It's been a while since I posted here, first of all I ended up keeping the Z, got a new job last minute and all worked out ok.
I finally made it back to the track first time in 1 1/2 years last weekend and had a blast...how missed it.

Now here's my question:

this does not happen in the mornings when I first leave for work
it happens when I leave work when the car is cold but was out in the sun for 8 hours.
Basically when I start the car after about 4 minutes when I'm idling (stop and go traffic for example) the temperature gauge goes way up and stays there. when I then start driving again it goes down to the middle and stays there and all is fine.
I checked my coolant and oil and it all looks fine, the HKS Navigator shows about 105 water temperature which is normal as well.
I have a feeling that my fans don't want to come on in the beginning (they are running by the time I get home).

Any ideas what this could be? I'm still low on budget so I kinda want to have an idea of what the problem is before I bring it to a shop.

thanks

PS> totally unrelated but I also finally got my clutch working again (sticky clutch pedal...) I ended up needing a new slave cylinder...it's working perfect now

 

it does sound like the fans if it cools down while moving

 

if it's the fans and they are running after a bit any idea on what could cause them not to start up with the car?

 

it could be a relay, maybe it is not kicking into hi speed, are you running the a/c at the time it overheats?

 

yes, but even if I turn it off it doesn't change

 

Turn your heat on full blast when your driving and see if it goes down.

 

the problem is that once it overheats turning the a/c off wont have a big impact until it cools down with movement or the slow speed fan.

to verify this see if the fans change speed while you turn the ac on and off

 

+1
First check for heat in the vents. If there is no heat, or luke warm, you probably have some residual air in the cooling system...maybe from the track day.

 

problem is that the moment I start driving normally the gauge goes back to normal so putting the heater on wouldn't show anything.
there's plenty of heat coming out of the vents when I have the heater on (once the car is warmed up)
Is there a way to check if it's a relay that's being sluggish?

 

Have you confirmed that both fans are working?

 

first thing i would do is bleed the system. By bleeding it, you will verify that there is no air (air wont trigger a fan to come on) and it will verify that the fans are working correctly..

 

Bleed it and rebleed it, these cars are a PITA

 

thermostat about to fail. the time range sounds very close to a lagging thermostat and the spring is loosing it's ability to change with heat to open. only reason for this to happen. if it continues to happen after it is warmed up and driving for awhile and heats up again at a stop, then yes, you have an air bubble, or fans not coming on.

 

quick update.

I'm starting to think I do have some air bubbles.
Yesterday on my way to work I turned up the heat full blast and it took a minute then it got hot...the car was still cold though so I wasn't worried.

Today it was different.
I started driving on the fwy for about 10 minutes and turned the heat up again, only cold air even after a minute and the gauge went way up, I turned off the heater and turned it back on, a bit of warm air and then cold again and the gauge dropped and went up again.
I turned the heater off and then on again and this time I got full blast of hot air and the gauge went down immediately. After that I had no more problems.

So I guess I need to bleed the system...
Any idea how I suddenly got air in there, it happened right after the track day btw.

Could this be an electrical problem since it eventually started working again and it seems to only happen when I first start up the car (within 10 minutes usually)

Anything else I should check?

thanks

 

Hey Thomas! Long time no talk, Jason and I were just talking about you the other day.

Glad all is well, maybe I will see you at irwindale one of these nights if you still go there....

105 is a bit high, I usually don't like to go over 100. Does sound like their is air in the system, I would purge it as per shop manual specs, a few times - to make sure you get all the air out. Hopefully this will fix your problem.

-George

 

It is the same exact problem i just had you have to bleed the cooling system.I only just replaced my plenum and i thought i was ok but it lost some coolant and i got an air pocket. Well i bled the system and thought i was ok but the temp gauge still would go up so i bled it 3 more times and now its ok.

 

Hey George, what up...

I'm planning on going to Irwindale tomorrow (5/8)


So it turns out I was way low on coolant...even though the overflow tank was filled ok, once I started adding fluids to the radiator tank I poured in over a liter before it filled up. I repeated the process three times and so far so good no more overheating and the vent temperature goes hot immediately now.

My only concern is that I was never able to get fluid coming out of the air releave valve. So I'm sure there's probably still more air in there but I didn't have a place to have the car lifted up a bit.
I'm going to try again tonight with the front lifted up, hopefully that will do it.

Since I've never done this process before I am/was a little concerned that maybe I opened the wrong vent, but I can't find anything remotely similar to a release valve in the neighbourhood.

it's the green screw-on that is labeled Evap Port in between the engine and the battery compartment, am I correct?

Any other ideas on why I'm not getting to have fluids come out of that sucka even though the radiator port and the overflow tank are completely filled?

Thanks

 

Tom if I remember correctly you have a aps tt. The T fitting if it is still there should be next the fitting that feeds the coolant to your turbos. It is located on the passanger side firewall near the battery. You can also go to your locle auto parts store and get the funnel kit and use that instead. I've used this for my Z sincee TT'ing it back in 05 and it works fine with no mess.

 

oops, so what the heck is the evap thingie I opened then?

I have to look for that t-fitting.

So if I use the Funnel I don't need to remove the line from the t-fitting?

 

No you don't. If the fitting is there you open it with a phillips screw driver tip. If not use the kit. The funnel kit comes with all the adapters to fit the radiator and a T handle plug for the excess coolant in the funnel so you don't make a mess. When you do this don't put to much coolant in the funnel to start or it will over flow as it expands. Ithink there is a diy about this somewhere here.