93 civic ex.. I believe the engine is d16y6.

There's a little oil seepage around the vtec solenoid bolted to the head. Not too bad but i'm wondering if I pulled it off, replaced the gasket/filter thing, if that would help me with this knock that i'm experiencing. The car did not have the knock when I bought it and it has NOT been ran anywhere near short on oil since it's been in my care. Would the torque on the bolts that hold this on have any affect on how it flows oil? I am sure they're not loose,

And there'sthis knock happens anywhere from 1500 - 2500 RPM, under slight load. It is most noticeable when the engine is warmed up. A switch from 5w30 to 10w40 made a ever so slight reduction in noise but it's still there. (Or maybe it's just in my head).Engine has not been past computer governed redline.

 

you have the d16z6 and the "knock" you prolly hear is the valves cause they prolly need adjusting.

 

I have within the past 1000 miles adjusted the valves. The knock was there before and after I adjusted them. The clearance I did was .008 on the intake and .010 on the exhaust.Is there something else i'm missing?

Also, I notice that when I rev the engine, I can hear a noise like a "pum pum pum" when the engine is reving down near to idle. It sounds like the noise is comimg from under the valve cover but nothing looks obviously wrong. Could it be a cam bearing? How hard is it to replace cam bearings?

 

Also, can anyone tell me what the lost motion asssembly does? would it have anything to do with a knock? I noticed that when adjusting the valves, the second one over from the passenger side was a little less smooth and harder to push in than the others.

 

bump

 

In the general civic talk forum, there is a long stuck to top thread about how VTEC works.

The lost motion units are driven by oil that is controlled by the VTEC solenoid. They arethe next part involved in engaging the VTEC after the solenoid is activated.