possible oil pressure problem

So i got back from a trip about 180mi on the highway. I noticed when i was on the highway that the oil pressure needle was buried, and when i got to town and stoped at a sign or light that it droped down and when i accelerate the needle gets buried past 80 and the trans shifts to second and drops down, and when i accelerate more it gets buried.
1. i have an oil leak around the drain plug for somereason (got the oil changed at a shop (i was lazy to do it myself)
2. its leaking coolant from this funky thing were 3-4 lines are connected to it near the firewall next to the motor

anyone have any ideas or experiance with this?
i have a 91, 4.0 motor auto trans and i have 150k on the motor

Thanks!

It's likely that your oil pressure sender is bad or just has bad connections. If you can put it on a true guage to check the pressure, do so. If not, check your connection and/or replace the sender (it's' the thing right next to your oil filter with a wire on it). I think they run about $12-15 at AutoZone. 2 minutes to change.

1. The oil leak may be either from a leaky or missing washer/gasket thing or you have a leak either from your rear main seal OR oil filter adapter o-ring OR your valve cover gasket. It's a good idea to clean everything up so you can actually see where the leak is coming from. All of the above will get onto your oil pan and the drain plug area being the lowest point, that's where it drips from.

2. The funky thing is your heater control valve, they do fail and leak. Unfortunately they dont make a metal one and the diaphragm isn't fixable so you have to replace it ($22.00 at AutoZone or $28 at NAPA). Same part. 10 minute job.

Hey thanks alot for the help!

I'm having the same high-pressure problem. running 50 at idle, and 80 at speed. no leaks for me, though. that's what I get for doing a burnout leaving my job for the last time.

i fixed the heater control valve no more leaking coolent that was super easy now i just have to do the oil pressure sender

that's almost exactly what the '96 i just bought was doing, it was the pressure sender.