Messing with Knock sensors

**Drifty Midship** · 22-09-2008, 02:23 PM

I'm building up a 7 rib 4AGE to a late ZE spec. but of course have come up against a problem.
Basically the ADM block does not have a hole in it to put the knock sensor... usual position is just under the intake between cyls 3-4.
Now I've un-screwed the Knock sensor out of the old ZE block and the thread is M12... Where as all the spare holes in my ADM block are only M10.
I know little of the actual dynamics of the Knock sensor so have several questions.

1. Is the position of the knock sensor in it's original location critical to it's correct operation? eg. if i moved it to one of the other existing spare holes in the block will it still work as it's supposed to.

OK if the answer to the above is NO then I can relocate my existing sensor.... but to make it fit I have several options....

1. Since the existing holes are M10 and the sensor is M12 thread will it mess up the operation of the sensor if I machined it down to a M10 thread so I can fit it in an existing hole... same intake side just lower to the sump and between cyls 2-3.

2. or can I get a little adapter machined up that has a male M10 thread and a female M12 hole and use that... will it mess the knock frequencies by sitting on an adaptor to the engine...

My other option is drill and tap the block but i can't do this myself and since the engine is now 90% assembled it's not real a) accessible and b) transportable.

I'll be using the factory ECU from SC AW11 but with 8.9 c/r pistons up from the 8.0 c/r... so I think Knock sensor is a little bit important.?!?>!

Any advice or suggestions appreciated.

Cheers

**TooF** · 22-09-2008, 05:34 PM

http://www.atsracing.net/ats_racing_knock_sensor.htm

as per our conversation the other day this is the sort of unit id be looking at

**Drifty Midship** · 22-09-2008, 05:52 PM

That replaces in the stock location... so no good for me...
But answers my adapter question.
I'm just gonna run my existing sensor thru a die down to M10 then.

**TERRA Operative** · 22-09-2008, 06:12 PM

You can place the knock sensor anywhere on the block tht's near the cylinders.

**TooF** · 22-09-2008, 06:41 PM

oh yeah i reaslie it isnt suitable for your current situation but it answers the adaptor question. as long as its in good solid contact with the block you should be sweet

**JustCallMeOrlando** · 23-09-2008, 11:15 AM

Excuse my ignorance, but since when does knock....killl....a knock sensor?

**Joshstix** · 23-09-2008, 11:48 AM

Originally Posted by JustCallMeOrlando

Excuse my ignorance, but since when does knock....killl....a knock sensor?

All the time. This is one of hte most common things to make a 3S throw check engine lights and run like a sack of crap.

They are fairly delicate things really.

**CrUZida** · 23-09-2008, 06:03 PM

Random.
Every time I've heard of a knock sensor code its been due to the wiring breaking down.

**Joshstix** · 23-09-2008, 06:26 PM

Take a look around on one of the MR2 forums for knock sensor failure, it's very common.

**SuperDave** · 23-09-2008, 07:38 PM

This is a coincidental read. I believe I have a dead knock sensor on my 2zz, are there any checks that can be done to the knock sensor?

But to help the original poster, is there not an issue with retapping the hole to M12? I've no 4A experience so not sure if that is possible.