Hi all,
Winston (01 D2) was purchased a year ago and has the orange coolant. I had to open the coolant system, and was wondering if I should flush it out and replace it with something else. I researched coolant on an auto parts website, and found:
Yellow OAT
Green Conventional
Blue HOAT
Orange OAT
Purple HOAT
Pink OAT
Red NOAT
Violet Hybrid OAT

Some of these are recommended for diesels. I am debating where to spend my money. Any tidbits of advice/knowledge appreciated.
Lisa

 

Hey @Lisa Bunch ... I would highly suggest that you flush “all” the Dex-Cool orange coolant in your cooling system and replace it with anything else other than Dex-Cool. You definitely can’t go wrong using conventional green coolant for cheap and it’s great for our V8 engines.
I personally use Valvoline’s Zerex G-05 HOAT coolant in Myrtle.

 

OK, so it's the orange OAT (dexcool) that is the problem, not just OAT. We all have such problems with the cooling system..

 

So this is what happened:

What exactly is Dexcool?

In the 1990s GM introduced an engine coolant called Dexcool. It's supposed to last 5 years or 150,000 miles but there have been problems with this coolant. Cooling systems that use Dexcool exhibit more acid buildup and rust in the system when the coolant level gets low and oxygen is allowed to enter the system. The acid eats away at head gaskets and intake gaskets. Rust builds up in the system, inhibiting coolant flow, which causes overheating.

Overall, numerous cooling system problems have been attributed to the use of this controversial product, although GM firmly stands behind it. There were class action suits against GM on this issue, and GM reached settlement agreements with some owners beginning in 2008.

 

I've constantly read that Dex-Cool is bad for engines especially when mixed with conventional green coolant gels up the coolant.
The Brits over here still love using Dex-Cool and swear by it especially for their Diesel engines.