Can we talk about the coolant I pulled from a 2018 Silverado that looked like chocolate milk after just 18 months?

The owner used a 'universal' green coolant instead of the Dex-Cool it called for, and the mixing caused a sludge that clogged the heater core and cost him over $800 to fix, so has anyone else seen this happen faster than expected with the wrong mix?

4 comments

4 Comments

patriciagarcia8d agoMost Upvoted

Forget the sludge for a second and look at the bottle. That "universal" label is the real problem because it makes people feel safe mixing it with anything. The chemistry is never truly universal, it's just a compromise that works okay until it doesn't. So the angle is that the marketing on the shelf is setting up this exact failure by making the choice seem simple when it's actually really specific.

brooke_taylor1mo ago

Eighteen months to make chocolate milk in the cooling system is a new record. That universal coolant must have been in a real hurry to turn into a science project. I guess the upside is you don't need a snack while you work on it. Saves a trip to the store, just open the radiator.

felixlane29d ago

That sludge probably started forming the second he poured that "universal" stuff in.

kelly.patricia1mo ago

I mean, that's rough but honestly not the worst I've seen. My buddy's old truck had something similar happen, but it was from just topping off with water over and over instead of any actual coolant. Ended up with this nasty brown jelly all through the block. Maybe it's just me but people really don't take the fluid stuff seriously until it's too late.