Quote:
Originally Posted by ermax
Well actually the other three rod bearings looked really bad too. Bearings really shouldn't wear if there is oil pressure. The wear I had was clearly from oil issues. If it was something else like detonation you would see wear only on the load surface but all my bearings had wear across the whole surface. It was just a matter of time before any of them would have gone. The problem isn't unknown. It's oil starvation. The unknown is why is there oil starvation. I just don't think it's the packing. If you rule out people on 1qt of oil and the packing you're right back to asking yourself, what causes the oil starvation.
Don't feel bad about saying the sounds were normal though. After the rebuild it no longer had the knocky sound between 2800-3800 but after about 100 miles my knocky sound and exhaust leak were back. I've been fighting this stupid leak from day one. The way the knocky sound and leak sound came back at the same time has me thinking the knocky sound may simply be related to this leak. I've replaced all the gaskets multiple times. It goes away until it's heat cycled a few times and then the leak is back. I just need to take it to a shop that has the tools to sniff out the leak.
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My issue with arbitrarily dismissing the blockage theory is that it is a know factor. It does not have to directly block the affected bearing channel but anyplace within the system. Even a partial blockage anyplace in the system is going to change the routing of the oil. As we saw from the service manual specs these engines do run what
seems to be an abnormally low pressure at low RPM (whether that is bad or not is not up to us to decide since it is the manufacturer spec that they felt acceptable for this engine) so even a slight blockage anyplace up or downstream from the bearings could impede the flow to the point it staves them.
Another common point mentioned in the failures is when they seem to happen. Such comments as "I had just hit the highway from an on ramp" or I was accelerating from a stop" are very common in the failure threads. In fact the onramp comment was so common that at one point I was pretty convinced that the failures were the result of long(ish) curves pushing the oil to one side. Gave up on that one though since we see almost no failures on the track where that would be a bigger issue.
What I
think happens is that the sudden increase in pressure pushes the silicone into a channel someplace which in turn causes the system to stop moving the volume of oil needed even though the actual pressure may be fine. This of course does not help explain those circumstances where no debris is found in the channels.