Mack EA7 Triton Head Valve Problem

[trevor19]

I have a Triton EA7-470 with engine problems.

Has anyone come across a snapped value steam that has caused engine failure?

Only has done 500,000 kms

Any input would be great.

Thank you

[Ezrider]

i am dealing with a snapped bridge guide right now, i personally have never heard of or seen a broken valve stem in my life, i have seen bent valve stems. typically caused by a loss of valve train control (to many rpms) and the valves float then causing a interference between the piston and valve, or the other common cause would be if the stem sticks in the guide typically a result of overheating.

i would imagine that if a stem actually broke the resulting damage to the piston. cyl and head even possibly the rod would be quite severe. 

[Mack Technician]

Most breaks i've seen have started with a broken valve spring that releases the keepers. I experienced it ......Slap slap slap slap bang. Once had a valve spring break, release the keepers, snap the head off stem, drive head sideways splitting piston and cracking head dumping entire cooling system into engine. 302 Ford.