2001 X5 4.4i engine Failure?!

[ryanm86]

I just bought this X5 3 months ago and it has been a living nightmare, I have taken it to 2 Reputable shops in Houston. One is telling me that its the timing chain and it will cost $4300.00 to repair. The other shop is saying that its not the timing chain and that they found metal shavings in the oil filter and on the dip stick. Their estimate is $5000+ to go in and repair. The car starts right up and drives but sounds like "valve clatter" mixed with "piston slap". Basically like shaking a box of rocks.

Any ideas? I am at the end of my rope with this car, I just spent $2,000 on a brand new a/c system for the car. I paid cash for the car so thankfully there is no car note

car has 122,000 miles