Tag Archives for Failure

3116 and 3126 Truck Engines Failures Oil Quality

Varnished oil can accumulate on the valve stem near the bottom of the valve guides’ contact. This accumulation of varnish is similar to the happenings of valves at high temperature. The buildup of varnish can cause the valve to stick … Continue reading

29. July 2017 by samuel07042012
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3116 and 3126 Truck Engines Failures High Temperature

Valves for engines that operate in an overheated system will typically have a narrow band of oil coking near the bottom area of the valve guides’ travel. Mild adhesive and/or abrasive wear may be present. Valves in overheated systems may … Continue reading

29. July 2017 by samuel07042012
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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 … Continue reading

29. July 2017 by samuel07042012
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3116 and 3126 Truck Engines Failures Tight Lash

Valves may not display oil degradation, adhesive wear, or fretting if valve lash was too tight. Also if valve lash was too tight valve heads may show repeated contact with the piston. Tight lash may affect only one valve in … Continue reading

27. July 2017 by samuel07042012
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3116 and 3126 Truck Engines Failures Fretting

Fretting indicates repeated movement in a tight joint. Movement should not occur in the retaining area of the valve. Typically fretting is a result of the following items. Loose valve lash Engine over speed Sticking valves in guides Broken valve … Continue reading

27. July 2017 by samuel07042012
Categories: 3126 | Tags: , , , | Leave a comment