Scanmaster not showing any knock but the knock gauge does?

[kirbdawg69]

Well I'm trouble shooting a popping under boost problem and noticed that the scanmaster is not showing any knock and the knock gauge does? Whats up with that? I know it should show something cause I had some popping this time when I took it out

 

["Turbo-T"]

Caspers gauges are known for showing knock when the Scanmaster isn't. I think it's a quirk within the gauges.

 

[bmackinnon]

Popping is not indicative of knock and won't show up on the SM as knock. Trust the SM over the gage....

 

[kirbdawg69]

yeah i know that popping is not knock but i have had it show up popping show up before on the scanmaster? It was weird? I know not to trust the gauge its always been screwy on the reading just thought it was strange that I didnt get anything on the scanmaster?

 

[WS6]

I think it's too quick to blame the knock gauge. For it's my understanding that the knock gauge "sees" the signal off the knock sensor rather directly, and the scanmaster sees the ECM's reaction to alledged knock.
So, both are right and neither should be ignored. I think it's more of how far upstream (if you will) either is getting information.

My TTA will register 1-2 green lights on the Casper's whenever I rollover this one bridge expansion joint here in town that I drive over allot. Yet the scanmaster will not register any KR to that incident.

So, the gauge is registering knock, maybe albeit the downpipe rattling and the ECM does not register the same incident...or ignores it.

 

[bmackinnon]

I think it's too quick to blame the knock gauge. For it's my understanding that the knock gauge "sees" the signal off the knock sensor rather directly, and the scanmaster sees the ECM's reaction to alledged knock.
So, both are right and neither should be ignored. I think it's more of how far upstream (if you will) either is getting information.

My TTA will register 1-2 green lights on the Casper's whenever I rollover this one bridge expansion joint here in town that I drive over allot. Yet the scanmaster will not register any KR to that incident.

So, the gauge is registering knock, maybe albeit the downpipe rattling and the ECM does not register the same incident...or ignores it.

not knocking the knock gage..... and agree 100%

 

[TurboBuRick]

Did you get the popping fixed?

 

[kirbdawg69]

Yeah plug wires and new plugs and a tt chip fix the popping runs alot better!