AREIFEL

Ok i have a 2005 v6 mustang with about 50,000 miles. It has been running perfectly as long as i have owned it. I usually drive back and forth about 80 miles on weekends from school to home. Now the problem i am having is i will make sure the coolant is in the cold fill range and then drive the car all the way to my destination. the temp is in the middle and everything sounds good.

Now as soon as i arrive at school and pull in to the parking lot i still have the same temperature but when i get out i hear splashing noise under the hood. when i take a look at it the fluid seems to be bubbling out of the resivior cap pretty harshly. this happens everytime i drive the car and stop it. but while the car is runningi noticed nothing is wrong with the car. i can not see any leaks and there isnt any white smoke coming out of exhaust so i dont think it is the head gasket.

What could cause this? and how can i fix it?

if you need any more info about the car ask.

Nuke

If you're not seeing any temperature fluctuations, white smoke out the tailpipe, oil in your coolant or a milky color (or any other strange color) to the oil on your dipstick, then rule out a bad head gasket. From your description it sounds like your cap is not sealing properly. Check that there's no crud underneath where it seals to the reservoir and be sure to tighten it properly. If it still leaks out, replace the cap. The cooling system requires a good seal.

And if it was your t-stat, you'd be overheating and you'd see that on your temp gauge.

AREIFEL

Would a faulty thermostat be to blame. i just changed out the cap twice and same problem.

Nuke

It's possible but I'd think you'd see some overheating, at least by the temp gauge (unless our temp gauges are a go-no-go type of indicator) if it was the t-stat. Do the threads on the reservoir look ok? Maybe the caps are good but somebody cross-threaded the cap and it damaged the reservoir neck.

AREIFEL

Ill check and let you know. if that is the case i should replace the whole resivior ?