Kuroshiito

This might be a common problem but is bothering me a lot, I have a 04 350z track edition and a few weeks ago I decided to change my coolant, since it was overheating sometimes.

Now that I changed the coolant (I didn’t notice it before changing my coolant) my lower hose is cold, and my fans aren’t going off anymore even after 30 min idle (all this after a ride).

I already bled the system many times, and still have the same problem. I also tried to warm up the car before going for a ride, and when I do that, the lower hose gets a little hot, but after I go for a 10 min ride or so, my lower hose gets cold again and my fans kicks in.

I haven’t changed my thermostat because I don’t want to replace it if it’s not needed. Since I know it opens up, I know it’s working, but not sure if it gets stuck when the pressure gets higher. So I was considering changing it.

What you guys think I should do? Anyone know what could this be?

Btw, I am using destilled water right now, cause I was flushing the system, and I want to make sure before filling the radiator with new coolant that everything is ok in the system, cause it would be a waste of coolant if I had to replace anything.

I don’t know if just running destilled water might be bad for the system, so tell me if I’m doing something wrong. Thanks!

tcode

iTrader: (7)

You should use spill free funnel for air bleeding and if you cannot bleed the system, a head gasket is blown 99%.

Kuroshiito

Thanks for the reply. I did use it, I have no more air in the system, at least That’s what it looks like.

And I will look more about that, I haven’t research about the head gasket yet.

bealljk

iTrader: (13)

Does the car continue to overheat?

Does coolant push-out of the overflow tank?

Kuroshiito

When I have the heater on, it doesn’t, but if I turn it off it will increase the heat slowly, btw I have only tried this with a lot of traffic, so was going gas, stop, gas, stop, and so. I think this have to do a lot with it.

And it did it once, before I changed the coolant. But I didn’t have any white smoke from the exhaust. Right now I have destilled water on it and it never puked.

I checked some forums about the blown head gasket, And I didn’t saw any smoke or had lack on power when driving. Also It starts up pretty fast, so I doubt that water is leaking to the cylinders.

coletrickle74

iTrader: (1)

Thermostat or not bled enough. Start with those before determining its a head gasket.

bealljk

iTrader: (13)

what cole said ... swap out the thermostat and bleed, rebleed, and bleed, then bleed, then rebleed, then bleed...

Kuroshiito

I see, I’ll try that then before anything else, what thermostat would you guys recommend? I was thinking in the OEM one from Amazon.

bealljk

iTrader: (13)

It doesnt matter ... a auto parts store OEM equivilent is going to be fine. I have a few OEM thermostats in my parts box if you want it throw me a little cash to cover shipping and you can have it.

PM me if you are interested.

260DET

Just wondering if everyone is on the same page as far as bleeding technique goes, it might be an idea if someone who has bleeding experience to spell out what it involves.

coletrickle74

iTrader: (1)

To be honest, I have never had to necessarily ever bleed a cooling system. I've always just run the car/truck with the radiator cap removed. I did this when I did the radiator and it was done pretty quick. I did check the bleeder and it confirmed there was no air in there.

bealljk

iTrader: (13)

My setup is one-off and I have installed bleeder ports to make bleeding easy.

jimbucks

If it were me, I'd pull the thermostat and not replace it. Sometimes entire runs of thermostats are bad, and simply replacing a bad one with another bad one will mislead you.

bealljk

iTrader: (13)

The thermos I have came from blocks that spun bearings ... you could always boil the thermostat to ensure its function.