Knock Sensor Torque Setting

[wixer]

As title says, I've been looking through the on line workshop manual but I can't find reference to the torque setting for the knock sensors mounted to the cylinder block. Anyone know (Kaz ?) ?

[goldnsx]

What size has the screw?

[wixer]

Will have to look in garage but I think it was a 19mm spanner that fits and thread diameter is probably 10 or 12mm.

[goldnsx]

You get an idea of how much it's torqued if you remind how much force it needed to be removed. A 19 mm screw is normally 95 Nm in usual cases but as I've never had a knock sensor out, so I can't figure how it looks. If it's a unit that looks like an oil pressure sensor gauge unit which is also mounted to the engine then the torque is much lower! As they're exposed to vibration the torque might be higher. If you can't find a torque setting I'd go with a reasonable torque on the lower end but use locktite blue on the threads.

Not sure if that is of any help...

[Pride]

Some good ideas goldnsx, there are a few web sites with maximum torque settings depending on the size of thread you’re torqueing but here’s one I found for you:

http://electronicfilters.tpub.com/TM-10-4330-237-13P/css/TM-10-4330-237-13P_105.htm

Good luck Wixer.

[NSXGB]

Do you know the spec of the knock sensor?
See here: http://www.bosch-motorsport.de/content/downloads/Products/resources/23177848715/en/pdf/Knock_Sensor_KS4-P_Datasheet_51_en_23176461835.pdf

[wixer]

Thanks for all the replies so far guys, very useful info.

Simon, part number for knock sensor is 30530-PR7-A01 number 3 on here https://www.oemacuraparts.com/auto-parts/1991/acura/nsx-coupe/nsx-trim/5-speed-manual-engine/engine-cat/engine-wire-harness-clamp-scat

Cheers.

[NSXGB]

I was wondering more if it was a Bosh part (more likely Denso I suppose) or if Bosch sold an equivalent, you could maybe check using the link I posted....

[wixer]

Not sure which supplier makes it. I have two new ones ready to go in.

Spanner size is 27mm, thread size is M12, probably 1.5mm pitch but I haven't measured it yet.

[Pride]

Having looked where this knock sensor fits I think just nipping it up firmly on a dry thread is all you would need to safely install it.

[wixer]

Been thinking the same thing Pride but equally, due to their location, I don't want them coming loose and having to strip the entire top end down, just to re-tighten.

[wixer]

13251

Pic of sensor.

[Kaz-kzukNA1]

30Nm.

However, if you managed removing the existing one using 19mm spanner, we are talking about different thing as there is no way you can fit it.
Unless Honda changed the sensor spec long time ago, you will need 27mm deep socket or your existing one was aftermarket.

As mentioned in the other post on here, It is my own policy not to even touch the sensor wire unless it's 100% required when the intake manifold was removed.
It's not a cheap sensor and even just removing the sensor loom connector from this sensor could destroy it after being exposed to high temperature for a long time.
Quite often, you would even see melted sensor bracket in there.

The sensor size and the frequency spec are different from our NSX but ask S2000 owners about it.
You will understand the above as S2000 knock sensor is famous for failing without any warning lights and causing loss of power/torque.

The thread is 12mm but the mating cyl head side is aluminium so be careful with the torque.

I think the sensor is from 松下 (Panasonic) but it was such long time ago when I spoke with them so could be wrong.

It's designed to pick up specific frequency range using piezoelectric for the specific engine design so personally, I won't use aftermarket one or even the OEM from completely different engine model.


Kaz

[goldnsx]

You will understand the above as S2000 knock sensor is famous for failing without any warning lights and causing loss of power/torque.
I've never heard of any failure in an NSX so far and I hope it doesn't fail... Correct me if I'm wrong.

[wixer]

Thanks Kaz, I thought you'd have the answer. The new ones I've bought from Amayama, are exactly the same as the ones currently in the engine, as per my photo. I used a large adjustable spanner to undo the sensors but will get either a crows foot spanner or deep socket, as you say, to torque the new ones up.

Cheers.