"plunge/tick" sound from engine?

[Tony_SS]

I don't know if this is of any concern, but ever since we got this van I've noticed a plunge/tick sound from the engine.... any idea's?

It runs and drives fine, but it sounds like something needs adjustment or?

[yeoldeoddy]

The valves need to be adjusted at 105K service, was it done?

Are you sure it's from the engine? Does it make the sound at idle with tranny in park?
If it does you can put a cut off broom stick to your ear and put the other end on the valve cover
or any other place (be carefull-not moving only!) that might be making that noise (like alternator PS pump, etc. It works like a poor man"s stethoscope.
If the noise goes on and off with the A/C controls, your problem is probably the a/c compressor or clutch.

[Tony_SS]

AC is off... it happens during idle and driving...

I dont think the valves have been adjusted.