# A single and hidden P0325 on 97 Maxima



## saig (Aug 16, 2007)

Hi,

Last night I pulled the code P0325-Knock Sensor Bank 1. Last week in 95 degree weather, the car was overheat while driving with AC on. A weird thing is the Temperature Gauge shot up. After I turned off the AC and put on maximum heat, the needle dropped down to 9 o'clock position. Should it change gradually up and down? 

After this, I changed new coolant, oil/filter (synthetic and nissan filter) and a new thermostat. The car is not overheat now. But it is running hot and the engine sounds like knocking. I always fill up with 92 Octane from SA. The car is not responsive after into 30-40 minutes drive.

So what should I look for?

Engine Coolant Temperature Sensor?
EGR valve?

Thanks

Saig


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## smj999smj (Jan 1, 2006)

Did you use a Nissan thermostat? Is the radiator cooling fan working? Is there any restriction of airflow through the AC condensor and radiator cores? Condition of radiator (flow tested)? Did you purge the air out of the cooling system?

A hot running engine will cause the engine to knock. Sounds like the gauge and knock sensor are working properly.


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## saig (Aug 16, 2007)

Yes, I use new Nissan thermostat. Both the radiator fans are working. I don't know how to purge the air. When changing the coolant I followed this guide: motorvate.ca v2.0 - *THE* DIY Maxima Website. It did not mention about purging air. Do you know how to do it with the Maxima 97?

Thanks smj999smj
Saig


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## smj999smj (Jan 1, 2006)

Nissan later revised the procedure, using a coolant system tool that puts the system under a vacuum and allows the vacuum to suck in the coolant (thus, no air pockets). It's nice to have the tool, but not necessary...especially since you already have installed the coolant. There should be an air bleed valve on the engine...I believe it's near the coolant temp sensor, but don't quote me. With the engine cool and the radiator cap removed, loosen the air bleed screw and purge out the air until you get a constant stream of coolant. At this point, the engine should be run until all of the air bubbles are out of the coolant. It's best if you can raise the front end of the car up slightly. Run the engine without the cap until the thermostat opens and the air bubbles stop. The best way to do this is with a Lisle 2qt. funnel kit with rad. adapters. It allows you to securely attach the funnel to the radiator neck and fill the coolant system until it is about 1/3-1/2 up the funnel. Runn the engine and you can more easily observe the coolant and allows for less mess when the coolant surges as it expands and contracts. The funnel kit runs about $20.


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