possible serious oiling problem

hey all,

1990 4.0L has terrible oil leaks. the worst 3 places are the timing chain cover, the rear main seal and the distributor drive gear.

today i changed the oil and when i unscrewed the oil filter, no oil poured out of it. typically oil pours out of it and then when i remove the filter, there is still oil inside it. there was oil in the bottom of the filter adapter on the engine and there was some oil inside the filter, but i could see some shiny metal too, which lead me to believe that the filter had never been thoroughly filled with oil.

im not sure how the filtering of oil happens, but i have never seen this when changing a filter.

ideas?

-Tim

The oil system has a bypass valve, so that if the filter clogs up the engine will still get oil. The filter also has a rather primitive anti-drainback valve, so that it will not drain when you shut the engine off. I wouldn't worry too much if you had good oil pressure, because it's most likely that the anti-drainback valve in the filter was defective. That's especially true with cheap filters. Less likely is the possibility that the filter was clogged and bypassed, or the bypass stuck open. If you're really curious about how much filtering the filter did, get a hacksaw or something and cut it open. The insides will tell you.

It might be a good idea to hose down the engine a little and make sure that some of that leakage isn't coming from the O-rings in the oil filter adapter. Although I don't think it would become bad enough to starve the engine for oil*, it might contribute to draining down when it sits. Of the various leaks on a 4.0 engine, this is one that leaks under pressure, and it can get expensive.

* my 95 was gushing enough from the filter adapter to lose about a quart every 200 miles, and leave a trail as it pulled into a parking space, but the pressure never dropped.