View Full Version : Knock Sensors?
I'm looking to fit a knock sensor on my motor, to monitor my engine from going boom and so I can use all of the features on my safc2. I was planning on getting hold of a Vauxhall / GM (bosch?) knock sensor (as I can get them dirt cheap and new)
Will this be ok to use or not? My mate seems to think they are engine specific? Or is this a load of crap?
welly_59
11-01-2006, 02:30
dont think they are engine specific, but not sure!
Driftin_AW
11-01-2006, 05:21
I've heard they're engine specific. I'm suprised it doesn't already have one though
Paul Woods
11-01-2006, 07:33
like malcolm says,arent they already equipped?
I don't believe so... I couldn't find it anywhere and I did ask on imoc about it.... if anyone hapens to have a 3SFE engine manual they could let me know... I haven't seen it on wiring diagrams or in the parts catalog.... Also where I thought it should be on my ecu wiring loom is just a blank plug #-o
All of this makes me think I don't have one.... If I do where would it be? I found something that looks like it in the head but aparently thats an oil pressure sender :?
Driftin_AW
11-01-2006, 11:02
the knock sensor will be on the back of the block, under the intake manifold. Although it's not installed in this picture, the knock sensor normally resides in the threaded boss above the frost plug in the #3 cylinder (2nd from left in this pic)
http://www.twobrutal.co.uk/forum/images/recovered/2006/01/19.jpg
Cheers for that... No sign of it that I can see... i've had a brief look.... The question is will a GM knock sensor do the job or not?
Paul Woods
11-01-2006, 17:42
all depends whats compatable with the safc2? i reckon you should be ok with any of them,cant imagine apexi making it sensor specific? i could be wrong though.
superchargedsam
19-04-2006, 16:21
Goldy did you ever do this as I need a new knock sensor for my celica and dread to think what MRT will charge and Dan has informed me he "thinks" it might be possible to fit the GM once so wondered what price you could get them for as really want the celica running smooth again for weekend fun when the SC gets retired next month !
superchargedsam
19-04-2006, 16:23
Failing that does anyone have a spare knock sensor I can try before buying a new one as Dan says its possible the cable become brittle and breaks down so might just need a new cable running to the ECU ! Its a pain as the charge cooler pump seems to have failed as well so got a few bits to sort on it along with those stupid tyres !
I've got a gm one to pick up this week when I get round to it.... I think they are ?40 from vauxhall. There are two types. The one i've seen looks like a doughnut and you put a bolt through it to connect it to the block. Its a 2 wire jobbie. Aparantly you earth one wire and the other one is the signal.
Let me know how big the thread is on the toyota one, and i'll find out if it'll fit.
Moving this to mk2 forum
Got the knock sensor in my hands ;)
Not tried to wire it up or attach it to the block yet... Its a bosch 2 wire knock sensor.. code : 0261 231 006
heres a piccy for you sam.... see what i mean bout doughnut shaped :
http://img435.imageshack.us/img435/5979/dsc005152ld.jpg
The centre hole is about 9mm accross so should fit an m8 nut.
Any measurments on the standard toyota sensor thread?
Sponge Bob
21-04-2006, 01:10
DOH!! I just read today a 4 page long thread on MR2OC about knock sensors - apparantly the GM ones are not good at all - I will find the link and post it here, but some guys did proper tests on the sensors and posted all the graphs and data and then fully explained how the stock knock sensor worked well and that the GM one didn't fulfil its function properly... will find link tomoz when look at work internet history mate - it was a very good read actually.
Sponge Bob
21-04-2006, 12:11
http://www.mr2oc.com/showthread.php?s=&threadid=48419&highlight=knock+sensor
here's the thread - it's def worth reading through even though it's pretty long
Erm cant get on there as i'm not a member... any chance of a local copy?
I think most use the chevrolet gm sensor as sold by twosrus, it looks completely different to the one ive got, I'm not even sure if its made by bosch?
Chevrolet GM sensor : as sold by tbdevelopments / twosrus
http://www.tbdevelopments.com/catalog/images/knocksensor.JPG
Sponge Bob
21-04-2006, 14:43
Be easier to join up - takes 2 mins - it's 4 pages so I don't think Nik would be impressed if I copied and pasted it here :)
It's irrelevant now as you have one, but still worth reading mate!
welly_59
21-04-2006, 15:02
join up goldy, mr2oc.com is a good site anyway!
Right, signed up..... read what I count to be quite a lot of panic mixed in with people who know stuff and people who dont.
The long and the short of it are.... that the gm sensor (chevrolet one) pictured above and being discussed on the OC is tuned a different frequency than the toyota one, due to the different cylinder bores / block materials. (100mm bore vs 86mm bore on a 3sgte)
The good news is, the sensor i've got is from a C20-LET vauxhall engine, which is 2litre turbo... and has ...... 86 mm bore, so in theory it should be a direct swap, though I havent tested it.
Has anyone got a spare toyota knock sensor going? I'll do some independant tests vs the one i've got here.:whistle:
superchargedsam
21-04-2006, 15:44
goldy if i try taking mine out and send up to you can you test if it works then as it could just be the wiring thats fubbared !
I can try... Though i'd try testing the wiring with a multimeter 1st, Put one end on the ecu pin, and the other on the sensor connector, to see if you have a connection there as a simple check.:shrug:
Pulled a classic one today : Tried to fit this sensor. The standard knock sensor hole is 12mm (I think) and the gm one is 8 mm.... bit of a problem there. Was looking on the block when I spot a bolt below the knock sensor mount.... I know i'll just put it on there...... Undo the bolt after 20mins of wrenching shoulders under the car and cutting my knuckles, got it off.
Coolant all over the show.... Oops... Be advised don't undo that bolt unless u want to drain the coolant!! :doh:
I need to find somewhere to bolt it into, else get one of them adaptor thingys made up... or an 8mm hole somewhere on the block???!
Paul Woods
26-04-2006, 06:48
mental image of goldy still under his car with his finger in the hole lol
Yea it was a bit like that... I couldn't get the damn bolt back in after i'd taken it out :(
Anyways you don't want to waste precious coolant... it costs more than beer ;)
Knock sensor now fitted.... I've ended up bolting it to the lower part of the head, about 1mm above the block, as there wern't any other options really. I figure it should still be reasonably inline with the combusion chamber.
It seems to work with the safc, I'll be road testing it when i'm sober ;)
Anyone got any sample knock readings? from an safc or powerfc?
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions Inc. All rights reserved.