Hey guys. Ill keep it short and simple. My temperature in my '86 Silverado had been fine for a month (about 160 degrees) but the coolant was just a tad low so I bought some pre-dilluted antifreeze and topped it off.

That just caused a ton of problems. The next day she started leaking antifreeze. I fill the coolant back up every afternoon but she still warms up to about 210 degrees at red lights, 160 on highway. I popped my hood and saw it was steaming a bit from the ends of my hoses. I tightened up the clamps so it seems to leak slightly less now. Still a little bit though.

I checked my fan and its fine. That refill tank that you put coolant into seems to be sucking antifreeze down, is it dripping that fast even though I tightened my hoses or is it just filling up the radiator from when it was low?

So my main question is why did adding coolant seem to cause this problem?

Also, my Firebird runs great at about 210-220 degrees. Is my 350 gonna get damaged at 210 degrees?

And lastly, any help would be greatly appreciated

 

You need to fix all the leaks! Your cooling system needs to be sealed. The cooling system needs pressure in it to raise the boiling point of the coolant. The cooling system will draw coolant from the coolant tank when the engine cools down if it needs to. It is possible your cooling system was down a lot of coolant and was giving you some weird readings. It is a must that your cooling system has no leaks and a good rad cap. Get your rad cap tested or replace it with the right one.

 

It did not start leaking when you added coolant, it was already leaking. That is why you had to add. The cooling system is sealed, it will never go low unless it is leaking.

 

And i dont know about the 86's but one time i put regular anti freeze in my truck and it would heat up higher and put a pin point sized hole in my main hose. i replaced the hose had to drain the radiator and flush it then put dex-cool antifreeze it fixed it all... then the next week i hit a flock of quail and did it all over again. but make sure its the right anti freeze. i dunno if yours requires Dex-cool or not