Toyota Repair: 92 Camry Sludge / Oil Pressure, downhill slope, oil sending unit


Question
I have a '92 Camry (4 Cyl).  Had an oil change, and was informed about a valve gasket leak.  Went back 3 days later for the actual repair.  The day before the scheduled repair, my oil light begins to flicker occasionally, and I figured it was low pressure due to the gasket.  

When I pick up the car, my technician shows me pictures of the sludge under the valve cover, and warns me that repairing could cause even more damage if not done right (which will cost me a fortune).  We discuss a couple of options; I leave.  50 yds out of the shop, the oil light comes on, steady.  I go back, we check a couple of things, and decide to replace the oil sending unit.  This time I make it about 3 miles before the light comes on.  It does not stay on constantly, and I can't figure out a definite pattern.

The oil light is not on at startup, but usually comes on within 30 - 45 seconds of acceleration.  The oil light also goes off when stopped on a downhill slope.

Is it possible I have significant sludge on the oil screen?  Or would you suppose it has something to do with the pump or a line clog?Something else?  

If sludge, would a flush alleviate the problem or make it worse?


Thanks in advance for your help,

Steve

Answer
I agree that there is probably sludge partially clogging the oil pickup screen, I would not spend any money trying to flush it but rather have the oil pan removed and the screen either cleaned or replaced, driving the car in this condition may cause serious engine damage.