Don’t Mix Your Coolants. Don’t. Just Don’t.

Taking care of a 1991 Pontiac 6000 with (as of today) 149,000 miles on it can be a daunting task.  There are issues that can be minor annoyances – I have to replace the weatherstripping on the front passenger door – and issues that can be major concerns, and that’s what brings me to today’s post.

Coolant.

In a nutshell, if you don’t have enough coolant in your car, your radiator will fail.  If your radiator fails, your car turns into a four-wheeled paperweight.  That, and you’re paying up to $175 for a new radiator, plus $$$$$$$ in labor.

So when my Valvoline Service Center, the one on the corner of Central and Colvin Avenues, told me that it was time for my 6 (the colloquial nickname for my Pontiac 6000) to get a coolant flush, I made sure to take care of it.  But here’s the issue.  There are several different coolant fluids available, and putting the wrong coolant in your car is like giving a blood transfusion to someone without knowing the blood types.

And thus brings me to something called DEX-COOL.

Apparently General Motors cars are supposed to use DEX-COOL coolant fluid, mixed 50-50 with water (you can purchase it pre-mixed).  So I was just about ready to go to Pep Boys and get a bottle of DEX-COOL and take care of the situation.

But since I had to go get a coolant flush anyways, and since my Valvoline fluid guys are capable of checking my car’s oil and other fluids, I had them take care of checking my coolant levels.

The Valvoline guy hauled over a fluid transfer device that sucks up all the old coolant, flushes the system, and puts new coolant in.  I noticed that the new coolant going into the 6 was green.

Waitaminnit – wasn’t I supposed to have orange DEX-COOL fluid put in the car?  I know that when my car passed 100,000 miles, I switched my oil from straight oil to a full synthetic, and once you start using full synthetic, you can’t change back.  “Shouldn’t DEX-COOL be put in there?”

The tech pointed at the vat where my previous coolant was stored.  It was dark green.  Universal coolant.  Not DEX-COOL.  “You’re fine,” he told me.  “You can put green in here, or you can put in Prestone’s yellow coolant.”

“But what about DEX-COOL?  Aren’t I supposed to use that for GM cars?”

Well, apparently two years ago there was a class action lawsuit about the use of DEX-COOL in GM cars, to the point where DEX-COOL actually eats away at the interior parts and can cause serious damage.  Apparently my car ran well on the green universal coolant, and now that there’s been a coolant flush, I can continue to use green coolant without fear of my radiator turning into a sieve.

See… this is why if I don’t know what I’m doing with auto repair, I can go to either Valvoline or DePaula or Monro or Midas.  Or maybe find myself a shadetree mechanic.

And if I need to get an air freshener for the 6, there’s always Pep Boys.