Radiator reservoir boils

i just bought a 98 dodge stratus yesterday. i drove out to my inlaws place (15 miles or so) and when i shut the car off, after a second or two, i hear a boiling sound. the same thing happened when i drove 10 miles to my parents house, but when i drove back HOME from my parents house, there was no boiling sound, so its not happening consistantly.

i'm sure its the readiator reservoir boiling. what could be causing this, and what needs to be done to fix it?

I had the same problem. Your loosing water somewhere and air is getting in to replace that volume. Turns out I had a radiator leak. I put in some stop-leak as a temporary measure till I can save the money to have it done. That worked for a couple months now.

Radiator cap is wearing out. I had this problem in my '97 and my '00.

And a side note for you lucky, that stop leak stuff (usually aluminum or copper filings) is pretty hard on the system. It's definatly temporary. Also if you have to have the radiator replaced, have the thermostat replaced too. it's right on top of the engine and not hard to get to.

But definatly try the cap first. That's such an easy thing to replace. It's less then $20 and takes 5 min once the car cools. And that includes time to wash your hands. :)