Lube oil accumulating in the cooling water system of a diesel engine will result in （）

A.pilot valve oil pressure
B.speeder spring force
C.compensation needle valve clearance
D.centrifugal force on the flyweights

A.fuel must be preheated
B.intake air should be preheated
C.lube oil outlet temperature should be increased 20℃ above normal
D.none of the above

A.carbon buildup in the exhaust manifold
B.overcooling of the exhaust manifold
C.eroded muffler baffle plates
D.high injection pressure