what's this noise?
 

It's kind of hard to hear it but there's a high pitched whining noise that comes from the engine area... Im having a hard time pinpointing the actual cause/location of it.. I was gonna post a video but the file type isn't uploadable here :/

Post it to YouTube and put the link in here.

Congrats on your new supercharger! 😂


I would say get up close and try to locate where the sound is coming from. It actually sounds like a worn bearing though.

So it should be the loudest around the oil pan area?

Oh and sometimes the sound goes away after the cars been warmed up , sometimes it takes a pretty long time, it's been pretty sporadic

Sounds like a pulley bearing to me.

Idk I took the power steering belt off the other day and then started the car because I had thought it might be the p/s pump but it still made the noise.. so if it is a pulley itd would only be one related to the compressor... I'll take that belt off and give it a try tho

Try spraying some water on the belt as its spinning. If theres any change in sound then thats what it is.

You have two sounds in that video, first is the "swish swish swish swish swish" sound coming from the engine bay, that is almost definitely a pulley bearing starting to fail. Normally it's either the one idler or two belt tensioner pulleys. They only last about 100k before needing to be replaced. The idler is a lot more robust and it can make it to 200k but those tensioners definitely cannot.

The second sound is that steady high pitch coil whine sound. Possibly a vacuum leak? Have you had your intake plenum off lately? If you pinch the oil fill neck between the upper and lower plenum it makes that same sound.

I'm not sure on the design of the internals of the Nissan alternators, but the high pitch noise is usually an indication of the diodes failing in the alternator internal voltage regulator circuit. I had that issue with cars I have owned in the past {Mercury Monarch and Eagle Premier). You can remove the alternator and take it to AutoZone, they will test it free of charge.

When you say tensioner pulleys I'm pretty sure I understand what you mean but the manual 3 pulleys labeled as tensioner pulleys so I'm assuming those are the pulleys you're referring to.

And yea I actually did just have my intake plenum off but it isn't the cause for the noise because it had the noise before I took it off lol... That being said idk if I used a new gasket when I had taken the manifold off like a year ago...

The gaskets are reusable so that's probably not the issue as long as it was all torqued back down.

The manual calls all three of the pulleys tensioners, but technically only the two on the bottom with the adjuster nut are the "tensioners", the one on the top is technically an "idler" pulley because it's not driving anything and it has no adjustment.