| maximillian - 1/31/2026 10:39
Lance, your post reminded me of a question I have thought of before. With many, if not most newer engines have a common rail system, where fuel pressure in a common chamber as needed and injectors are fired electrically as needed. My question to anyone is what pumps that fuel pressure? A gear driven pump or oil driven pump?
We had a problem with a Cat C-5 this year getting fuel in oil from cracked injector and/or o-rings. We wondered about engine damage from such low viscosity 'oil.' The repair mechanic said that without oil pressure it wouldn't run so we shouldn't have any problem. So far we haven't seen any problem.
Does anyone have an idea? Thanks
Thinking t is a C-7.
But I searched for common rail systems and find gear driven pumps. So could the engine run without oil pressure or is there a sensor relief built in?
Your mechanic is correct. A C7 used a HEUI injection system. It used high pressure engine oil to make fuel injection pressure at the injectors themselves. The fuel rail in that case is simply a low pressure supply line. Very different from a HPCR injection system. |
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