Thread: Dont use Dex Cool if you don't do the maintenance.

Found this in the Junk Yard engine I am using. If the car hadn't been smashed it would have been overheated to death. only 52k on the engine everything else was spotless.

Happens when sitting exposed to air

^that^ Dex cool is "ok" but once it is exposed to atmosphere it goes down hill.

strawberry chocolate milkshake???

Originally Posted by dsmuts

Happens when sitting exposed to air

would 30 days cause that? that's how long the car sat before I got the engine...

The biggest reason why Dexcool fails is due to user error. The service interval clearly states 150000 miles....OR 5 YEARS, which ever comes first. Most people ignore or don't notice the 5 years part. That would mean every single Gen II w-body should have had the coolant/antifreeze drained and refilled AT LEAST twice by now, if not 3 times. How many of you have even done it ONCE? The problem with Dexcool is if it's not changed on time, it becomes acidic a lot faster than the "normal" green coolant, thus why all these gasket failures take place. Yes, it was the Dexcool eating away at them, but there's a pretty good chance it wouldn't have happened if the coolant was changed on time.

Also, you absolutely can not mix the "normal" green coolant with the Dexcool, and I'm sure there are a lot of people out there that go to top off with the green coolant because they don't realize their car came with "the orange stuff", or don't care because the green stuff is cheaper/"it's all the same". When the 2 mix, the chemical reaction causes the coolant to gel up and clog the passages, pretty much like what your pictures show. It would not surprise me at all if that was mixed at some point.

I'm not saying it's "good stuff". I still think they should have left the "normal" coolant alone. In fact, I still suggest that people doing a LIM gasket completely and thoroughly flush out their cooling system and switch to the green stuff. I'm just saying a lot of the failures are due more so to people not following directions than "Dexcool sucks".

Raregmfan did u mean 5 years not 5 months at the beginning of ur post where its bolded

^^ what he said. if we had to change it every 5 months than it would have been more than 3 times lol

Yea lol. Although to be honest I flush my coolant myself yearly. I have all my vehicles.

I was going to say. Who puts on over 150,000mi in 5 months?! lol

personally i just put the green "normal" coolant in it. Unless it has dexcool in there

A yearly dex flush should be the norm by now for all 3800s. Some people don't get it.

Neglect or issues cause that and I am not sure if the most current formula of Dex would do that.

What year was this vehicle?

Originally Posted by BillBoost37

Neglect or issues cause that and I am not sure if the most current formula of Dex would do that.

What year was this vehicle?

Late 2005 so according to the info I found out today, this car was over due for cooling maintenance.

So you are suggesting people don't use Dex based on a car that didn't get maintenance per the manual for them?

Yup.. somehow I don't agree with your post about how bad this crap is... or maybe it's because the majority of cars don't have this issue. My truck is a 2000..I finally changed it's coolant at er ... like 11 years old and it was perfectly fine.

Originally Posted by BillBoost37

So you are suggesting people don't use Dex based on a car that didn't get maintenance per the manual for them?

Yup.. somehow I don't agree with your post about how bad this crap is... or maybe it's because the majority of cars don't have this issue. My truck is a 2000..I finally changed it's coolant at er ... like 11 years old and it was perfectly fine.

Yes, well I was under the impression that Dex was maintenance free and upon reading the reply from RareGmFan I learned that it does in fact need maintenance every 5 years or 150k. I personally don't use it And the first thing I did to my car in 2009 when it was purchased was flush out the Dex and poured in a 50/50 mix of green. This is from personal experience as I saw my moms 2001 GTP with 10k on it gum up in 2002 and need an entire flush and front head gasket.

Sorry, guys. Didn't get much sleep last night and I posted that right before I was about to take an apparently much needed nap, but yeah, as most people figured out, obviously I meant 5 years. I do somewhat fault the makers of Dexcool and GM for their marketing tactics. They were trying to get as much acceptance as possible for their new, environmental friendly, biodegradable product by pushing it as low maintenance. That's why most people only know about the 150k mile maintenance interval part, IF they even know THAT vs. it's a "no maintenance" coolant. Unless you've seen the sticker somewhere under the hood of your car, there was no real mention made of the 5 year part.

Oh, ironically, the reason I didn't get much sleep last night is I was up till pretty late doing the water pump on my car. This is the 2nd time I've had to replace it in 5 years, but the Dexcool that came out (about a gallon's worth) was nice and clean. No discoloration, no chunks or sludge, nothing. Even the old water pump was clean, and this is despite the fact that I've completely neglected the cooling system in this car. The upper and lower radiator hoses are so old and weak that they're collapsing on themselves, and the 2 WP changes is the closest that it's come to a flush and fill. Car now has 177k miles on the original motor, trans and s/c.

Collapsing hoses is a sign of a bad rad cap

Never had any issues with dexcool personally.... but I take care of my crap so *shrugs*

From what I have herd is that dexcool is much much better at protecting aluminium then the "green stuff" (Aka silicate based coolant) .... I have also been told that basically all modern coolants nowadays use OAT instead of silicates anyways so basically everything is dexcool reguardless of color.