MrJuls

I'm picking up phantom knock at around 5-6K Rpm.My tuner had the defcams on and said it wasn't real knock.

I know my car is almost due for a new timing belt,could it be that the pulley is causing this noise and the knock sensor is picking it up as knock?

Abacus

iTrader: (9)

The further you go from stock the more likely you will have to deal with phantom knock. Mivec,exhaust,cams,valvetrain all generate some degree of noise. Your tuner will have to spend some time adjusting the knock sensor tables, using det cans and logging knock sensor voltage. Its also a good idea to replace or check the knock sensor tightness.

Any voltage over 2Volts is considered knock IMO and should be treated as real. You can also add octane and check the phantom knock in that area. If it doesn't go away and there isn't any knock voltage then its not real.

There is also some good reading in merlins guide about it.
http://evoecu.logic.net/mirror/merli...UIDE-V1.7a.pdf

MrJuls

Thank you very much for the reply,I'm really worried about this...

Where is the knock sensor located? Maybe I can check the tightness and eliminate that for now.

boosted91t

iTrader: (65)

Back of block under intake manifold

MrJuls

Thanks for the help guys.

It's quite strange because this only started recently and I haven't changed anything.Today I checked all bolts and nuts for tightness including the downpipe and exhaust brackets.

todd6027

iTrader: (10)

so what did he do about the knock

MrJuls

Retarded timing and added fuel,but it's still the same.It doesn't happen at every pull,sometimes nothing,and then the next one....knock.

todd6027

iTrader: (10)

any logs ??

MrJuls

Yes he's got logs.But after this he said to go fetch the det cams because we tune on the road and that's when he didn't hear anything and said it was phantom knock.He basically just reinstated my old maps because he had to remove wastegate duty cycle due to overboost caused by a torn vacuum pipe.

So strictly speaking nothing was changed he just put my old maps back on and we did a few logs to make sure everything is still fine,and that's when we picked up this knock at 5000 rpm.

todd6027

iTrader: (10)

if we could see a log with afrs / timing/load etc we might be able assist but its like shooting in the dark without one

Raptord

iTrader: (10)

Logs don't matter as the knock's already been identified as not being real.

MrJuls

Exactly.

todd6027

iTrader: (10)

yeah right

todd6027

iTrader: (10)

have fun

Raptord

iTrader: (10)

Please explain to me how his logs are going to help you identify where his phantom knock is coming from?