Another thought occured to me after reading the RAVE manual on the bypass valve: is it possible that the leaking valve might be stuck, and if so... could that also be a cause of the oil pressure issue?

 

Could be stuck but the pressure is high enough to keep the light out after initial startup. The bypass is meant to "bypass" the filter when blocked.

The overall internal condition of the motor is more to blame than any one area unless the previous owner cleaned up sections and left others. I don't know if you can pinpoint the one item that is causing the low pressure at startup other than going through the motor and checking cleaning as you go.

 

Yeah, you're right. Focus on the big picture first and clean up the top end, then go from there...

 

Go ahead and check the bypass, I'm just as curious. Could give an indication, the Rave lists the spring length, check that.

 

Do ya think??? Here's the passenger side rocker at #4 and #6 cylinders (first and second photos, respectively). Am I correct to assume that the two larger holes below them are oil ports? And the two smaller holes at the bottom between the rocker arms--one of which is arrowed--ports or return ports as well? If so, they are packed to the brim with sludge. And I haven't even pulled the rocker assembly yet. So what kind of brewskis do you like?

 

Not so fast. Those are not for drainage, casting plugs and casting process leftovers. Drainage is up top, down through the push rod area....... I do see carbon though, on the valve springs and floor of the head. That is like sand paper to these engines before it makes it's way back through the filter. The rocker assembly must be removed from head and then disassembled to check rockers and shaft. Almost there........ It's takes several years to create the carbon. Mine looked much worse.

 

Right, okay. Just finished the rocker and there was definitely carbon in there. Shafts had a little bit of wear but arms and springs were good, pushrods were straight and in surprisingly good shape. Cleaned up the assembly and torqued it back on. Looks a heck of a lot better now. Also cleaned around the valve springs and inside the head. Quite a bit of carbon in there as well.

So passenger side is done. Unfortunately I got called into work early tonight and can't do the driver side til tomorrow... and I have to shuttle kids back and forth to school. Fingers crossed that driving for one day with one side clean and the other still dirty won't be too detrimental.

 

I don't think so, the filter will do it's job and then when you get time to finish other side do a fluid change........

 

Oil or coolant or both? Sorry for the dumb question. I've been out in the heat all day.

 

Heat stress....... oil.