I have an 81 300 TD 240,000. Last week I was driving back from denver and heard and ungodly clacking noise. I was convinced that it wasn't the new alternator I installed so I proceeded to dismantle the whole right side of my engine down to the block. After doing All this I realized my alternator ternsioner bracket was bent so I replaced this. The clacking sound went away. I do still have a very loud exhaust and power loss (no turbo). I noticed a metal fitting that mounts in the accordian coupling of the turbo I could not get this snug went tightening the turbo. exhaust seem to be coming from back of block, but hard to tell. Ohh yeah I replaced the manifold gasket after taking it off. I have not notioced any cracks in manifold. I loosened the exhaust manifold today and re tightened in hopes of losing the exhaust noise, no go. Any thoughts on over heating and loud exhaust. I have a good mechanic hear in the springs and I may have to go there on this one.