Maybe a newbie question... Knock

[chef]

I now knock are supposed to hear detonation, but it hears like noisy lifters etc also.

I was wondering... I have a big boost leak and 43 knock.

So my dumb question is, can a boost leak cause a large amount of knock?
It the engine is not getting the air it is supposed to get?

Thanks!

Stian

 

[DSM90AWD]

So my dumb question is, can a boost leak cause a large amount of knock?
It the engine is not getting the air it is supposed to get?

Your ECU injects "Y" fuel for "X" air it reads at the MAS. If "X - boostleak" air is actually reaching the engine, the ECU still will inject "Y" fuel which would cause an over rich condition and your turbo to create excessive heat due to it's having to work harder to supply the preset boost level.

So in a nutshell.. YES.. a boost leak can cause knock (rich knock)

 

[chef]

Thank you for a good answer!

Stian

 

[flinguist]

If your knocking before turbo spool, you could be experiencing phantom knock. If you've got very noisy lifters that can cause phantom knock.