TT Oil Pump Failure?

[VR4Play]

We've all wondered about low oil pressure readings at low RPMs. And we all replace the pumps at the 120K mile maintenance. But has anyone experienced a pump failure? And if so, what were the circumstances around the failure? Miles on car/engine? Warning signs? Miles pre or post replacement? Level of engine damage?

Thanks.

[cjbyron]

I had a guy bring his car to me for repair about a year or so ago. It was a 97 VR4 with 51K miles. It reportedly had zero oil pressure all of a sudden. The oil pump gears came out in about 20-30 pieces. Shattered. Was very ugly. Engine required an entire and in-depth rebuild.

Cause? No idea. Only thing I know for sure is it was low mileage when he bought it (51K) and he only had about ~<500 miles on it when it let go on him. No warning. He "said" he didn't drive it hard or redline it (reportedly a main cause of oil pump gear damage) and I believed him because it was his first car. We'll never know for sure what caused it.

Sad end to the story. After the whole rebuild and some other added work to the tune of almost $7,000, he was driving the car and a pickup in front of him dropped a bunch of fencing crap, 4x4's, etc. and he ran over it at about 50 mph. Car ended up being totaled by insurance company. This was only 2-300 miles after the repair.

Anyway, that's the worst oil pump story I have. Not a lot of technical data for you though.

[Trevor]

Split an oil pump gear in half at the track back when I was running the 3L. Stock gears don't seem to like life at 8300+ rpm. A fragment of the gear tore up the front main so I started leaking quite a bit of oil.

[donniekak]

Personally I believe the main issue with our oil pump gears to be how loose they fit on the crank.

An engine does not rotate smoothly. It jerks, due to the nature of being powered by a burst of torque that must be converted to rotational energy. This can be lessened with a heavy flywheel, and good torsional damper.

I firmly believe that a set of gears where the inner gear has a slight interference fit with the crank, would solve the broken gear issue. It is very easy to see where the gears, and crank are slamming into each other, in any used engine.