ok, i was driving last night and all of a sudden the temp gauge went from normal which is a 3 bar to like 5 bar near the H. Im not a car expert but,

im guessing its the coolant is low ,which causes the temperature to rise up to 5-6 bar? is that right ?

 

Did you recently do something with the coolant? If you didn't bleed the coolant right after a flush, it can cause that as well. If not, check for leaks. Check all your hoses for tears.

 

unless you are using the modifry temperature converter that is realy bad

I've seen a 4 briefly on trackdays, I would not run the car till you find out whats wrong

 

If it jumped really quickly then something electrical is probably wrong. If it took maybe 20 or 30 seconds to do it then it could have over heated. Did you continue to drive, or did you pull over after this happened?

 

i pull over and check itwas night time at the moment, i check under the car and the hood, there wasn't any leak. I pull over at a QT and bought some coolant, i check the coolant fluid and it was low. i fill it up and while driving home for like 15min the car was fine. But then i got home it went up to 4 bar.

 

i just ask one of my friend and he said it was the themo stat that needs to be replace.