Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hey there, thanks for your question.
So your temperature gauge is fluctuating while driving? from hot/cold?
WHen it fluctuates, does it move slowly or is it erratic and goes from hot/cold rather quickly?
hey, can you chat a minute?
does the heater work normally?
Ok, since we can't seem to catch each other the chat here, I will explain some things.
If the gauge is fluctuating there are a few possibilities. There could be air in the system, the temp sender could be bad, or it could be more serious like a headgasket issue.
Ideally you want to start simple here by burping the system to make sure there aren't any large air pockets causes issues with the temp readings. You need to install a coolant bucket 1/4th full and warm the engine up, once warm you rev and hold at 2500RPM's in 1 minute intervals to clear any air pockets. Once it stops bubbling and heat remains nice and hot at idle then the air should all be out.
If you burp the system and the symptoms remain you want to test the temperature sensor sender with a meter to see if resistance specs match coolant temperatures.
IF all that checks out and the temps are still sporadic while driving then you need to test compression and/or pressurize the cooling system and check for cylinder leaks to see if the headgasket is bad.