why do diesel engines overspeed?

Question

what are the primary causes of overspeed

Answer 1

apart from external forces ie going down hill changing to too low gear, a diesel will overspeed because of the governor

Answer 2

Their are several reasons diesel engines overspeed. The turbocharger seal could start leaking supplying the intake with additional engine oil into the compression chamber. The driver had selected a gear ratio not low enough allowing the load to push the vehicle down a steep grade causing the brakes to fade resulting in the engine rpm's going too fast. The piston rings could be so worn out and if your engine breather is routed to the intake as they are on some engines the excess oil finds the way back to the compression cylinder and more oil then it needs and you will have an engine overspeed. Their are more reasons but these are the basics. Governor failures etc.

Answer 3

Depends on the year the diesel engine was made. Pre-computer-gov. going bad, getting air in fuel system. Old 2 cycle Detroit-"rack not set properly. Computer-sensor bad,sending wrong signal to fule pump.

Answer 4

Depends the Diesel engine...It depends how you drive and the make of the car..Truck whatever...OTher than that you need to be more specific

Answer 5

theres only 2 reasons:

1. some body is stepping on the exelerator

2. the car is driving down a steep hill.

Answer 6

they over speed because they are usually used on trucks and are driven for a long time. which causes them to overheat then the driver needs to slow own then needs to recatch up to speed in the amount of time he should be there i n by going faster

Answer 7

because of the high compression ratio,which gives very little clearance between valve and top of piston.The governor can get severeley damaged thru the engine over revving.