Engine Block and Belt Tensioner Pulley Corrosion

[XEusioN]

I have a problem.

Apparently the coolant from my radiator overflow tank had boiled up and over the top and into my engine bay. Combine that with the radiator fans running at full blast, I had a coolant spill on my engine block and belt tensioner pulley. The odd part is, the fluid is corroding! WTF? Antifreeze isn't suppose to corrode!

Well Toyota uses some weird pink/red/purple antifreeze and it's destroying my belt tensioner pulley bearing and causing a squeeling sound alongside a weird noise when revving the engine.

I know there's a TSB out on the pulley making squeeling sounds, but I'm out of warranty (just hit 62,000 today) and doubt that's the sole problem. I'll have to check my VIN # tomorrow to see if I have the "fixed" tensioner pulley or not.

Now I'll have to go to the dealer and ask WHY didn't anybody notice the corrosion all over my engine block during my 60k mile service, or any of my other oil changes every few months. I'm going to have to steam clean my engine bay, replace my tensioner pulley and bearing, and figure out WHY my coolant boiled over.

Was it overfilled? (Doubt it) Or is my thermostat sticking?

Has anybody else had any issues like this? I'll get some pictures tomorrow

Thanks,

-James