Failure of the oil pressure sending unit appears to be a common issue on 2005 and 2006 Xterras. I noticed yesterday the something was wrong with the oil pressure reading on my 2005 that has 107K miles. A little research here and across the internet confirmed this to be a common problem.
High oil pressure reading. In my case, the oil pressure gauge was pegged at high when the engine was running. With the key turned on and the engine not running, the gauge indicated the pressure as about 3/4 of the way up the scale.
Replace the oil pressure sending unit. I believe Nissan describes it as an Oil
Pressure Sensor. The p/n for my 2005 is 25070-CD00A. The out the door price from the local dealer was about $85.
SIMPLE. It took me less than fifteen minutes from start to finish.
A 15/16" (or 24mm) wrench or deep socket, a flashlight, pipe thread sealant, paper towels.
- Locate sending unit. It is located on the passenger side of the engine directly below the alternator and behind the rack and pinion. It is easily visible from underneath the vehicle. No issues with access on my 2005 S with a Shrock bumper and front skid.
- Remove the wiring harness connector. Unlike some, this is an easy connector to remove with your fingers.
- Remove the old sending unit. I used the open end of a 15/16 wrench. As you finish removing the sensor - watch out for oil! A small gusher came out when I removed my sending unit...not a lot...less than a 1/4 cup, but it tasted terrible.
- Clean up the oil mess.
- Apply thread sealant to the new sensor. I would strongly suggest not using teflon tape for a couple of reasons. It can interfere with getting a good electric ground which is required. There is also a (small) risk that strings of teflon tape will get into the oil galleries and cause some type of mayhem. I used a tube of white paste thread sealant. If you are old school, Permatex #2 is another good choice.
- Install the new sensor. Do not over-tighten. The sensor has a tapered pipe thread so not a lot of torque is required to get an oil tight seal.
- Reconnect the wire harness connector. If you are anal, use some dielectric grease to keep out dust and moisture.
- Start the engine and confirm the gauge is reading properly.
- Check for leaks and check the oil level. I had no leaks and did not need to add oil.