112000 on it. (Very well taken care of)
No problems (yet, knock on wood), previous history from the Caddy dealer says it had water pump and several other things done at 57k. I just recently had coolant changed again, for preventative reasons, along with P/S and Brake sys flush and a pressure test all checked out good and passed with flying colors.
I'm concerned about one thing and one thing only......The dreaded HG

In your humble opinion do you think that the previous history and what I have done along with taking care of it will decrease my chances of having a HG failure?
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Don't get paranoid. Enjoy the car, drive it like you stole it, keep it clean and maintained. If a tire blows, the transmission hiccups, or the engine dies, it's no different from any other automobile or mechanical item on this planet: nothing is perpetual motion. The litany of automobile problems over the years is carefully overlooked for the blame of the moment. Admittedly, with a Cadillac Seville/Deville/Eldorado FWD platform the price of admission can be quite high. If that's a true factor in your case, buy a Camry.

Ol' Destroyer will chug in here at any minute with his condemnation of all things Northstar, but he conveniently neglects mentioning faults with anything else around.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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Sub I'd rather push a Caddy than drive a Camry...lol.....unless you plan on installing one of your 455s in it for me!:thumbsup:

The probability on the 2000+ depends on the coolant maintenance. If the dex is still in there, get rid of it, fast. Hopefully it has at least been changed periodically. On 2000+, It's more common for the HG's to corrode away than the bolts to pull. Dex is the cause of this, so get rid of the orange stuff. Once the inner core of the gasket rusts away, there's nothing left for the bolts to clamp down on.
 

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White Diamond '03 DHS (with DTS floor shift)
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I have kept the Dex in every one of my Northstars and have yet to have a HG problem. I hate to disagree with Jake, but I just don't buy that. Just don't leave it in the forever. It needs to be changed. Maybe sooner than the factory recommendation. It can't hurt to error on the safe side.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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Ranger you're unlike many car owners- you maintain your car religiously. You won't allow Dex to sit in there & get corrosive.

One of these days I'll post pics of some HGs in my collection. From seeing 65+ Northstars I've concluded:

engines that have/had green coolant had the best HGs- no corrosion, just the normal depressions and raised areas around the cylinders (open coolant jackets)
engines that have Dex have HGs that are rusted to sh*t around the coolant jackets
some HGs that had Dex aren't as bad as others. Some are really rusted. I think this varies according to how often the coolant has been changed

I tore an engine down about a month ago, from a '93 Allante. Original HGs, green coolant from the factory, best HGs I've ever seen. The engine had been swapped due to oil consumption. None of the aluminum surfaces had corrosion or pitting. Some engines that have had dex have had very bad pitting, especially on the water crossover & ports on the block/heads. I've seen a few other N*s that were run on green coolant and the HGs were consistently in better condition.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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I don't want to disagree with Ranger either but there is something about the Dexcool that is allowing the inner core of the head gaskets to rust away. I think it is only as the Dex gets older but it could start soon after the factory fills the cooling system. The rate of corrosion could be dependant on the composition of the metal gasket core and the formulation of the dexcool, and this could vary car by car. 65 engines is 130 HGs, and, while there will never be hard proof, there is something with the Dex. After I saw the HGs from that 93 Allante, I started using green coolant on all customers cars and I'll be switching on my own this summer as well.
 

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White Diamond '03 DHS (with DTS floor shift)
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Dammit Jake, you make some good points. I think I may stay with Dex, but I'm going to 2 year changes. Screw this 5 year stuff.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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Good idea Ranger, coolant is cheap and any longer than 2 years is too long. I tell all of my customers, $40 worth of coolant is a lot better than another HG job, so every two years, change the coolant. At least go with the Prestone brand Dex, steer away from GM's formulation. It's GM approved so it can't be any worse. I still trust the Prestone brand.
 

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'98 ETC Black 90k miles
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Yeah, that's my plan too. I had my coolant changed after I bought the car last August - wanted to know the last time it was done, and I wanted to have it run with new coolant for a while and get it tested to combustion byproducts. Thankfully the test came back negative after two hours of hard driving. However, I had our local Cadillac dealership do it, and they used Dex. I'm going to let it run this summer with the Dex, and if I decide to store it again this winter I'll change it to the green stuff beforehand. Or, if I end up calling Jake for a pre-emptive HG job, then it'll happen at that time.

As to the OP, every car is a gamble. Every gamble is different. On N* cars, either the DexCool engine coolant or the HGs/block happen to be a weakness, and every now and then they blow. On a long enough timeline, every factory HGs time will run out. Do what I did - start saving up money. I don't even really have a coordinated way of doing it - I popped $600 in a separate account to start 'er off (actually about three days before I purchased the car - I came here and did my homework first) and just tossed in $5, $10, $20, and $50 as the mood struck me. I can afford the HG job now, but I also have a few other things I'm eyeing first (like this, and this, and this, and this). However, I'm going to make sure that whatever I buy, I keep a hard floor of money in my account for when/if the day arrives.
 

