Oil Pump Failure
About 3 months after rebuilding my timing case, somethign bad happened. I was getting onto an expressway near my house, and decided to redline the car in second gear. As I shifted into third gear I noticed that the engine was suddenly very sluggish, and the instrument cluster's oil light turned on. The engine promptly died. I pulled over, wondering what could have possibly gone wrong; there were no loud noises of any sort, no crunching or smashing noises. I decided to try to start it. It fired up, and the valve train was VERY loud. I turned it off after a few seconds.
Once the car had been towed back home, it was time to inspect things. By this time I had narrowed the failure mode down to the oil pump or the oil pressure check valve. I sincerely hoped that the spring in the pressure check valve had gone south. So, as anyone who has had their car hiccup mechanically does, I jacked it up to pull the lower oil pan off with the all-too-familiar knot in my stomach; the "Man, I hope this is not something major" knot. I cannot say that I was eager to pull the oil pan.
So, after crossing my fingers I took it off. Looking at the stuff that was hanging out in there, I knew that my oil pump had probably been hanging out with the wrong crowd. A little further inspection up into the bottom of the timing case did not show anything terribly promising either. To the best of my knowledge, big pieces of broken cast aluminum are not supposed to be in there.
This was definitely not a broken pressure check spring that I was dealing with here. Upon removing the oil pump sump I started to put some of the pieces together about what happened (no pun intended). Having a piece of metal fall out of the filtered side of the sump screen/sump was not good; definitely a sign that somrthign in the pump had broken. Looking closely at the screen, I realized what had probably happened. There were many small pieces of hardened bearing shell in the pan. They were from the car's original timing chain that I had replaced shortly after purchasing the car. I had not realized how much material had come off of the chain, and had not bothered to check the oil pan for debris. There was a screen on the oil inlet anyway, right?! Well, let this be a lesson to you: after rebuilding the timing case, check the oil pan for junk!
So, what was the extent of the damage? The timing case was done-for, as were the oil pump gears. Positive displacement pumps, especially ones driven directly off of the crank shaft, will stop for NOTHING. Being that the gears mesh with nearly zero clearance, it does not take a very sizeable piece of debris to shoot the whole apparatus to hell.
I will have a writeup on how to rebuild a failed oil pump in the articles section when time permits. Let's just say that the process is not for the faint of heart.