Hi,

  I have the valve cover off a 96 Nissan Sentra DOHC 1.6 Liter engine,

checking for sludge. It looks very clean except for some round cups
that face upward ( 10 of them)  and are about 1/4 inch deep, about a
half inch in diameter, and are raised above the surface of the head.
These cups have gritty sludge
stored in them. All the other surfaces, that allow the oil to flow over

them are clean. The "buckets" are all full of clean oil.

 I cannot locate the oil returns. I poured some oil into the head and
tried to see where it went, but it just sort of oozed away and
disappeared.

Where are the oil return holes ???

 ANother question :    I was able to move the timing chain in about a
1/8  inch or so by pushing down on it with my finger. Is that too loose

?

Thanks !!