Hey guys,

I have a 2007 cx7 that started making a knocking noise. I suspected the timing chain, so I replaced it and the VVT actuator. When verifying timing by hand, the crank wouldn't want to turn past bdc. I checked the valves, and none were making contact. With a little more force the engine would turn fully, but encounters resistance consistently at BDC only. I removed the chain and turned it individually with the same results. I also removed the balance shaft, and checked one of my rod bearings. That bearing is fine, and the balance shaft made no change.

I also inspected the internals with an endoscope. I can't find evidence of anything making contact. Anyone had anything happen like this before? Or any clue where to look?

Thanks in advance. I'm out of ideas aside from main bearings, I really don't want to have to pull the engine.

 

So, It looks like the first cylinder's connecting rod is bent... About 5mm shorter than the rest of the cylinders at its TDC. The crank is twisted in such a way that it's interfering with the material on the crank. Wear marks on the conrod big end, plus the engine spinning freely without the connecting rod connected, support this. unfortunately I'm probably gonna need at least a conrod. Oh well. I'm glad to have found the problem.