My parents encountered 2 major problems in their '91 Plymouth Voyager
3.3 V6 4-spd auto while driving it to take some big stuff to a store to return them for a refund:1)It was running fine at first but when they accelerated from a red light upon getting on a major road, the van stopped picking up speed as soon as it got into 3rd gear at 35 MPH. Basically, it bucked, hesitated. From then on, it lost speed even at wide throttle w/ pedal floored and then slowed to 0 MPH. And the engine cut off completely. He then put the shifter in "N" and tried to start it back up and he did. Then he popped it back in OD but it was sputtered and there wasn't much power. He went to a parking lot, parked it, and checked some stuff under the hood.
2)Now...the oil pressure. They told me that while they were driving it that day, the oil pressure gauge was reading 'nil'. The gauge was essentially showing no oil pressure. He mentioned something about the CHECK GAGES light being on as well.I drove the van a week before this scenario while my car was being fixed, and it appeared to run ok. It didn't seem to skip or anything. Oil pressure was ok; 1/4 at hot idle and a little below 1/2 when going down the road. I was told to check the fluids while I borrowed it, and I did. Oil was full, but it looked "dark" brown, or blackish. Based on the bottles in the van, the engine is presumably run on 10w-40 oil. Coolant, on the other hand, was wayyy down in the overflow tank. It looked like it had pure tap water in it, and it was way below the MIN mark. I opened the radiator cap, and I didn't see anything in the radiator. So, I topped the system off with 50/50 water::antifreeze ratio coolant. After I opened the hood and turned off the van to get gas, I heard gurgling sounds within the hoses/radiator. The van never ran hot during the time I drove it, though.
Anyway, the other day after the breakdown scenario, they got the van towed from the parking place where we parked it at, and it's now at a shop. They are looking at it. My dad said they might change the oil and put a scantool on it. They should know something by Mon.
Overall, what could be going on? What do you think should be done and what do you think could be causing the above problems?