why i love Dexcool, summed up in one picture

pulled the knocking 4.3 out of my recently acquired '01 Blazer and started pulling it apart to see what was wrong... the #1 rod bearing spun, scoring the hell out of the crank journal and big end of the rod... so i figured since it was on the stand and i might rebuild it, i'd pull the rest of the motor apart because why the hell not, right, and found this when i pulled the heads off:

there are supposed to be 3/16" or so holes in there where that gunk is, but both of them were completely clogged on one head and one was clogged on the other. looks like it wasn't getting much circulation thru there to me.. also, all the water jackets in the heads, block, and intake manifold are coated with orange sludge. i imagine the heater core being about the same, but the radiator looks to be a newer replacement and looks good inside from what i can see..

yeah, i know: this is probably a result of improper maintenance, but the truck has 120,000 miles on it and GM swears up and down that this stuff is 100,000 mile durable. i've never seen anything remotely like this on an older engine that used the good old generic green coolant...

Ha, I did read here that GM had taken Dexcool to court for making an inferior product.

Internet rumor I've read is that orange coolant is great, as long as it stays orange. Meaning, an ill-informed owner doesn't mix in green coolant, creating the sludge from the blend.

Mmmmmm. Fudge.

If I become a dubstep DJ, my stage name will be Dexcool.

The early Northstars had some atrocious head gaskets issues that were attributed to Dexcool. I believe that was part of the court appearance Mr_Clutch42 referenced. Not only does this stuff suck as coolant, it smells absolutely foul as well. And being a GM tech, I come into contact with it frequently.

RealMiniParker wrote: Internet rumor I've read is that orange coolant is great, as long as it stays orange. Meaning, an ill-informed owner doesn't mix in green coolant, creating the sludge from the blend.

Partially correct. The other issue is that Dexcool will react with other things- like, air, I think- so having a fully bled (i.e. never low) cooling system is critical, too. I have seen that other automakers have started using the Orange Death (OD) so its possible they've worked out some of the issues. But on older cars- yeah, stay away from the crap. My wife's 2000 Jimmy has had just about every component of the cooling system replaced, and the engine flushed, and the coolant still turns brown.

100k miles my arse, do it every 30 or 40 like with the green stuff.

I got money back from GM in the class action lawsuit over this......probably explains why they went after dexcool.

Wasn't one of the other big issues that Dexcool is supposed to be pressurized at all times to work right, but GM just went ahead and tossed it in a bunch of vented cooling systems?

I'm a big fan of Zerex G-05, myself.

After all the horror stories I've heard about Dexcool, I have to wonder what alleged advantages it had over other products.

A few years back I encountered a 4.3 vortech in a forklift that had bad dexcool. The water pump mounting points were rotted away from the inside of the block.

That was hard to explain to the customer.

Duke wrote: After all the horror stories I've heard about Dexcool, I have to wonder what alleged advantages it had over other products.

I believe it was supposed to have longer life (5 years/150K miles). I never run it in my own stuff. Even though GM says not to use the green stuff I've yet to have a problem. Kinda like how people swear you have to use the special Honda coolant but I never did in my Acura and it was just fine.

I have an 04 Suburban with 150k miles(I bought it with 117k 3+ years ago) that has Dexcool in it of course. Should I be draining this stuff today?

In reply to Mazdax605:

I would certainly be looking at a flush and fill. That's about the end of the service life. The world may not end tomorrow if you don't do it, but it's certainly cheap insurance to change it out...

SlickDizzy wrote: In reply to Mazdax605: I would certainly be looking at a flush and fill. That's about the end of the service life. The world may not end tomorrow if you don't do it, but it's certainly cheap insurance to change it out...

I have no idea how long the coolant has been in there. Maybe it was done just before I acquired it, but maybe not. I guess I will add this to the list of things to do. Should I replace it with more Dexcool? I'm sure I won't be able to get all of it out, so is that an issue with mixing if I don't choose to replace it like for like?

Mazdax605 wrote: I have an 04 Suburban with 150k miles(I bought it with 117k 3+ years ago) that has Dexcool in it of course. Should I be draining this stuff today?

Just be careful- as mentioned above, Dexcool doesn't play nice with the other types of coolant, so flush it out really well and replace with Dexcool, bleed the system and make sure it's full.

In reply to Mazdax605:

If you aren't 100% positive you have all of the old stuff out of the system, only put more Dexcool in. You're asking for serious trouble if you don't. That said, it is really not that hard/expensive to do a complete flush.

In your shoes I would go the extra mile, flush it completely, and change over to some phosphate-free G-05 goodness. All of the major manufacturers are running some variation of it these days and I am told it is about as "universal" as modern coolant can be.

SlickDizzy wrote: In reply to Mazdax605: If you aren't 100% positive you have all of the old stuff out of the system

I've never had problems using the new universal coolant after draining the dexcool out of the many trucks I've had. And these are trucks with over 400,000kms on them.

NickD wrote: The early Northstars had some atrocious head gaskets issues that were attributed to Dexcool. I believe that was part of the court appearance Mr_Clutch42 referenced. Not only does this stuff suck as coolant, it smells absolutely foul as well. And being a GM tech, I come into contact with it frequently.

good to hear from you … I've a new ('14) Sonic 1.4T 6MT … when can I switch out from Dexcool ? should I switch ?

I assume a complete flush and then switch ?

Yeah if youve never seen it, Orange+green=mud. I mean it literally looks liked you filled the radiator with wet mud. This is all part of "Nobody does maintenance any more, we should make everything maintenance free." So theres this, and theres no grease zerks on your steering linkage, and there are trannys with no dipstick, sealed for life bearings, etc, etc,

Don't mix it with air, as I watch it puke into the overflow tank...that's half filled with air.

RealMiniParker wrote: Internet rumor I've read is that orange coolant is great, as long as it stays orange. Meaning, an ill-informed owner doesn't mix in green coolant, creating the sludge from the blend.

Yes, but only with the silicated "old school green", the modern silicate free "mixes with everything" stuff that is often dyed green, and most modern OE coolants, are basically improved dex cool, very similar chemistry.

Looks like what the water jackets look like when an intake gasket leak is ignored and the coolant gets aerated/oil gets sucked in.

From: https://en.wikipedia.org/wiki/Antifreeze

DEX-COOL specifically has caused controversy. Litigation has linked it with intake manifold gasket failures in General Motors' (GM's) 3.1L and 3.4L engines, and with other failures in 3.8L and 4.3L engines. One of the anti-corrosion components presented as sodium or Potassium 2-ethylhexanoate and ethylhexanoic acid is incompatible with nylon 6,6 and silicone rubber, and is a known plasticizer. Class action lawsuits were registered in several states, and in Canada,[21] 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.[22] Late in March 2008, GM agreed to compensate complainants in the remaining 49 states.[23] GM (Motors Liquidation Company) filed for bankruptcy in 2009, which tied up the outstanding claims until a court determines who gets paid.[24]

It really is terrible stuff.

for sure it WAS … is it still ? and if so why does GM still use it ? and I'll ask again, do I flush and switch as soon as I run out of warranty ?