when the car is warming up, the gauge reads right in the center which is good but once it warms up it drops very low at idle but raises when i hit the gas. i used the lucas additive and did nothing is this a problem?

 

First.... need to know what specific engine you are asking about - why not add a "Signature" with basic info about your car - year, model, engine, trans and any major mods.

What are the exact numerical readings at what specific RPM? Not all gauges are calibrated the same - e.g. V6 vs. V8's in the 4th Gens. "in the center" and "very low" are vague terms. The engine typically idles higher when its cold, so there's more pressure because the oil is thicker and more pressure because the engine is turning faster.

What viscosity oil are you using? How high does the coolant temp get "when it warms up"?

 

I just had this issue! on my 97RS 3.8V6 Its your Crankshaft Bearings...You can replace them but its going to require a COMPLETE motor rebuild as it is in the bottom of you motor. Per my Mechanic {Shade Tree & Firestone} They say a good used motor will be cheaper. I got mind for about 2k