knock sensor location?

[eddyvr4]

is the knock sensor the plastic unit mounted on top of the rocker cover underneath the plastic engine cover? is it just the one, or is there also one on the rear rocker cover? (save me removing the inlet manifold to see...)

Thanks heaps

 

[bradc]

there is only one and it is in the middle of the engine in the block half way between the middle cylinders.

 

[eddyvr4]

im not sure if that confirms or denys what im guessing... is it this unit marked here? If not how is it accessed? (and what is the marked unit below then?) Thanks heaps.....

 

[Guest]

That's the ignition failure sensor. As Brad said the knock sensor is in the bottom of the vee and isn't very easy to see .

 

[eddyvr4]

Ok, thanks Peter/Brad....

 

[bradc]

Yep!

You have to remove the intake manifold, injectors and fuel rail to see it

 

[eddyvr4]

Ok. reason i ask is ive been trying to track down a buzzing sound under highish boost, (thought maybe knocking) and ive built myself a little DIY headphone amplifier kit with a piezoelectric detector which ive been clipping to various engine parts and listening whilst driving. Quite fascinating, clipping it to my boost ball bleed valve , or the factory BOV, and you can clearly hear the air whooshing through them on the headphones, it is incredibly sensitive. clipping it to the engine (to the ignition failure sensor pictueed above) to try to listen for knocking, i can hear the rustle of the engine, but no major change or buzzing when booting it hard on boost. (i would like to have clipped it to the knock sensor mount, but i doubt it will make any difference. still havent found the source of the noise yet. even clipped it to the wastegate actuators, and even the actuator rod, which i thought was the cause of the sound, but no luck there.

 

[eddyvr4]

wierd thing being ive clipped it to basically everthing to do with boost control, (wastegates, BOV, bleed valve, ) i cant localise it on the headphone detector, yet i can still clearly hear this buzzing coming from the engine bay even with the window up! (no radio). what else is ther in the boost control it could be? the factory EBC solenoid is unplugged. all the exhaust heatshields feel tight as. Its only buzzing at over 6-7psi in all gears. its a mechanical buzzing that sound like pinging

 

[bradc]

Try removing the boost controller temporarily?

It isn't part of the engine undertray and plastics?

 

[frozen]

hmm i get a sound under similar circumstances, and i had a workshop told me the sound was not mechanical... and nothing to worry about... its not really loud enough to record but definately there.. i think its normal - someone in one of my other threads suggested it might be the wastegates opening up letting more exhaust through, cause i mean it kinda happens around peak boost so yeah.. didnt expect that would make a sound without screamers though

 

[eddyvr4]

I have tested by disconnecting the wastegate lines completely, and the sound appeared to go away, but without wastegates i was only game to feather the throttle up to 1 bar, not punch it hard, as i didnt want to overboost etc. So it pointed very strongly to the wastegates, but the test wasnt 100% conclusive. I was hoping when i connected my 'knock tester" to the wastegates the sound would come through loud and clear, but i got virtually nothing, so im still in the dark.

Good suggestion Brad, the undertray and the rattly brackets that hold it have already removed.

Josh you are the second owner to report a similar sound. if it was a common thing and i knew what it was i wouldnt be so fussed, but its the lack of owners with similar symptoms that concerns me.. ive got to get to the bottom of it..

 

[frozen]

ive been told i do have a good ear for 'sounds' though - one member in particular cant even hear the turbos spooling so it may just be that you have a good ear for different noises? just a thought. i can make my noise go away by slightly lifting off the throttle, and it instantly returns when i put it on again. its mainly when im at max boost, making me think its just the wastegates combined with any mods including increased boost.. dont know for sure.. just speculations

 

[eddyvr4]

Yes, only under higher than factory boost and heavy load.. im same as you. maybe i start a 'poll' thread..

 

[pu-11-me]

As posted in the "other" thread -

I have it in the white car, but its VERY hard to notice..... Dunno what it is though. I don't get it on low boost, just on high. Sounds like its in the back of the exhaust on my car

Differences - Blue car is auto, and has a stock exhaust and the white car is manual with aftermarket exhaust. Chris (um318r) gets the same thing in his manual with aftermarket exhaust on 13PSI too