Hi, new to the forum.I have searched, but have been unable to find a satisfactory answer. I have a 2002 chrysler Concorde LXi with the 3.5 L engine. It has always has a slight knock since I bought it with 60K miles on it 3 years ago. Anyway, the other day while driving home it started knocking loudly. I got home and drove it a few more times. The knocking was never very bad. Then it got to where it would shut off on me. When I rev the engine(lightly) and let off the throttle, it would die on me. But if I slowly let off it would continue running. The local shop says it is a lost cause. I can't belive this. And they want $4500 to replace the engine with a rebuild. RIGHT! My question is does anyone think it may have slipped timing ONE tooth on the belt, because I listened to the engine and the nose is coming primarily from the valve cover area. Thanks and any input is appreciated.

 

It sounds like you need a second opinion. I would have a compression test done to see if there is a valvetrain issue. I doubt the timing belt slipped if the engine performs normally. It may be a coincidence that it dies, or maybe the knocking is confusing the heck out of the spark knock sensors (no idea if this is possible)

Other than that if it needs an engine anyway, there's probably no harm in driving it until it blows up.