I have an 03 350z with 99k miles and heres my issue
(please lmk if you need more info to help you help me come to a conclusion)

Over the last 1000+ miles or so my car has overheated diff times

the first time it happened i took it and had the thermostat replaced thinking it might not have been letting coolant in...when i noticed the gauge was still reading hot i took it to have it flushed/burped and there was an airpocket. Car ran normal temp for about 400 miles

2nd time this happened i took it up to the shop again and had them do another flush, check the WP and pressure test the system for leaks..they said everything was working fine but there was some air in there again but it was running normal temp again...10miles later the gauge went up again but shortly after returned to normal, i was a little concerned at this point and puzzled

Finally as of recently (another 450 miles or so later) the temp went up again (wtf?) and at this point im thinkin something is seriously wrong here...so i go up to the shop and ask them to check it again (at this point there doin this for free since im a frequent customer) and they check for air again, which there was and the rest of the system..still nothing they can find so they refered* me to the dealership

Basically they are saying i could be burning coolant internally/ leaking somewhere they can see externally.....Also had heard my head gasket could be going, I know this is long but i wanted to try and give the details ahead of time

Please lmk what you think, and like i said if you need any more info to better help your answer just ask and ill answer to the best of my ability

THANK YOU

ALEX

 

im not an expert, but i noticed your about to hit your 100k. isn't there a service for once your on 100k or was it 120k to get your water pump changed? I can be totally wrong on this.

 

You could have a bad thermostat. I bought two of them and they both were getting stuck, then on the third time I bought an oem thermostat from the stealership, problem solved.

If you suspect a coolant leak, I recommend you top off the expansion tank to recommended level along with the radiator. Then pump recommended pressure into the system using a special radiator cap/pump.

Put that bish on jack stands and remove the engine under shroud. Leave it over night and you should be able to find your leak.

It could be your water pump or head gasket, but let's not jump to conclusions so fast, try the small stuff first. Good luck bruh

 

Couple suggestions. Check ur oil 4 water. U don't say where ur from. Is the air conditioning running? If so, r both fans running? There's been a recall, but ur out of the window.

 

I will be contacting nissan on monday, b/c its easter weekend they are down for the weekend service side but i will check on that concerning the water pump


Ok i will look into that for the OEM thermostat when i contact the dealer..i might just do that to be on the safe side considering when i replaced my thermostat i got it duramax frm autozone (maybe a bad move)

im in florida btw and yea when its running hot i put hot 90 degrees on and the air comes out cold for a bit then finally gets hot after awhile and yes both fans are running

 

If this happened right after "breaking the seal" I wouldn't worry too much, as this car is tough to bleed properly and will heat up until it bleeds itself. But if this happened weeks after opening up the cooling system that means there is a genuine problem. Dont over-look the rad cap if your car has a new t-stat, been pressure tested, and is not burning/leaking coolant. Radiator caps sometimes lose thier ability to pressurize correctly and that will cause over-heating.

Also does the heater work well when it is overheating?

 

I have a 03 350z too and mine is currently doing the exact same thing. I replaced the thermostat and water pump. We also flushed it and it was okay for about a week and now it's running hot again. What did you finally do to get it running normal again?

 

I have the same problem in my 06 350z, i just bought a new water pump and an new thermostat, i also both the bleeding funnel for the radiator. i will over hall everything this weekend when it stops raining.

This will be my 3rd thermostat this month, i also got a radiator and new fans, and it still over heats.

my 350z over heats about a min after the fans kick on, and a squeaking noise comes on, it sounds like the belts but i am not sure?

did anybody solve their overheating issues? what was the solution?
please help my 350z is been sitting for almost 2 months now

 

I'd go with a bottle of Prestone Super Flush, follow the directions on the bottle and flush the whole system. Look for rust when you collect the flushed coolant. Any parts that get replaced after that (i.e., thermostat, radiator cap, etc.) should be OEM. Check the fan relays and make sure that the fans engage (either use a bi-directional scan tool to engage the fan or a Power Probe to apply voltage - ONLY IF YOU KNOW WHAT YOU ARE DOING). Fill the cooling system using suction to avoid air pockets. Use Nissan coolant; they're sort of notorious for using proprietary chemistry on all their fluids. At $25 a gallon, you're gonna hate me for saying it, but I wouldn't use anything else (with the exception of the engine and differential oil). How did the shop check the pressure coming out of your water pump? If you can get to the pump, sometimes you can put an engine stethoscope up to it to listen for a bad bearing or impeller. Not sure how you'd check the pressure coming out of it though (unless our car comes with a coolant pressure sensor that I'm not aware of.)