3116 and 3126 Truck Engines Failures Piston Contact
Multiple cylinders displayed outlines of the piston crown and the piston crater on the valve heads. This intermittent contact indicated a valve to a piston contact. This contact can be seen in the following picture. Look at the valve stems for the following items.
- Oil coking problem on sticky valves
- Adhesive wear
- Bent valve stem or stems
- ECM for logged conditions over speed
Illustration 7 g01183476
Piston contacts on valves