Hey Guys,

I currently own a 2005 Bonneville SLE, and of course running the Dexcool. I have heard many horror stories in the past about this Dexcool and how it eats away gaskets and caused the intake manifold to leak and the gasket needing to be replaced. Now I guess they have changed the formula of Dexcool, but still seems to be an issue.

I just recently purchased the car 2 months ago, and currently has 78000 miles on it, so chances are the damage is already done. But, i was considering doing a complete flush, and was wondering how easy this was to do, and what the capacity is? Should i even consider going a flush and going back to green antifreeze? Just wanting some input and thoughts!

Thanks guys,
Eric

the Dexcool thing is all a myth look here about it
https://www.gmforum.com/showthread.p...light=dex+myth

If you want to do a flush and use a different coolant, that'* fine, but not needed. DEXcool is perfectly safe in your engine. The problem with flushing it out is if you miss even a little it will sludge up. So flush really really good. I flushed 7 times to make sure it was clear. The only reason I removed the DEX and went to green was because I prefer the green color to identify the coolant by site.

If dex deteriorated the gaskets, then what deteriorated the gaskets (that have the same issues and failures) in pre Dex cars? This question has long made me wonder about many of the folks screaming about the tragedy of Dex.

I've found it to sludge if air is present and it is allowed to stay that way for a good amount of time. Beyond that, maintain it properly like all coolant and you won't have any "dex" issues.

Being 2010 with a 2005 car, you are definately in line for some maintenance. I would flush the system well and probably use one of the easier to find "Anycolor" coolants.

Hey Guys,

I really thank you for the feedback and input.

When i went to look at my car at the dealership, it had 74,500 miles on it, and when i opened the hood, the overflow tank for the Dexcool was VERY dirty looking. I opened the cap and put my finger insided to feel a really greasy, built up sludge inside the tank. It looked/felt like old soggy, moldy leaves. I asked the service guy about it (which they ended up replacing my tank) and he said it was common with the Dexcool. He showed me several other Impalas (2006+ with 50,000 miles on them) with the same issue. He didnt really have a good reason for why this happens.

My concern, is if this is happening within my overflow tank, i can only imagine what its doing inside my motor...Has anyone else noticed this and know the reason/cause for it?

I want to do this flush myself, where is the easiest and lowest place to drain the coolant? While flushing it several times, can i just fill it with water and drain it to remove all the Dexcool?

Thanks again guys,
Eric

The sludge comes from two different ways. First, if someone topped the coolant off with non DEX, it will sludge bad. Second is air getting in to the system, this can happen if the tank gets low.

When I flushed mine I removed the lower radiator hose and let it run out. Put the hose back on and filled with water. Ran engine until I saw it moving in the radiator and then shut engine off, removed lower hose again to drain it. I did this 7 times. Make sure you have clear water coming out. I would suggest putting a bottle of flush in there on the first fill to help clear out any sludge.

The overflow tank is not sealed and therefore air is present. Dex is oatmeal based, air allows it to become oatmeal again. Inside the cooling system should be mostly sealed and stay relatively sludge free.

What is the total capacity of the cooling system on these cars?

Billboost:
You mentioned some routine maintenance being my car is 5 yeras old and having 78000 miles on it...Heres what im considering, and a few questions. And also, would any of these have been done already since my car was recently purchased and a GM certified used car?

1. Radiator Flush
2. Trasmission Flush
3. Greasing complete front end...however most of the joints are completely sealed with no grease fittings, any suggestions to maintaining these?
4. Of course routine oil changes...i change mine ever 3000 miles with filter

Any other suggestions to making my car last to 200,000+ miles?

Thanks!
Eric

I've been out of the buying from a dealership for quite some time and am unsure of what GM does to certify the car. Take a look at the paperwork etc to ascertain if any have. If not.....well then.

Fuel filter
Some Techron fuel cleaner in the fuel tank
Trans service (no need for a flush, a service will do well)
Check grease fittings/boots
Coolant flush

Would i be able to do a Trans Service myself, almost sounds like taking it somewhere and having someone look at it.

Arent most of the grease fittings sealed on these cars? If some are able to be greased, they will be listed in the owners manual..correct?