While parked today my 05 Z (112k miles) over heated and was pegging the temp needle. The only reason I even noticed was the a/c stopped working and was blowing hot air. I turned the car off, went in walmart and came back and the car was reluctant to start and when I did get it started it was missing and sputtering. I got it home with no more over heating issues or missing issues (guess the intake temps were so high it just didn't want to run correctly).

I let it sit in the driveway running to recreate the problem and it turns out the driver side fan doesn't kick on at all, iirc there are two fan speeds as well. The passenger side fan will run but at a low speed but it can't cool enough to keep the car from over heating at all.

Is there a temp switch that operates the other fan? I turned the car off and spun the drivers side fan... its not locked up and it spins freely so I don't think it's bad.

 

Not locked up doesn't mean it's bad.

Both will come on at low speed when the A/C is on. They will switch to high speed when engine temps rise enough.

You said it was switching to high speed mode right? Try running direct power to the non-working one, see if it comes on. If not, replace your fans.

Basic diagnostics here...

 

Only one fan runs at a constant low speed (passenger). Drivers side fan never comes on even with a/c on.

Are both fans needing replaced since the the only one running doesn't switch to high speed?

 

The fan is one unit but I believe each fan can be replaced. That said, I would go the ebay route and buy used OEM fans there from a reputable seller. They aren't expensive and probably a small fraction of what the dealer would charge you. I would also stay away from aftermarket fans, the OEM ones are solid overall.

If you must have new, go to courtesy parts online and order them there. If one fan comes on, the other should as well.

 

I'm now having the same problem; what was the fix?

 

One of my fans was dead. Bought a Mishimoto fan shroud...

Problem solved.

 

Thanks, cost and part #?

 

OK found some on ebay, is it a direct replacement like OEM? looks like the wiring is not OEM.

 

No it is not oem wiring... there is a schematic here on my350z if you search. It's an easy install if you are handy with electrical.

http://www.b2autodesigns.com/product...roducts_id=469

Free shipping from B2 Auto

 

If it's the fans, you generally have one of two options. Take the bushes out of the fans, clean, and replace, usually does the trick or replace the fan motors.

Get it sorted soon, or you may end up having to pay out for a head gasket as well.

 

Thanks everyone for the help

 

It was the left fan, spun it by hand and it started to work very slow. I was going to buy the Mishimoto but went with Dorman instead. ordered today.

Thanks again everyone

 

Wow might of had the same problem as you. My Z overheated today too.
I didn't check fans visually.
I had taken a ride and then sat in car on phone in just 80 degree weather for 30 min with AC on at idle then went inside for 5 minutes with car turned off then back in those 5 minutes and I couldn't get the car started, same thing as you, it sputtered a few seconds and stalled out.
I tried starting 2 more times with no avail and noticed temp was at half way point after being off for a bit after the idling.

Checked for leaks, there were none but overflow reservoir was almost to the lid about an inch from overflow and in the past I know the level was at the line. So I figured it was the thermostat since it was not leaking, new belts and the I heard the fans so I figured they were OK now Im going to have to check fans cause I tested the thermostat in 180 degree water and she opened within
15 seconds so at least shes getting a flush and new silicone hoses but I hope the fan is all it ends up being.

Plus ran test only code that came back was the MAF sensor P0113 code but it was disconnected when I ran the test so that will be tested later also. Ill post my findings tomm or the next day ttyl.