If bent rods were the result of ingesting intake manifold carbon/sludge then 603.96 and 602.96 engines would suffer from it as well (as they carbon up JUST like the 603.97 engines) and the rebuilt 603.97 engines would be doing it by now! That's not happening. The original OM603.97 engine design was the problem. With new rods, they seem to work just fine. OM603.97 engines almost never present with low power. High oil consuption/smoke or broken rods are the usual peresenting symptoms. Most low power conditions are because there is either insufficient boost activating the ALDA (and fuel enrichment) the ALDA aneroid is broken or the overboost circuit has been activated.

Marshall