Just out of curiosity here, I have a question.

I know I am a noob, but I spend a on of time wounding engine oil on trails or pulling trailers and I also have rebuilt a ton of engines, both my own and for a friend's race shop.

Everyone talks about oil starvation killing engines, and assumes a blockage is causing it. This is fine, a dirty filter, degraded oil or massive sludge/coking will cause this, but this is usually not an issue with modern oils and engines; an idiot light or gauge more often than not tells you something is amiss. However, there is another issue that might not be as readily apparent.

What about over pumping oil?

We get a lot of guys who want engines rebuilt, usually larger American V8s for their high school Mustang/Camaro/Mid Life Crisis/Reliving their youth complex.

Almost all of them want higher flowing oil pumps and we recommend against them. They also want oil galleries increased and we say not to do it.

Fact is, most factory pumps and systems are more than capable of delivering well over the needed volume of oil and pressure to do the job, no matter what kind of power the engine makes. It takes a lot of work to keep an engine at 60 PSI when under load and the engineers knew it when designing these things.

We have seen engines maintain well over 120 PSI on the stand at speed when the blow off was blocked. And, more than once we saw pressure start to decrease as the sump dried out and the 6 quarts of oil in the upper engine could not drain back fast enough.

On the V8s, they end up with a quart of oil in the engine and 4 quarts in the valve covers.

The issue comes from push rod lubrication spraying instead of dribbling oil in the rocker areas because the pressure overwhelms the factory design specs for the volume of oil needed.

When that happens, the drain back is not fast enough to keep up. People think this is not really an issue, but it is, the oil simply does not fall right back to the pan, it takes a while to get there and when it pools, it can actually cover breather holes intended to help the oil not ævacuum lockÆ and drain back quicker.

Granted, a lot of OHC engines have a different oil system, but when I rebuilt my 3.5L in my Montero, there where actually small wear marks where oil was slung out during normal use and marked the insides of the cam covers. I saw places where I could open up openings and get more oil, but knew that starvation could be an issue. The Montero has a drizzle system that just dropped oil in the journals and the lobes slung it around inside the covers to lube the rest of the valvetrain.

As odd as it sounds, over oiling can lead to sludging as well. A lot of components (like turbo bearings) rely on proper oil flow to cool them as well as for lubrication. If oil is pooling, it might lubricate, but it is also over heating. Every time that happens, a little gets coked and stay there as crud that can restrict passages.

Just an idea. People always think more oil is better, but sometimes it can really hurt a situation.