3.5L engine problems

[clcombat7]

I'm new to this forum and want some comments/input to my present Intrigue problem. I have a 2000 Intrigue with 91,000 miles on it. For quite some time I was fairly sure I heard a knock, especially on cold mornings before the engine warmed up. I had it in a local garage twice so they could have a listen. Both times it came back with "we can't hear anything abnormal". So finally I took it to the dealer and they did an oil sample. It turns out that the oil has a very high metal content, an indication that something is coming apart inside, and they hear the knock. Of course my confidence level with the local mechanics and their diagnosis skills is shot.
Then the dealer starts talking about putting in a new engine, at over $6000 with labor. The engine itself is about $4000. The dealer tells me that this 3.5L engine is not rebuildable. Evidently, GM/Olds designed it to be a 100% throw-away engine, and there are not even internal parts available! That info really shocked me. So I called a professional engine rebuilding shop in another town, and they called me back about an hour later and said they too could not find any parts for the 3.5L.
Does this sound familiar to anyone? If you have info about parts availability or rebuilt engines, please let me know.

[TLgunner]

From what I've read, unfortunately I think it's true about the "unrepairable" nature of this engine. It is a very complex design too which doesn't lend itself to repairs at the dealer (the FSM consists of two LARGE volumes, one of which is pretty much dedicated to the engine). Of course some of the accessories can be changed out but much of the engine internals are "non-user serviceable" and it's just more feasible to replace the engine if catastrophic failure has occurred or is iminent.

When you say the oil has "high metal content",. it sounds like a bearing(s) is gone. A new engine may be your only option.

I bought our Intrigue w/ the 3.5L engine because I saw a cut-away of the engine at a car show one year. I thought it was a marvel of engineering. Unfortunately, this engine was not cost effective for GM and so it was scrapped in favor of the newer "premium" engine designs. If GM had built it with variable valve timing, multi-stage intake and other high-tech/performance goodies along with more aggressive engine mapping that other entry level luxury cars were using at the time, this engine could easily make 275+ HP because of its "large" displacement. GM decided to eschew these premiums in order to make the engine more cost effective in the vehicles it was going to be used in. A wonderful engine not given the chance it deserved!