The noise I thought was secondary chain slap, may be something else. After replacing Secondary Tensioners, the noise continues.

At startup, if the engine is given aslight bump in throttle, there is a noticible noise. It is a littlemoresolid than a click, and it seems like something is moving back and forth. Like a knock on one side, then back to the other.

Originally I thought it might bea lifter tap, but it is not dependent upon engine speed.It isnot a regular tap... tap... tap... It can repeat itself, but the phase is random. It seems to be a back and forth noise

Using my trusty engine mechanics stethescope, this click/clack seems to be part of either the VVT selenoid, or VVT unit on the camshaft ends. It isnoticible on both A Bank and B Bank VVT units.

I searched "VVT"and saw references to ECM signals, oil pressure, timing retard, etc. Is there a common diagnosis for this?

BTW my engine was Sludge City when I started my Tensioner Project. However, this knock has been going on well before any de-sludging began. Could sludge have plugged an oil galley on this device; or am I hearing the selenoid click on and off? gordo

 

that is a common and normal noise.. to an extent.. from reading your post .. sounds normal..