I tried looking through the forums to find my answer before posting but couldn't find what I was looking for. So here is my problem, and I really hope you can point me in one solid direction! I went drag racing the other night in my 2003 350Z. Everything was fine the whole night. Oil pressure was good, temp. was good, voltage was good. I got knocked out the second round, and finally turned my car off after about four hours and watched for about an hour. I decided to leave and drove about 4-5 miles up the road and noticed my temp. gauge was high but not "spiked". It was close to the line under the H but not quite on it. Needless to say I turned the car off and let it cool down. When it was cold enough I drove about half a mile up the road to a well lit area and there I stayed until help arrived. We put more water in the car thinking there was a hole in the radiator and I started to the house, but not even a mile up the road it started to spike again so I just parked it and cut it off. Attempted to put more water in it, but ended up towing. I changed the Thermostat because the next morning I was letting it idle and feeling the hoses, the radiator hose was cold while the others were very hot. So I got that done. I noticed that there were bubbles coming out the radiator and eventually the reservoir would start to fill up. There was also very little white smoke coming from the exhaust. I turned the vehicle off, let it cool down for about two hours and did it again. this time there was almost no white smoke and took a much longer time for the engine to start overheating, and it would only do that when I put it at 2,000 or so rpms. So i put more water in it as the water in the radiator would disappear but eventually gave up and let it sit. I worked the nerve to go back out there to mess with it some more and this time it took a very long time to get hot. I even test drove it around the apartment to see how it would react and everything seemed fine. So i let it sit for 30 minutes then took for a drive 3 miles up the road, and all seemed well until I got to the end of my trip it started overheating quickly again. But when it idles it will cool itself off and go back to regular temp. I seen one little puff of white smoke and that was it so that seems to be disappearing. OK so I thought it would have been a head gasket. but wouldn't you hear that? Wouldn't that sound muffled, or just nasty? I don't seem to be losing any water either.... I started the car several times but only twice did the car sound rough starting. All the other times it was fine. When it idles it sounds normal, even when I drive it, there is no difference... I'm stumped at this point and dont know what else to do other than trying to "bleed" the coolant system???? I dont see any leaks anywhere either. I know this is a lot, but I wanted to give you something with as much detail as possible. I need to have this fixed in the next two days if possible. So I'll be looking forward to your response. and Thank you ahead of time!

 

Well it def has air pockets in the cooling system so that is the first place to start.There is a bleeder port on the pass side near the battery box and you will have to bleed the system multiple times to get the air out.Start there and let us know what happens next.

 

Check out this site...

http://crackaddict.com/~flynn/howtos...amco.howto.htm

At the bottom of the install instructions are some on how to bleed the system. Once you get air in the Z's cooling system, it's not trivial to get it back out.

 

Welcome. 6 seasons of drag racing and never had a heat problem. So racing is not the cause.

The thermostat is the culprit. You changed it.

My concern is white smoke. Is the coolant level OK? Are you using (burning) coolant?

 

+1. you have to bleed the air out of the system. If you follow the service manual instructions for doing it, it can take a couple hours to complete. bringing the car up to temp, hold the revs at 3K rpm, idle, bring the revs up again, idle, etc. then, shut the motor down and let cool......wait....wait...wait until cool. then add more coolant/water via the bleed valve. close up and start the procedure all over again. you may have to do it several times to get all the air out.

 

Recommendation on "cooling down". Don't shut the engine off, turn the heater on high. This will pull the heat out of the engine. Of course, if the thermostat is toast this may not work.
I did this on a car that I ran into a telephone pole, changing the radiator shape from flat to V-shaped with a monster hole in the bottom of the radiator. In about 10 miles, it never overheated.

 

yup..ive never had a problem with overheating..id say bleed it and see where that gets u

 

there is coolant in the car?

 

I like the responses I'm getting. My dad and a few friends said they think it could be the head gasket due to the white smoke. But there was nothing else leading to that. I am about to go bleed the system now the rain stopped this morning. There is coolant in the car too lol!!!!!!! And I did change the thermostat. I'll keep you guys updated and let you know how it goes!

 

I drove my car for about ten miles after bleeding the system twice. the fans kicked on and all was good. when i pulled into my apartment complex and parked the gauge started to rise slowly. so better than before. i went to get the oil changed. before it would overheat in the matter of 2 miles. its getting much better and the white smoke is pretty much all gone. gonna run sea fome or whatever through it to see if it helps with the rough starts

 

rough starts? and white smoke? id say it might be a head gasket. Also how did you add water if the water level was normal?

 

Everything is great with the car now. I bleed the system correctly and did it three times and its all back to normal I also ran sea foam through the system and it even sounds better! there is no more white smoke that I can see. But the only thing left is the rough start. But its odd because it only has a rough start on a hot engine......... Never does it have problems when starting on a cold engine..... any thoughts on this one????

 

tmsurla since you are new to the forums give me a call. ill pm you my number.