In most cases its a down pipe banging or something loose

We have not seen that many can journals on backwards - BUT I have seen a few on LOOSE

 

This is a very true/factual problem with tuning and such.

I had a car come here last week for some very minor work. The car was completely built from top to bottom. Not a single part on it from our shop. We added wiring from the alky kit to the AEM, that's it.

Started tuning the car on the dyno. Got very very scared from the rediculously high knock counts. Studied the map that was in the car, double checked the wideband in the car and on the dyno. The car continued to knock. We verified the timing, found it was off a little, car continued to knock.

I even took some extreme measures in my tuning to ensure the car could not possibly have knock counts as high as it did. I actually retarded the timing to -1 and still had the knock control pulling an additional -15 degrees more. So at that point it was obvious that there was no way it was detonation.

I called the customer, got his permission to turn the knock control off and tuned the car. With a very conservative tune the car made 395 whp on our dyno. I let him know to look the car over and try to find some things that could cause it.

This morning he called to let us know he found one of his engine mount bolts completely missing from the car.

 

I have noticed that after doing a clutch people really need to check their motor mount bolts. I got my clutch done at a local shop and when i looked over everything in my garage i noticed that the front and rear motor mount bolts were very loose. Luckily i caught it before they fell out. For now i am going to take my valvecover off and check everything out like Al suggested and see what happens.

 

If the end journal was loose enough for to bang around in there then I would guess the other journals (caps and head) are gone. I would ask for a new head - no pun

 

Good Catch Al and this thread was a Good Read.

Being the investigative person I am, I'm curious on the dynamics of the knock sensor. In short, the knock sensor is a microphone. It converts mechanical motion into an electrical waveform. The elements that do the conversion have a spectral (frequency) characteristic.

Does anybody know of, or have seen any diagrams that would show the characteristic of the EVO 4g63 knock sensor?

Cheers,

~j.

 

^^ Yes!!

 

Thats really good to know too, i recently had my clutch done at a local shop, just a few more things for me to check out