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Coolant -- is my mechanic telling me lies?

I?ve got a 1993 Toyota Corolla with 140k miles on it. 5k miles ago I drained and replaced the coolant myself. The stuff I drained was red (I think this is Toyota?s proprietary coolant) and I replaced it with green Prestone ? and it specifically said on the jug that this stuff could be mixed ?with any color coolant.?

Well, 5k miles later my radiator cracks and has to be replaced. My mechanic (a local guy, not the dealer) told me:

a) I had been using ?cheap coolant? and this may have contributed to my radiator cracking

b) I should only put ?genuine Toyota coolant? in the car and never use anything else

c) In fact, my use of the green coolant was such a bad mistake that he had to charge me an extra $50 to ?flush? my coolant system to make sure all that ?cheap coolant? was really gone before he could put in the genuine Toyota coolant.

I?m looking for some opinions on all three counts. Could using that Prestone coolant really have contributed to cracking my radiator? Should I really only use genuine Toyota coolant? And was that $50 flush really necessary?

All opinions are welcome! Thanks!

Here are my observations, based on 250K miles ownership of a 94 Corolla:

  1. Not sure Toyota Red was factory spec at the time.
  2. Still used Prestone green from the first change at 30K to now. Radiator is doing fine.
  3. Some level of extra flushing might have been required, but $50 worth of effort/chemicals??

If you otherwise trust your mechanic, then use him and Toyota Red Coolant. Note that I have done the exact opposite, and have achieved perfectly good results. I tend to believe that your radiator ran out of time in 2010 and needed replacing, regardless of what you did 5K miles ago. Most radiators don’t last forever. I would not blame the leaks on the coolant.

Frankly, a car that old was due for a cracked radiator. It may have had nothing to do with the coolant. In fact, I am willing to bet the coolant had nothing to do with it. I think it was just age.

Using the coolant Toyota specified for your vehicle isn’t a bad idea. It’s what I would have done in the first place. However, had you used the proper coolant, I believe you would now still be dealing with a cracked radiator.

Your mechanic probably isn’t lying to you. He might believe everything he said, although truthfully he can’t know for sure. In all honesty, both he and I are speculating on the cause at this point. Neither of us can know for sure.

Plastic radiator tank failure has NOTHING to do with the coolant. Your car is 17 years old…other things are going to fail too…

In my opinion…yes. The best coolant that has ever been marketed (in my humble opinion) is the green stuff. Coolant had nothing to do with the failure of your radiator at all. The Toyota red coolant has nothing extra in it to make it any better than good old ethyl glycol. I think your mechanic is too “brand” specific when it comes to making choices for you. Make your own choices. He just flushed your wallet of an extra $50 because he could. His excuse is very flimsy at best.

Is he telling you lies? Probably not in his own mind. He is simply misguided. (of course that is just my humble opinion). Was your flush necessary. No. Most shops have policies and beliefs. Many of these came about prior to the term “urban legend.” Many also came about as “revenue generators.” If the jug you used said it can be mixed with any color coolant, I’d tend to believe that. I don’t think the manufacturer would want the liability if it were not true. I’ve used the same stuff, without any negative results. I think your radiator cracking shortly after changing antifreeze was purely coincidental. I have some pretty strong feelings about other “revenue generators”: You don’t have to flush your brake fluid under 100K miles, automatic trans fluid will do no harm if it stays in place for 100K miles (if that’s what’s recommended by the manufacturer), power steering fluid doesn’t need flushing under 100K miles, topping off your fuel at the filling station will not usually ruin (or saturate)a charcoal canister. (only happens on certain dual tank vehicles), pure nitrogen in your tires, if free, is a good deal, as it will not allow pressure changes with temp. changes. (that’s why they use it in aircraft tires and other aircraft presurized systems). Now some of my above beliefs might hit a nerve with some of the long time posters, but hey, that’s one of the nice things about living in this country, right?

Mechanics can become loyal to a fault with products and brands and even methods. Even to the point of appearing obsessive-compulsive. But not me, of course.

Although I’m not aware of this problem with Toyota’s red coolant, some coolants do not mix well. It’s always a good idea to use the coolant recommended by the manufacturer. The corrosion inhibitors work differently in different types of coolants, and using other than that recommended could compromises your corrosion protection.

Having said that, the green coolant may not have had anything to do with the radiator cracking. But, as the article I linked you to pointed out, it might have depending on its specific formulation. It was more likely just age and wear.

Personally, I think your mechanic did the right thing. And I think the $50 was a reasonable price.