Here's the full range of possibilities and how to diagnose each one.
http://ricksfreeautorepairadvice.com/my-...
It has a blown headgasket, a very very common problem in these cars.
maybe you should of paid more close attention to ur dads mechanic cause all these other answers sound way off. just like how u didnt listen to someone that was looking at ur car giving u advice, they're not really listening to ur details.
But ill be nice and give u my take on it. Did u guys or whatever shop fix ur car bleed out the coolant correctly? The cap was missing. All the coolant came out and air replaced it in ur coolant system. You introduced air pockets into the system and lower its efficiency. It gets really hot in the coolant system of an engine. air bubbles and air pockets can cause ur system to over heat. you CANNOT just put a new cap on, pour in some coolant and say "there DONE."
So no radiator cap and switching out the thermostat multiple times without bleeding the system correctly will cause that type of over heating ur talking about. It causes air pockets in ur system. It hurts ur water pump when there is air in there. its meant for coolant/water. As ur driving, ur water pump is pumping faster due to the higher rpm. once u idle ur pump is working slower, the air pockets stop moving around much and find a spot in ur cooling system. That spot is no longer being cooled and the heat add up fast. and it causes ur engine is over heat.
That would be the cheapest thing to check first. Just go out and buy 20 bucks worth of coolant. (make sure its the same color of the current coolant) make a 50% coolant 50% water mix. Watch a video on how to bleed out air from ur coolant system. it takes like 30 minutes. Add on another 30 mins to find and watch a video. ur done in 1 hour for the cost of 20 bucks plus some gas money.
if someone did correctly bleed out ur system the last time the coolant system was touched,
(i say the last time because if u changed ur thermostat and bled the system then change ur thermostat again without bleeding the system, u still have the same problem)
then i would have ur dads mechanic take a look at the water pump. (assuming the fans are working)
that may also be the problem.
When you mentioned the overflow tank it reminded me of my kids Ranger.If you service the radiator properly and then you let the car warm up to operating temperature and you see water pouring into your overflow tank you do have a blown head gasket for sure.If this isn't the problem and you have electric cooling fans make sure they are both working when you get the engine hot and have the A/C on.
I have a 2005 Nissan Sentra that has been over-heating like crazy. It started yesterday when I noticed that the cap on the overflow tank was missing and the water was boiling really bad, the cap for the overflow tank was loose to begin with and was missing when we opened the hood. My dad had the car inspected and replaced the thermostat the day before. We thought that might be the problem, so we purchased another thermostat but this time from the Nissan dealership. My dad also purchased a new lid for the radiator.
Today, I was driving on the highway when the car was over-heated and the needle was all the way up to the "H". I stopped and waited for a couple of minutes for the car to cool down, then I proceeded again. After four hours, I was going home and began to notice that the car only started to heat up whenever I stopped for traffic or a red light. The needle went all the way up to the "H" but as soon as I started driving again, the car would cool down about halfway. It continued anytime I stopped or drove.
One of my dad's friends/mechanic said it might be the water pump in the motor/engine (or something like that, I wasn't paying close attention). I really don't know what it could be but I would appreciate any insight as to what is wrong. Thank you!