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1999 Cadillac DeVille
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279 Posts
so have we come to a conclusion that prestone dex approved coolant is less corrosive than GM dex or is it just as? I have seen mixed reviews, I still plan to change my coolant every 2 years no matter the conclusion but I would just like to know exactly what I am putting in my car.

Thanks guys :thumbsup:
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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I am to be perfectly honest, not sure if the Prestone stuff is any better. But Prestone is the #1 name in coolant and I'm hoping they did there chemistry work when they came up with the formula.
 

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2005 Deville Base, 2004 Escalade AWD
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If any member has it I'd like more info on the Dex chemical composition as it relates to "becoming corrosive". Certainly there is a correlation between a coolant's lifespan inside the system and its ability to continue providing the same protection - but at what point does it begin eating away at the gaskets? Is there a supposed curve? Other factors to coolant longevity would include unnecessary opening of the system allowing contaminants to be introduced which is why on the very rare occasion I take my vehicle to a "we service any make / model" type of oil change / tire shop I make it a point to see they do not top off any of my fluids with whatever they may have in the bay at the time. I changed (drain, fill) my coolant this past weekend and the purged coolant mirrored the new coolant - I filled two glasses side-by-side and they looked exactly the same - very clean to the point I was tempted to add ice and drink the stuff. I'm guessing that most of the coolant breakdown can't be identified visually but "dirty" coolant or excessive crap around the cap would be an early indicator of a problem. Either way I'm changing the coolant every year as part of spring maintenance - I spent around $13 at Wally for the concentrated Dex and a gallon of deionized water. It's one of the cheapest PMs you can do for the car. :thumbsup:
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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For the truly inquisitive wrencher, there has to be a test kit out there somewhere which will measure the Ph and O2 content of a coolant.

Just as with oil analysis, you test the brand new stuff to form a base line, then you test every 6 months to determine which way the Ph (alkaline < > acid) is going and what the O2 reads.

When the coolant tips toward acidity, get it out of the engine.
 

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I am to be perfectly honest, not sure if the Prestone stuff is any better. But Prestone is the #1 name in coolant and I'm hoping they did there chemistry work when they came up with the formula.
In order to put the name DEXCOOL on a cooling system product, a company must be licensed by GM and the product must meet GM6277M specifications.

As of May, 2006, there were fewer than 10 companies licensed; among them are Chevron, Prestone, Shell, and Valvoline.

It is all the same stuff. Just like Coca-Cola bottled in California is exactly the same as Coca-Cola bottled in Atlanta.
 

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White Diamond '03 DHS (with DTS floor shift)
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I was thinking about this again an as always I come back to the same question. IF Dex is the cause of the HG failure, why do all other GM engines not suffer the same problem?
 

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1992 eldorado. 2007 dodge magnum hemi r/t
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I don't want to disagree with Ranger either but there is something about the Dexcool that is allowing the inner core of the head gaskets to rust away. I think it is only as the Dex gets older but it could start soon after the factory fills the cooling system. The rate of corrosion could be dependant on the composition of the metal gasket core and the formulation of the dexcool, and this could vary car by car. 65 engines is 130 HGs, and, while there will never be hard proof, there is something with the Dex. After I saw the HGs from that 93 Allante, I started using green coolant on all customers cars and I'll be switching on my own this summer as well.
This is good to know,good timing,I was going to change the antifreeze in my 97 sts soon,
I was going to ask if there is something in dexcool that is not in the green stuff to cause this aciditic action,I have already bought the dex so will probably use it,
Does anyone know why there was the switch to dexcool in the first place?.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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I was thinking about this again an as always I come back to the same question. IF Dex is the cause of the HG failure, why do all other GM engines not suffer the same problem?
Ranger the 3.5 Aurora/Intrigue engines are experiencing the same problems. It's a newer engine- started in 1999 so the HG issues are just beginning to surface like the Northstars have for a while now. Again, it's aluminum.

3800's have the very odd failure, as well as the Vortec 4.3's and the Vortec V8s.

I believe the aluminum has some sort of reation with the Dex. I can't explain why the Dex rusts away the HGs, all I know is that it does. Pics coming soon.
 

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Did we ever come to a consensus on when the headgasket issue was resolved? I'm buying a 2000-2005 deville and am wondering if there is any difference in regards to the headgaskets?
 

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1999 Cadillac DeVille
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So the way I am reading this is as long as the coolant is changed often enough (every 2 years) we should not have a problem no matter what color coolant we use?

Or am I way off base here?

Thanks again guys.
 

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IMHO you should use the green stuff but yes, Dex should be alright if you change it at least every two years. Just from what I've seen, I'm ditching Dex altogether.

Even '04's are starting to have HG failures. They should be very, very rare though. It's a hit and miss deal I believe with the newer ones.
 
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