blown 87

Yep, no need for me to add to it, other than I wont use it in any of my cars.


I also remember GM saying there was nothing wrong with it in the first place.

I think, with nothing to back it up that Dex-cool is ok in cars that were filled with it from the factory, as long you it got changed every other year and never got mixed with any other coolant.

I have seen it not be very good when left in to long or mixed with even a trace of other coolant.

I use Porsche Blue in customers cars, and G-05/distilled water/water wetter in mine.

One thing I love/hate about G-05 is it leaves a very easy trail to see when it leaks and dries, the bad thing is it is a bitch to clean once it is dry.

Mike B

That's very similar information I've obtained...mixing Dexcool appears to be unhealthy.

I've had the "blue" stuff from VW / Porsche in my 951 for years...and happily recommend it. This forum gave me the heads up on Zerex (G-05) for the 928 and I use it and have no concerns.

I have no experience with cleaning spills with either coolant.

Glenn M

I will never use Dexcool! My 2001 GM minivan (80k miles) blew a head gasket due to corrosion caused by Dexcool. I had the heads skimmed, you should have seen how this stuff was jelled in the block. Of course the 3.4L motors are also notorious for intake leaks thank you very much. I had that replaces the summer before.

There is a big lawsuit with owners and GM/Dexcool. I missed out on the timeframe.

I would rather work on my 928 then that GM monkey puzzel!

I have a friend that replaces the Dexcool right after he buys the new car.

Cheers

jcorenman

Lucky Dog!!

Earl Gillstrom

Roger,

GM paid a lot of money to customers with engines destroyed by Dexcool.
It may have been reformulated and might be OK now.

But, I am not sure. Kevin Mccartney on the professional mechanics list is a great proponent of G05, so that is what I use. I have two GM vehicles that I have converted to G05 and they seem good.

I put Dexcool in one of my 928s years ago and saw gelling and switched to G05.

As I said, Dexcool may have been reformulated, so, may be OK now?

To be on the safe side, I also change AF every 2 years in all my vehicles.

I believe that failure to replace anti-freeze is the cause of blown head gaskets on 928s.

If you decide to replace the AF in your VAN, do a good flush first.

ROG100

Well that's good enough for me - no more Dex-cool for my cars.
I guess I will be doing a lot of flushing in my not to distant future.
As I always say I learn something new from you guys every day.

911tracker85

OK. returning the Dex-cool.

repeat question? if I get the Audi blue coolant will there be an issue if I did not get every last drop of the old AF/coolant out? I already have the hoses off and drained engine block too. with motor cold not sure if I tried to flush more if it would get all old stuff out.

Leon Speed

If I were you, I would use a garden hose with normal water to flush, then use distilled water to flush, then put in new coolant. Make sure to get the two drain plugs on the underside of the engine block. Btw when you last ran the engine did you turn the heater on and did you open the heater valve when draining the block?

GlenL

Please be aware that "Dex-Cool" is a formulation spec'd by GM that was made by havoline and Prestone, at least.

Wiki is always informative:

Organic acid technology

Certain cars are built with Organic Acid Technology (OAT) antifreeze (e.g., DEX-COOL[5]), or with a Hybrid Organic Acid Technology (HOAT) formulation (e.g., Zerex G-05[6]), both of which are claimed to have an extended service life of five years or 240,000 km (150,000 miles).

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in GM's 3.1L and 3.4L engines, and with other failures in 3.8L & 4.3L engines. Class action lawsuits were registered in several states, and in Canada,[7] to address some of these claims. The first of these to reach a decision was in Missouri where a settlement was announced early in December, 2007.[8] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.[9]

There are rumors that mixing DEX-COOL with standard green (non-OAT) coolant causes a chemical reaction that produces sludge in the cooling system. According to the DEX-COOL manufacturer, however, "mixing a 'green' [non-OAT] coolant with DEX-COOL reduces the batch’s change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine."[10]

According to internal GM documents, the ultimate culprit appears to be operating vehicles for long periods of time with low coolant levels. The low coolant is caused by pressure caps that fail in the open position. (The new caps and recovery bottles were introduced at the same time as DEX-COOL). This exposes hot engine components to air and vapors, causing corrosion and contamination of the coolant with iron oxide particles, which in turn can aggravate the pressure cap problem as contamination holds the caps open permanently.[11]

Typically OAT antifreeze contains an orange dye to differentiate it from the conventional glycol-based coolants (green or yellow). Some of the newer OAT coolants claim to be compatible with all types of OAT and glycol-based coolants; these are typically green or yellow in color (for a table of colors, see [4])

the flyin' scotsman

Not that I would add Dexcool to the 928 I do have it in my truck.

Bought new in '03 my chev 3/4 ton 4x4 with the duramax turbo diesel engine came with Dexcool and the owners manual states 5yr or 160k kms change interval. I had the coolant flushed/changed last Jan at over the 5yr and 180k kms for the first time and all was and remains well including -35c starts.

The Zerex coolant in the 928 has also performed without issue. All rubber hoses, t.stat and water bridge gaskets have been replaced as maintenance on 22yo parts but the rad and head gaskets are original.

M. Requin

This was at one time the consensus - at least among some of us - on the Jag XJ-40 forum as well. Old antifreeze does not protect against electrolytic aluminum corrosion, I believe.

TheoJ

I am with Aryan on the Glysantin G48 stuff. Good product.
Not sure if you people in the US have that in stores though.

Flushing is not even required but I would use distilled ater if I had too. It is not that expensive. Just need a large bin, hose and a pump to pressurise the fluid and run it through the system.

ROG100

Thanks to Greg I am going to flush 3 of my cars with the BG product to be safe and now have a source for the Zerex G-05. Selling for about $12.50 a jug.
See you can teach an "Old Dog" new tricks.

eatiles

were I live is always hot ( the carribean) can I just use distilled water and water wetter instead of coolant?? Thanks

hacker-pschorr

That is what a lot of track cars use since coolant is against the rules with some sanctioning bodies (doesn't evaporate and is very slippery)

Only issue is coolant also raises the boiling point, so maybe in your case 80/20 mix?