Boiling Antifreeze

Hey all;
So I was racing last night, and my boy pulled up next to me and was like "Your engine is smoking." I popped the hood, and sure enough, it was. But not the engine. The coollent tank was bubbling (like boiling water) and I guess steam was coming out from the breather coming off the tank. The engine was then running EXTREMELY hot! My tank has been cracked, and Ive repaired with a clay-type fixing compound. Im going to buy a new tank from the dealer today. Anyway, what would cause it boil? and steam out? Ive never had that before. The car has never ran that hot either. I want even pushing itt htat hard.

mine did that too a few weeks ago, I just flushed out the system and threw in some new coolant with a small bit of water and it seems to be workin just fine now, just try swappin in out with some newer stuff and see if that works, It might be one of your coolant sensors or somthn is out,

It is pretty new. Did that about August last year. Should still be good. Its still bright green. Also when it leaked a couple weeks back I refilled.

Assuming you have never replaced your radiator, it's now 10 years old and has accumulated a significant ammount of limestone inside it or your core has begun to rot away (take one of your fans out and run your finger on the core from the bottom, if pieces fall of thats your problem). Therefore you radiator does not have the capacity it is supposed to have causing the coolant to boil faster since there is now much less of it. I had the same problem even though there was no leaks on the rad, but sure enought, not to long after with the added pressure, the rad started leaking from the core. A replacement rad should be no more than $250 (don't buy a re-built one, they are not much cheaper) and is a very easy replacement that you could probably do yourself. Roughly a 45min job.

Make sure that you don't put in straight coolant, unless it is pre-mixed. You need about a 50/50 mix of coolant and water. This raises the boiling temp. so the coolant dosn't boil at it's normal point. More coolant than water, and it's just not as efficient. More water than coolant, yeah you can guess the problem there. Check the radiator for leakage and build-up like the last guy said, and then flush it and put in new coolant with a 50/50 mix.

also in case none of these is your problem,if you have a blown headgasket, you could be pumping exhaust into your cooling system, this would cause it to bubble,like it was boiling, i know because this was one of my problems too.

I did a 50/50 mix when adding. I havent had the problem again. I ordered a new coolent tank from the dealer. Im thinking that the clay stuff that I used may have went inside and blocked something. When I get the tank, Im going to flush the whole system. I dont think I have a blown head gasket... I would have noticed the symptoms... I hope. lol. It's been fine the last couple days, but I havent driven it as hard as I did that night.