Dredging up old posts, because I'm getting some wierd noises, too.
But, reading through this drama, there's a couple of things I have to say.
First of all, I'm no expert, but I've been reading up on this problem a lot of late, and here are a couple of other tidbits.
According to "the master," there seems to be a problem with our sinter-forged rods stretching, esp on the 2.5s. He has found this by measuring engine parts of engines that have had bearing failure. I think, basically, what happens is the rod stretches, and (talk about tight tolerances) the piston starts striking the valve, or maybe carbon buildup on the valve. The impact leads to hammering of the rod bearing (causing the oil film to fail, etc.) which leads to bearing failure. Point being: it doesn't matter how much oil you use, or what kind of owner you are, etc. This is a case of a manufacturing process that seemed like a good idea at the time, but just isn't working too well out here in the real world.
Now, another thing that's pretty normal when the car is under load is pinging, which is caused by pre-detonation. Some of the things that Hodge Podge describes reminds me of a pinging discussion from another board. Still, pinging shouldn't occur normally at high rpm, but will occur often under severe load--high effort, low rpm (around 2500); IOW, while "chugging" the engine. Pinging could be made worse by carbon deposits, or other tuning issues.
See
here, and
here for more info on where I'm coming from with this.
