Swaggs1305

I have an 03 350z Touring with about 133,000 miles on it.


Recently the temp gauge has risen slowly to about 60% after 45 min of driving or whenever I have to go on the highway. Was concerned so changed the oil and seemed to fix it for a bit.


My dad also likes to drive the car from time to time. He noticed it started to get a little hot as well and filled the coolant. He knows a lot more about cars than I do so I let him do what he feels best. I just try to learn slowly helping him fix issues.


Most recently the temp gauge climbed dramatically when I drove it. I drove it a few miles to a car dealership (passed my real estate exam and needed a 4 door). It was about 75% to H, I had to get to the dealership so I put on the heat trying to draw it away in which it lowered it just a tad where I was able to make it. I left it at the dealership to cool off and get it the next day.


The next day I make it about 2 miles until the temp gauge is as high as it can be so I pulled it into a gas station and left it there. Tried turning on the heat to see if that would make a difference but instead of blowing hot air it is extremely cold now. Turn off the car for a few minutes, turned it back and the temp gauge is back to normal. But when I try to drive it after, the gauge skyrockets again within 15 seconds.


As hinted above I am not the best with diagnosing problems or fixing cars as I try to watch and help my dad and brother-in-law as much as I can.


Reading other posts could this issue be caused by my dad adding coolant and air may have been trapped? Or also a t-stat is my other thought before thinking the worse on a head gasket.


Can anyone give their thoughts and things to try to find/fix the issue? I would greatly appreciate it and will try to get back as soon as possible with updates. With my brother-in-law being busy with work and likewise for myself, it could take a while to test solutions but will certainly try to get to it as soon as possible since I miss driving it......


THANK YOU!

dkmura

iTrader: (64)

Welcome- your post could also have been labeled "Overheating- need help", which is a common topic here as we hit summer. Do a bit of searching and you'll find plenty of posts on the topic with some being blown head gaskets and some with other causes. In general, a blown head gasket usually results in coolant mixing with engine oil. Extreme or repeated overheating may cause a blown head gasket. But overheating is a serious problem and you're right to stop driving your Z until you solve the problem.

There are tests that can help determine if the head gasket is blown. Ask your dad or bro-in-law if they can help you do a compression test. You could also have a used oil analysis (UOA) done by a lab to see if there is any coolant mixed in with the oil. Either of these tests are useful in confirming the health of your VQ engine.

As you say, it could also be trapped air in the cooling system or it could be a defective radiator cap or crack in the coolant tank or upper or lower radiator hoses. When was the coolant in your Z last changed?

bealljk

iTrader: (13)

DK has some good insight. I would look at your oil cap, is there anything creamy on the bottom side of the cap? Does your car spew out white smoke when you accelerate hard?

I would trouble-shoot your coolant system first. If your thermostat is the original one it may be worth the trouble to replace it regardless if it's the culprit, you'll then go and refill your coolant system and bleed (and bleed again, and again).

FOOKhonda

iTrader: (1)

It's the thermostat.

It's a real PITA to bleed the system, youll think its done, try to drive it, and it will still overheat, there's also a bleed valve on the coolant pipe towards the back, it may help a bit, but there's tons of methods to bleed it, it works differently for everyone so give some a shot.

dkmura

iTrader: (64)

To properly bleed the cooling system, it helps to use to right product and take your time. Here's what I use:

terrasmak

iTrader: (8)

Yup, get one of these. Then replace the thermostat and cap and make sure it's bleed well.


You can also jack the front of your car, get the tires 6 inches off the ground. Pull the cap and coolant bleed port cap, add fluid. You should be able to tell if there was air in the bleed line. This way is not perfect, but will get you going. It will take a few times to get all the air out