Wow, sounds like $2000+ job. Labor charge at least $1500. So if you DIY, you have to lift the engine out and open it up? Guess I have to go to a shop for this kind of job.
By the way, is there a easy way to find out whether it's the guard rails or not? If I drain the oil and take off the oil pan, should there be some guard rail debris in there?
The noise is more like a high pitch "hiss".