engine stalls at idle when hot and also knocks at low idle before stall on 1998 Ford Escort

engine would not run,,, I replaced the fuel filter, repaired vacuum leaks, ran a little better.... but idle would go down and engine would start knocking and oil light would come on and stall. replaced IAC and car would run a lot better but still not idle (in drive w/ac on) at normal operating temp. car runs smooth above idle, but at normal operating temp. it will knock (below 1000 rpm and oil light comes on) and then stall.. 3 different mechanics looked at it with 3 different diagnosises..... HELP

Asked by for the 1998 Ford Escort
If you have an oil light coming on, first you need to do a manual oil pressure check to see if the oil pressure is ok.
Then retrieve any codes from the PCM and see what the sensors are doing. If there are any codes, repair those problems first and foremost.
Then test drive and re-inspect.
10-4 first thing I did was to check for codes,,,, none.
going to check oil pressure next