I know there have been lots of threads on knock sensor relocation for non-supercharged Xterras to the intake manifold.

I have a 2003 supercharged X, and I am too lazy and cheap to replace at the actual location, so I have been running 94 on the resistor mod for a while now. While doing an oil change, I found a good location on the block, right below the mount for the power steering pump, but it is an M10x1.5 threaded hole.

I have never seen a stock knock sensor, but from the pictures, I doubt it has a 10mm bore hole in it. I have tried at my local parts store to get them to show me one, but they are always a "special order" item, and they don't have them in stock.

So my questions are:

1) Does anyone know of a knock sensor that will work on my 03 S/C X with a 10mm bore hole?

2) What is the difference between the knock sensors that look the same but have different costs/part numbers (for example the 99 maxima and 00-04 xterra)? Characteristic resistance/impedance? Something else?

3) When I do decide to just replace at the stock location, what parts (and part numbers) will I need? I imagine there is an intake plenum gasket that needs to be replaced as well.

4) If I measure the electrical resistance across the leads on the knock sensor, will I find a fairly consistent value across different knock sensors?

5) Does anyone know of a website that has specification sheets on aftermarket knock sensors? I have looked on Delphi, AC Delco, Bosch, Airtex, Beck/Arnley, and Standard and found nothing.

Thanks in advance
Dave Cameron

If you're sure that the location you found will work, why not find a stud, with diff threads on each end to fit the needs? I know I have read a few posts where they have tried a few locations before finding the one that does work, since diff locations will pick up different vibrations and may send the KS code even when no problem is present.

I dont know what the bore hole size was on mine, but if I recall it was a 10mm (possible 12mm but no bigger) socket used to remove it. And yeah, I wish I would have replace mine when I swapped the engine out, just forgot about it. Gaskets, yes. Intake and plenum etc.... check this site, easiest place to find all that you need, I had a bitch of a time trying to find anyone local that had what I needed and had to get them from this site, but your area may have more options. At least it will show you every part you might need.

sorry I cant be of more help with your other questions, but most of what I had to do is still pretty fresh in my head if you have any questions later on.

I have looked around for such a beast (stud with different sizes) and have not found a local source. Any ideas? Even if I found one, how would I tighten it?

When I say bore hole, I mean the diameter of the thread part of the bolt that holds the knock sensor in (and therefore the diameter of the hole in the knock sensor), not the size of the wrench needed to loosen it. I imagine that the knock sensors that come stock use an M6 or M8 bolt (6mm in diameter or 8mm in diameter). My M10x1.5 bolt uses a 17mm wrench to loosen it (although 14mm head size is not uncommon).

I won't know for sure if this location will work until I try it.

Thanks for your reply.

Dave

Knock sensors are piezoelectric crystals that create voltage from pressure (vibration), and are tuned/calibrated for the application. I suppose it's possible to swap out one for another while changing the location and have it work, but that would involve some serious engineering or extreme luck to pull off. I don't know what the resistance would look like on a KS, but I doubt it would tell you much about it.

If you're wanting to relocate it to a new sized hole, I would think the easiest thing to do would be to either a) weld two nuts together, one that fits the KS and one that fits a stud that fits into the hole, or b) weld a stud that fits the hole onto a nut that fits the KS.

That's about all I can help with. Good luck.

yeah, I knew what you ment about the bore size, was just trying to give you a bit of a reference to what size the hole would be by mentioning the socket size that takes it off. sad part is, before the XOC site met its death, there were a few posts on there, with complete details on how and where to put the KS as well as what other model KS's worked for the relocation process. I was actually hoping to do it on mine, but the info is now gone., hopefuly one of the ppl that had it posted on the old site might come along and redo the post........

http://www.nexterra.org/forum/viewtopic.php?t=2071&highlight=knock+sensor
Try this one.

If you're just going to hinkify it, why not just stick with the resistor mod and continue to run high octane fuel? Same difference, just cheaper and easier. Eventually, if you're going to replace the original in the original spot, then just spend that money at that time, instead of wasting time and money now.