I have an 03 G Caravan and I have a terrible knock in the engine. The oil pressure dropped and it started very minor. I took it in to a mechanic Ive been dealing with for years and he said that a lifter had collapsed. He recommended a product called Marvel's Miracle Oil. I put that in along with an oil change and things were great for a week. The last few days though it sounds terrible. Is it possible that the oil pump has failed and is not circulating the oil in the engine? I can't afford a new car or a new engine in this one. Any help would be great!

 

Its possible the ol pump is going out. But you need to isolate the knocking sound, meaning is it lower end or top end of the engine. Could also be a cracked flex plate too. But that would not cause you to lose oil pressure. A cam shaft bearing could cause lost of oil pressure. Either way you may need to take the engine apart and inspect. But you need to isolate the sound first.

 

It is coming from the top of the engine passenger side.

 

Do you have 2.4L or 3.3L engine?

 

I have the 3.3L