Was the front of the car raised up? You need the ramps to raise the radiator higher than your heater core. This is why the heat doesn't work. Air in the heater core.

 

It wasnt but I got some ramps and raised it, and tried again, same problem with overflowing making it very hard to continue doing it. There were occasional bubbles with a lot of revs but i had to keep shutting it off every few minutes. And I'm not sure I'm able to get it high enough. After doing this for about an hour, constantly turning on and off my car cause of the overflow, still no hot air blowing.

Since I'm able to drive sometimes, and the overheating problem only presents itself sporadically, could it mean there is air getting in somewhere? There were occasional large bubbles coming out about 30 seconds after killing the ignition.

If it's really still an air bubble trapped somewhere I may have to try to take it somewhere for them to get it out better than I can... Any suggestions are greatly appreciated.

 

Are you opening the bleeder valve on the heater hose? I'm going to guess no.

 

IN the FSM ( HERE ) http://www.nicoclub.com/FSM/350Z/
CO-9 shows you a purrdy pix of where the heater core air bleed cap is......

 

If you're getting all of the air out and the cooling system is getting new air introduced into it, there's only one cause for that... head gasket.

 

He has no heat that means he still has air.

OP you still have air in the system.

 

Thank you guys, yes I have had the relief cap open for all of these procedures..

My coolant is free of oil and vice versa, no white smoke in the exhaust, no white particles in the oil chambers, etc. I bought the block test kit with fluid but due to the problem of the coolant coming out of the radiator cap I have not been able to test it properly.

Possibly I'm not able to raise it high enough then, these are the ramps I have: http://www.walmart.com/ip/RhinoRamps-Black/19526658 . Also when I start driving the heat kicks on and works but as soon as I slow down it blows cold again (that's somewhat ironic to me). It seems I will have to take it to a mechanic who can bleed it properly, since I'm not having any luck.

 

Forget the ramps. Use a jack. Jack stands are like 15 bux at harbor freight.

 

You seem to still have air in the heater core. Whether it's just not being purged or it's blocked by something else is the question. I would try fitting and filling the funnel until the level is well above the engine, then release the return hose from the heater and see if coolant comes out of the core. Do it with the engine cool and off. If it does, fine, let it flow until all the bubbles clear. If not, well you have an issue.


If you still have air in the coolant circuit your radiator will never reach proper pressure and your coolant will boil.


Other options. Not reading back all the way, but was the water pump installed correctly? Did you use any kind of "stop leak" in the system?


Finally, all else fails take it to a dealer. You risk doing expensive damage if you keep overheating.

 

Hey guys, sorry for the hiatus. I was finally starting to get some heat in the system when I accidentally tore through the heater hose at the bleeder valve, as it was hot and a really old hose. I got a new one, had my old mechanic put it in, and told him you need to be very careful to bleed it properly, and he used his own funnel, and said he still thinks its my head gasket.

I said thanks and drove off, what do you know, it overheated. So I bled it again and this time was able to drive much further, all the way home, so I assumed he's just not that good at bleeding it and keeps getting air into my car.

Then I keep bleeding and occasionally I will get hot air blowing, but then after a while its cool again, so I just assume I'm completely inept at bleeding my car, and decide to take it to a different shop, where I know they have a vaccuum to get all the air out and flush the system. At this point, it was not looking good, because just yesterday it started blowing a little bit of white smoke from the exhaust, and not idling properly (low and misfiring), and a code came up (it was doing none of this before). When he ran the code, it was P0300, random cylinder misfire..

So, just wanted to conclude with you guys, that it turned out to be a head gasket issue. Of course, I'll never really know if it was this all along, or if I caused it while trying to bleed it, or if it was even this way when I bought the car 3 years ago and there was some nice sealant in there. Either way. I really kept wishing it was just as simple as air but all hope is gone now. I know a 350z specialist not too far from me that I will take it to and see how much he wants to put in a new head gasket, or if it's even worth it for an older model at this point.

Thanks for everybody's help. Cheers