Might try removing the starter. I have seen an incorrect starter installed (wasn't a Toy, but could happen there too) that totally locked the flywheel.

 

?? This didnt happen before?

Follow the lists made above and from there continue, i also agree witht he sludging problem as all toyota v6's had that problem when running regular oil.
It had to do with poor crankcase vent system.
I will upload some pictures of the difference between running synthetic and non-synthetic in these engines.

 

ok, sorry to hijack, i run castrol syntec blend, will that cause the sludging also? im at 143k now, and have been runnin that for 10k since i bought it. im assuming the guy that had it before me ran dino oil, as it had a kwick kar sticker on teh windshield, and when i changed it. i dont want any problems right now.

 

anything is better then regualr oil....

even preforming a engine flush will help

Its not a disaster but for some reason these v6's suffer from this problem vs any other toyota engine.

 

Actually Toyota also had sludge problems on 4 cylinders Camry as well (From 1997 to 2002).