Hey guys and gals. So a little background information first, I have a 97 with the 4.2 in it. The other day we were driving home and my oil light came on and the gauge wasn't reading anything but it was still running alright. Well when I pulled in my driveway it was knocking a little bit and it died right there. So we replaced the oil pump and that didn't fix anything it is still knocking like it is not getting oil to the rest of the motor. My question is could it also be the oil pressure switch which is the sensor located above the oil pump like its not sending a signal to the ecu to open up or anything? Any input would be great thanks!

 

Not trying to sound impatient, just bumping to the top

 

Have a 97 4.6. Did the same thing as yours did with the light and gauge. Called my mechanic and he told me 99.9% of the time in those trucks it's not the oil PUMP it's the oil sending unit. He replaced that cost me $75 and works like a charm.

 

Thanks for that! The sending unit is only like ten bucks so ill get that taken care of today!

 

Well it wasn't the sending unit we replaced it and the oil pump this weekend and its knocking like it ain't getting oil to the top end of the motor... Any ideas as to what would cause that?

 

One of these will cause low oil pressure according to Ford:
Insufficient oil,Worn or damaged oil pump,Oil pump screen cover and tube,Excessive main bearing clearance,Excessive connecting rod bearing clearance. Of course if there is smoke coming from the exhaust, it could also be worn oil rings. All of those will cause low oil pressure.
My best guess is bad main bearings based on the knocking sound.
With that said, a good PROPER flushing ACCORDING TO DIRECTIONS of the oil system might solve the problem if something is plugged.
I hope it is something simple.

 

On the 4.2 there is a valve built into the timing cover that can stick and cause no oil pressure but it is built into the timing cover and has to be replaced as an assembly I would hook a manual oil pressure gauge and see if you have any oil pressure at all, if you have low oil pressure it could be main bearings or something else, also the oil goes through a tiny hole in the timing cover and can become clogged you may just have to start tearing into it

 

If you drove it even a short distance with 0 oil pressure there is a very good chance you wiped out a bearing on the crankshaft [rod or main] and no amount oil pressure is going to save it. How many miles on it? I hate to be the bearer of bad news but it is probably rebuild or swap time. Ihope im wrong good luck Bubbabud 2011 XLT SC Ecoboost

 

Bubba you are dead on the head. These 4.2 motors, once the OP drops to zip, usually are toast. When the light comes on, and any, I mean any unusual noise is heard, shut it down. The owner has most likely taken the rear main out (farthest from the pump), and is experiencing almost total OP loss. A new OP won't cure a set of washed out bearings, which it sounds like has happened here. I agree, I hate to bring bad news, but in this case, it's 99.9% terminal. Sorry, but you'd of been better off to err to the side of caution and shut the engine down or had it towed home. Good luck

 

Another victim of the Ford fake oil gauge (which is nothing more than a fancy light).
If it had been a real gauge, the guy would have noticed the oil pressure getting lower over time, and could probably have saved the engine.
Once again, Ford saves a few dollars at our expense.