I have a 95 Blazer w/ 141K miles...recently (Last Weekend-June 26th) changed out Water Pump, and Thermostat to cure overheating issue (Lots of Rust during drain and flush on coolant system)...at 130K I had Full blown Tune up done...Plugs, Wires, Cap & Rotor, Oil Change, Oil Filter, Fuel Filter, air filter and cpl other minor things...after 450 dollar tune up at a Mechanic, I noticed that my Oil Pressure was fluctuating alot between 20-60+, where before the tune up it was 40+ steadily.
10K miles later (I know too long for Oil Change but LIFE has other issues) Im driving to work, Engine is now at Normal Operating temp and I stop for a light and the CHECK GUAGES Light flashes and I see my Oil Pressure has dropped to ZERO...my heart dropped along with it...The pressure came back up to around 20...When my RPM's are up above Idle the pressure is steady 40+ but as soon as it idles it drops back to 20 or less...
I have no Oil Loss or Leaks. Could this simply be due to the fact I had the overheating problem that I was using the Oil to cool the engine with and now, after 10K without an oil change, and the Overheating problem, that my Oil is so Sludged now that it is cuasing the problem??
I am at work now and dreading the fact that I have a 30 Mile trip home.. with TX heat..and Houston Traffic...before I can attempt to change the oil and see if that helps. Any suggestions appriciated!!!