91 park ave 115,500 miles oil pressure issues

hey all,
i have a 91 buick park ave with 115,500 miles overall the car is running great....i recently had the magnet on the camshaft gear changed because it was disintigrated and the car was having starting problems...now my problem is that when the car is cold it shows an oil pressure of 40psi...after the car has been driven and is warm the needle is in the red (danger zone) showing like maybe 10 or so psi....sometimes when i have driven the car for a while and i go to park the car and turn the steering wheel all of the way to one side the car shuts off...i start it up and it starts...i do not know if these problems are related..i read in another thread that if the oil pump is going it would show good oil pressure when it is cold then when it heats up the oil pressure would drop...would this be my problem?...also the one thing i also noticed is the light on my dash that says "check oil level" DOES NOT come on when the oil pressure is really low...please any help is welcomed...thank you so much

Did the shop that changed your timing set also change the oil after they completed the job? If not, you may have coolant in the oil. When you pull the front of the motor off to access the timing set coolant flows into the oil pan since it is exposed and open. I hope this is not what happened, if it did you may be burning up your crank and bearings causing low oil pressure. see if your oil looks funky!!

i took my car elsewhere and they did a manual oil pressure test and they concluded that the crankshaft bearing or camshaft bearing is shot allowing oil to pass through causing oil pressure issues....yes they changed my oil and all of the gaskets..the mechanic put 20 weight oil in my car when he changed the oil they did not notice any coolant in the oil...they also put a oil treatment