First, I wasn't sure if this was the proper forum or perhaps maybe the Powertrain folder, so apologies on that first if I picked the wrong one.
After having read a few other archived posts with similar issues, there were a lot of theories but no sound solutions posted, so here goes.
I've got this 1990 Max with the 2.4L - all stock. I've rebuilt the upper end with a new head, exhaust manifold, rebuild throttle body and rebuilt ECU 9capcitors leaked). I got it running pretty good and then ran into major oil seal leaks on the front housing, so I pulled it and replaced all the seals including new bearings for the balance shafts. Maybe I should have eliminated them - but they're still there (for now) - and with new bearings. All new sensors including oil pressure switch (for idiot light), and I just replaced all the instrument cluster bulbs since they were so old and dim. now the oil pressure light is flickering on now and then and in some cases on solid.
No ticking, oil level is fine and opening the fill cap I confirm I have oil delivery to the top end.
I hooked up a gauge to the sending unit port and on cold startup I got 82psi. A bit high I thought. as the engine began to warm for the next few minutes, it dropped to maybe 78psi. FSM (factory service manual) states at idle and at operating temperature, it should be "11psi - or higher" a max level is not specified.
So I put the sending unit back on and same issue right away, flickering oil pressure light. One post had a theory that the high pressure blew the new sending unit. Another held a theory the oil pressure valve spring was worn.
If I blew the sending unit with the high pressure, I need to solve the cause of the high pressure before replacing again. Standard doesn't specify the range except to say the switch is activated at a low point of 7psi
How do you tell if the spring is bad? Are there other things to check/replace for a high pressure condition? I always thought 20-35psi was an ideal range, but I'm thinking 80 even at startup is much too high.
Thanks for the help!