OK. So I just took my truck to the local radiator shop for a complete flush and fill and a new thermostat as I'm knocking on the door of the 100,000 mile club. When they were done, the guy at the shop told me to check the coolant level in the over-flow tank when I got home and if it was low at all to bring it back and they'd top it off.
So I did as I was told and popped the hood when I got it home. I notice two things right off. #1. The coolant level is fine. #2. The coolant is more of a yellow than the reddish color of the factory fill. So I break out the owners manual and it says only Ethylene Glycol based coolants with HOAT
(hybrid organic additive technology) are to be used.
I call the shop with my inquiry and they inform me that they indeed use an Ethylene Glycol-based antifreeze. It's an extended service life blend rated for 5 years-150,000 miles and "compatible with any color anti-freeze and any cooling system... foreign and domestic". But when I asked them if it was HOAT
, the response was, "what's that?"
So.... did I just poison my cooling system and the engine, radiator and heater core is gonna melt down into a smoldering lump of goo or is it OK to go HOATless when a full flush and fill is done???