93Mustang5.0

My car gets hotter that it usually should, especially during traffic or stop lights. I have a brand new stock radiator in it and underdrive pulleys. I dont think that those pulleys should make the car get that hot, that quick. I noticed that I dont have an overflow tank. Instead the previous owner but a windsheild wiper fluid bottle in my fender with a tube going into it......

I definately think that if i bought an overflow tank that was made for the car it would solve the problem, but i'm not sure. Basically this bottle is a open bottle with a 5/8 tube going into it and coming out attaching to the nipple on the radiator. My radiator was full after I topped it off and burped the system, but now I can open the cap up and see that its not completely full when the car is turned off...

94Blk5.0

Getting an overflow tank should help. And is the t-stat good? Afresh 195* might help or a 180* if you still have cooling problems after the addition of the over flow tank.

93Mustang5.0

Yeah it was brand new when I installed my intake and throttle body last summer.

93must

I dont think a new bottle will do you any good! All it is there for is when the fluid gets hot and expands it has a place to go, then when the car cools off it sucks the fluid back into the radiator! As long as the tube going into it goes all the way to the bottom it should be fine! Check the fluid in the radiaor when the car is cold! If it is down some then add some till its full, then depending on how big your overflow is you need to put som in it also! I think the stock one is about 1/4 full when it is cold! Then when the car is hot check it and make sure it is not overflowing out of the bottle. If it is then you filled it to much when it is cold or the bottle is not big inough! If thats not it then it could be the t-stat or air in the system. Underdrive pullies can effect the temp because it slows the waterpump down. If you live somewhere that is very hot most of the time then that could be it also! very hot being 90 or above all the time!