Originally Posted by
89Vette
I don't know if this is posted in any of the links provided earlier in this thread. I got an answer on this problem/topic from Jerry, the Isuzu Guru. IIRC, he has been dealing with Isuzu Service and Training for 23yrs. And, he's been the recipient/trainer of Isuzu personnel at the Atlanta facility for a good portion of those years.
That said, his reply has to do with the ring construction. Because the original 3.2L engine was stroked to create the 3.5L motor used in the VX (and other Isuzus), it created a design problem. The wrist pin (which connects the rods to the pistons) was moved up very close to the bottom ring. 4 holes were drilling in the bottom (oil-scraper) ring for drain back. Depending on the driver's environment, oil-weight used, change-intervals, and PCV value operation, it can be easier to clog the holes on at least one of the cylinders. If that happens, oil does not drain back into the pan correctly which leads to oil starvation and engine failure.
I did not ask Jerry this but that makes me wonder if it's beneficial to run oil cleaner (carbon-tetra-chloride) thru the engine every 10-12k miles. Basically, this thins the oil and cleans deposits. You put in the crankcase and run it (at idle) for 5 mins before a change. The result should be a purging of any excess deposits/sludge in your motor.
OTOH, if you're like me, you don't go over 3k miles and drive off-road, you shouldn't have an issue. OTOH, if you don't know the history of the motor, cleaning it as described one paragraph up is somthing that can't hurt.
Seafoam is also something I've heard good things about that I'm considering trying. (OTOH, I've also heard (from good mechanics) that water injected into an intake will accomplish the same thing.) But, you should know that neither would do anything to clean the oiling-side of the motor. These types of products are designed to clean valves (aka topside).