My car began overheating a few days ago. And it happens all the time, probably after 5 minutes of use.

I took my car to a local (and reputable) mechanic shop (Infiniti Master Techs) for an oil change and inquired about the overheating issue.

As soon as the car was on the lift, the mechanic said something along the lines of "the car is cold at the bottom. Some of the hoses are not warm." Not really sure what that means, but he then proceeded to tell me it could be the thermostat. Note that this wasn't a thorough check, I simply just asked him to do a visual check.

As I drive back home, the car once again starts to overheat a few minutes into my drive. Fast forward back home, I can here some weird noises going on under the hood as soon as I turn the car off.

I pop the hood, and can here a purging sound (the sound you'd here when you're getting water from your water dispenser with the 5 gallon jug on top). I can also see bubbles rising to the top on the coolant reservoir tank. And I can here a 'dripping' sound coming from the engine bay as well, but no coolant is spilling or dripping down to the floor (no visible signs of a leak).

Based on the symptoms described, what can the source of the problem be?

The fan seems to be running, although I wouldn't know if its running properly or not. I have already read a few threads and sticky's pertaining to overheating in the early year sedans. This is my only vehicle so I need a fix asap.

 

Once the engine is warm, is the upper radiator hose solid? Full of pressure and tough to squeeze. It's right in front of the windshield fluid/coolant tanks. The fish tank sounds you hear seem to be air in the coolant lines. Just wondering if you need to bleed the coolant system, but yes it could also be a thermostat.

 

I'm def sure it's your thermostat. It's supposed to open to allow coolant to flow once the engine is at operating temp. Mine went up a couple months ago- I noticed my fan would kick on and stay on until I turned the car off. Shortly after, I noticed the needle on the temp gauge rising (never fun to see). Didn't have time to change it myself so the stealership got me for $490 on a < $90 part. If you're gonna do it yourself be sure to purge the system of air completely or your overheating issues will continue.