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Dirty coolant dipstick (yellow sludge)

VFSSBlackLS3

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I have done a search on this but can't seem to find anything consistent on it...
Basically when I check the radiator cap, the coolant is clean, red, and consistently full... But Today I was doing weekly check on fluids and other things. I checked the coolant dipstick and found it was coated in a yellowish sludge that completely covered the markings on the dipstick!
My mates with LS2 VEs reckon they get it too but I cant seem to see anything about it online.
Is it actually normal for Gen4s to do this?

My engine is the 6.2ltr LS3... Everything looks, seems and runs perfect, apart from seeing this.

Is it something to do with the stuff in the coolant? Can anyone confirm if this is normal and part of the LS2,LS3s nature?
 

Skylarking

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Was curious so read up a little about long life coolants here. This indicates GM uses an organic acid technology (OAT) coolant known as DexCool within their vehicles.

Variants of OAT coolant, including DexCool in some instances, have/are also been/being used by other manufacturers.

To quote the article, “All DexCool-approved coolants to date use two organic acid rust/corrosion inhibitors, one called sebacate, the other called 2-EHA (which stands for 2-ethylhexanoic acid). These organic acids are very stable and last a long time, although they take thousands of miles to become fully effective in protecting coolant passages”.

The other interesting bit is “The inhibitor 2-EHA poses another issue: It's a plasticizer (softens plastic), so it has been blamed for coolant passage gasket leakage. Softening (and the resulting distortion) was reported by Ford, which encountered gasket leakage problems when it tested a DexCool-type formula on its V8 engines”.

Then there is the issue of mixing different types of coolants during top up which can possibly increasing corrosion within the cooling system (not so good).

All this makes for a rather interesting subject which I’d love to know more about.

So to answer your question, with some speculation as I’m no expert, it may be the DexCool used in our LS3s results in the plastic overflow tank and plastic dipstick going a little gooey over time while the rest of the system suffers small leaks as Ford found out... the yellow sludge is dissolved and deposited plastic (which doesn’t sound ideal)...

I don’t know what was wrong with the old coolants that were replaced every 2 years as they always worked well in my cast iron block, alloy head, copper & alloy radiator vehicles without issue... as long as they were frequently flushed and replenished... Progress for the lazy I guess....
 

VFSSBlackLS3

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Thank you for that, there's some clarity I needed to see! The main question I have then, is what is the best coolant to run in the Gen4 V8s that may prevent this from occurring
 

panhead

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I have an LS2 which by the way is a HSV only engine in Australia and I haven’t encountered this problem.

I'll now have a look into it in case I've missed something.





.
 

426Cuda

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Was curious so read up a little about long life coolants here. This indicates GM uses an organic acid technology (OAT) coolant known as DexCool within their vehicles.

Variants of OAT coolant, including DexCool in some instances, have/are also been/being used by other manufacturers.

To quote the article, “All DexCool-approved coolants to date use two organic acid rust/corrosion inhibitors, one called sebacate, the other called 2-EHA (which stands for 2-ethylhexanoic acid). These organic acids are very stable and last a long time, although they take thousands of miles to become fully effective in protecting coolant passages”.

The other interesting bit is “The inhibitor 2-EHA poses another issue: It's a plasticizer (softens plastic), so it has been blamed for coolant passage gasket leakage. Softening (and the resulting distortion) was reported by Ford, which encountered gasket leakage problems when it tested a DexCool-type formula on its V8 engines”.

Then there is the issue of mixing different types of coolants during top up which can possibly increasing corrosion within the cooling system (not so good).

All this makes for a rather interesting subject which I’d love to know more about.

So to answer your question, with some speculation as I’m no expert, it may be the DexCool used in our LS3s results in the plastic overflow tank and plastic dipstick going a little gooey over time while the rest of the system suffers small leaks as Ford found out... the yellow sludge is dissolved and deposited plastic (which doesn’t sound ideal)...

I don’t know what was wrong with the old coolants that were replaced every 2 years as they always worked well in my cast iron block, alloy head, copper & alloy radiator vehicles without issue... as long as they were frequently flushed and replenished... Progress for the lazy I guess....
Thanks. Very interesting!
 

immortality

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Was curious so read up a little about long life coolants here. This indicates GM uses an organic acid technology (OAT) coolant known as DexCool within their vehicles.

Variants of OAT coolant, including DexCool in some instances, have/are also been/being used by other manufacturers.

To quote the article, “All DexCool-approved coolants to date use two organic acid rust/corrosion inhibitors, one called sebacate, the other called 2-EHA (which stands for 2-ethylhexanoic acid). These organic acids are very stable and last a long time, although they take thousands of miles to become fully effective in protecting coolant passages”.

The other interesting bit is “The inhibitor 2-EHA poses another issue: It's a plasticizer (softens plastic), so it has been blamed for coolant passage gasket leakage. Softening (and the resulting distortion) was reported by Ford, which encountered gasket leakage problems when it tested a DexCool-type formula on its V8 engines”.

Then there is the issue of mixing different types of coolants during top up which can possibly increasing corrosion within the cooling system (not so good).

All this makes for a rather interesting subject which I’d love to know more about.

So to answer your question, with some speculation as I’m no expert, it may be the DexCool used in our LS3s results in the plastic overflow tank and plastic dipstick going a little gooey over time while the rest of the system suffers small leaks as Ford found out... the yellow sludge is dissolved and deposited plastic (which doesn’t sound ideal)...

I don’t know what was wrong with the old coolants that were replaced every 2 years as they always worked well in my cast iron block, alloy head, copper & alloy radiator vehicles without issue... as long as they were frequently flushed and replenished... Progress for the lazy I guess....
I do believe there is or was a court case about this, i.e GM been sued by it's customers....
 

VFSSBlackLS3

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I have an LS2 which by the way is a HSV only engine in Australia and I haven’t encountered this problem.

I'll now have a look into it in case I've missed something.





.
Do you use DexCool?
 

Skylarking

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I do believe there is or was a court case about this, i.e GM been sued by it's customers....
Interesting.

Going further down the google rabbit hole, it seems the 2008 DexCool class action settlement and the 2009 chapter 11 bankruptcy protection GMfiles shafts impacted GM customers. Yep, GM agreed with the courts to settle for $150m at $50 to $800 per impacted customer but via the bankruptcy got away with only paying out an estimated 30%... I’m sure the executives got a bonus out of this mess :(

This DexCool issue being “resolved” in 2008, the more relevant question is whether our cars will develope some issue or did GM/H learn and change their coolent formulation?

[edired to add following]
My VF2 owners manual states to use DexCool conforming to GM6277M but I have no idea what formulation this is and whether it is still problematic. The 2003 version of this GM spec was supposedly last updated in 2012 but it’s only available for a price as far as I have found.
 
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immortality

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Yep, that was it, bloody hell time has passed quick...

The GM "bankruptcy" didn't just **** the customers, it also fucked a lot of their staff retirement benefits etc.
 

Ron Burgundy

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More likely transmission fluid mixing with the coolant in the radiator...
 
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