2002 Chevy Malibu- Overheating

I’ve replaced the heater hose after it “popped”, water pump and the radiator cap twice now
Check engine light was on before it’s last trip to the shop, and off when I picked it up so he said it must’ve been fixed
I assume it’s normal to always run at the middle on the temperature gauge but after maybe 10 minutes it’s at the middle of not a notch above
It fluctuates very quickly between below middle, middle, and a little above
I’ve been to two shops on my time about 6 times, I’m just fed up with no results
It’s my first car, I work at McDonald’s, and am a full time college student
I need to know what’s wrong so I’m not just wasting money on wrong things
Please help, thank you!

As long as the temperature gauge doesn’t go into the red zone (overheating), the engine coolant is operating at the proper temperature.

But what can happen is, if an overheating event does occur it can damage sensors and sending units for the coolant.

So if a heater hose popped and coolant was lost causing overheating, it may have damaged the coolant temperature sending unit for the gauge.


Here is a pic showing the sensor.

After the popped hose and its repair… The cooling system needs to be burped of air pockets after a hose is replaced and also after you notice rapid fluctuations of the temp needle.

These rapid fluctuations are or can be caused by an air pocket in the cooling system. The air pocket will usually exist up high in the system…right where the coolant temp sensor will reside. The engine will warm up…and the temp needle will try to give you a reading…then for whatev reason the air pocket finds it was up to the temp sensor…and the tip of said sensor will find itself in an air pocket…and Not with its nose in solid liquid coolant with no bubbles in it… This is when you see the needle drop…and then rise… when it goes from air pocket to solid coolant.

The air pocket will work itself out in time…but its best to sort that out quickly and intentionally before driving the vehicle and possibly damaging the engine.

We talk about this air pocket on this site Ad Nauseum. When the engine is cold…make sure you fill up the radiator and top off the coolant overflow container. When you go thru several Hot and Cold cycles this air pocket can and will work itself out in time…but it takes several hot and cold cycles and a topped off and functioning overflow container. It also takes a properly sealing radiator cap and a properly working overflow.

Many cars have a bleed screw on the cooling system somewhere in order to burp this air pocket out of the system…the ones that don’t have this…need to be burped using the method I described above.

I wish we could make a page with this info in it…because I cant count how many times I’ve described this scenario to people…its super common. At least this burping is something you can do on your own with no tools at all… Just a gallon of coolant.