You can unplug the sensor first and it should turn your fans on.

I had a water pump go bad in my engine around 120K miles. If you're not hearing any weird noises coming from the engine bay it's fine. The pump is driven by the timing chain, so the faster you rev your engine the water pump is going right along with it. In my case the bearings were seizing, so it still worked without issue, but it sounded like my car was screaming. There are two gaskets that tend to leak on the water pump, but if you are not seeing any coolant/oil mixed together it's probably fine.

Did anyone work on your cooling system prior to removing your thermostat to test? Honestly, sounds like you have an air pocket in there and removing the thermostat you introduced more air in.

Another possibility is maybe you have a leak somewhere and the reservoir ran empty and sucked some air in. How's the coolant level?

 

And when he says coolant level he means the level in the radiator itself, not the overflow tank with the full and low marks.

 

I read somewhere online saying that a way to test water pump is turn heater on full blast.. And if it blows warm then you're good to go on wp... If not, it's bad...?

 

The water pump is under the timing cover and the timing chain wraps around it. So, whenever the engine is going the water pump is running and pushing coolant through. If you don't hear any weird noises while the car is running your wp is most likely fine.

I still think you have air in the system or the sensor is going bad.

Are losing any coolant at all? Open the engine fill cap and see if the oil looks like chocolate milk.

 

I am trying to check sensor, but can't find it lol, is it easily accessible??

And I'm not losing coolant.. The over fill tank is still full.

 

Towards the back of the engine near the firewall on the metal coolant pipe there is a sensor in the pipe. That is the coolant temp sensor you might be able to get it out easily.

Open the radiator cap also and see how much coolant there is (when it's cold).

 

So when the cap is removed when cold the coolant can't be seen. Then again how the radiator is positioned , the cap part isn't vertical to the radiator so I can't see into radiator to see proper level.. However when car warmed up, the coolant came up to the radiator cap.. But didn't move, coolant was still.

 

I could be wrong, but I'm pretty sure it should be close to the top even when it's cold. It gets sucked out of the top through the hose. Try adding some distilled water and/or Nissan coolant if you have any to top it off. Then fill the overflow tank about halfway between the min and max lines.

You'll probably still need to burp out any air in the system, which I think is the problem.

You can also head down to AutoZone and rent a block tester for 25 bucks. It's a cone looking thing you put in the radiator hole while the car is running. It checks for exhausts gases in the coolant and if it turns yellow or green means your head gasket is blown. But, if you're not having any power loss or anything might not be a problem. I'd test it out for piece of mind though....

According to AllData you can measure that sensor at pin 73 of the ECM and should read the following:

-10 C 4.4v 7.0-11.4 Ohms
20 C 3.5v 2.1-2.9 Ohms
50 C 2.2v .66 - 1.0 Ohms
90 C .9v .236 - .260 Ohms

Do you have an ODB-II reader? I'd buy one of those and Torque App then you can monitor everything with your phone. I've used that with pretty good success on my car.

 

Hey so i know this thread is over 10 years old but what was the issue? im having the same thing. Im having a mechanic change my waterpump and radiator (since the radiator blew tiny holes int it) but im scared there might be a faulty headgasket. I asked him to check but im scared

 

I'm having an overheating issue now as well on my 05 6mt coupe with 29,000 on it. I cant get the lower radiator hose to get to a warm temp. All my Z1 hoses are good, hard coolant lines are good, mishimoto thermostat is like brand new, rad shows no leaks, WP shows no signs of fluids leaking between the timing covers, heat blows hot, system seems to be free of air idling with the spill free funnel on to burp it but the thermo wont open and the fans wont come on and the coolant in the funnel reaches a steam almost looking like its reaching a boiling point as I shut the car off. The gauge in the car sits at normal as well.... head ache!!

 

 

Yep, it has a brand new thermostat in.

 

What brand thermostat? Are your fans working?

 

I just put a mishimoto in. The fans are not kicking on. Oddly they did come on once during one attempted to refill/burp at a very slow speed...close to a rate you can spin them with your finger.

 

Turn your A/C on and the fans should kick on automatically to verify their operation. Just because the part is new doesn't mean it's not defective too. I can't remember if they come on high or low speed though with the A/C running you'd have to look in the FSM. My original fans were spinning too slow at high, because the motors wore out. Try revving it with the funnel on as well to work out any air bubbles.