Knock sensor and MIL

NissanTxUser · Oct 22nd, 2007, 06:06 PM

Hi,

Can someone please help me? It is 96 Altima with 99,000 miles.

For last 2 years I had code P0325 showing up in OBDII diagnostics - but 'Check Engine Light' did not come on. Yesterday the MIL light came on and does not go away. Codes are P0325 (Knock sensor) and P0310 (Cylinder 10 misfire). What could be the problem?

The car has been running ok - it does give some knock and slow to get acceleration the first few minutes. But, what I have been doing is let it idle for a few minutes in the beginning and the knock seems to go away and power seems to be ok after that. I have been using premium gas every now and then.

1. How can I get a cylinder 10 misfire when there are fewer cylinders?

2. Do i need to change the Knock sensor? Or, I can continue to keep driving?

My guess is that replacing the knock sensor is a high cost proposition. I had the knock sensor supposedly replaced by a reputed repair shop 2 years back along with CAM sensor - but the code P0325 has always been there and had problems with inspections. Last time the repair shop said thay had oil in distributor and cleaned it up that ultimately made the MIL to go away probably.

Thanks
NissanTXUser

jserrano · Oct 23rd, 2007, 08:45 AM

There is no such thing as a P0310 for the Altima. It was likely misinterpreted and should have been a P0301 - which is a cylinder #1 misfire. The #1 cylinder is the one closest to the passenger side fender. The reason your car is slow to pick up is because of that misfire. The likely causes are, the #1 spark plug or wire, the distributor cap, the #1 fuel injector, or a intake gasket leak around #1. If you haven't done a tune-up in ages then that should be your #1 goal.

The P0325 is a very typical problem in Nissan engines. The MIL will NOT come on because of it but it will show up when another one has tripped the Check Engine Light. Unless the knock sensor (KS) has a loose wire or something similar, then it is time to replace it with a brand new sensor. The previous shop probably didn't do that. Even with a bad KS or without one the engine will perform just fine. Just hope you never get an actual engine knock or you'll hurt the engine.

The oil in the distributor cannot just be simply cleaned away. Once is leaks oil it will continue to do it for eternity. Only a brand new expensive OEM replacement will guarantee the fix. Otherwise, be ready to replace it repeatedly if you use a rebuild.

Good luck.