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Thursday, December 15, 2016

DT466E No Start help, part 2


A very important thing to check before going any further is the engine oil level. If it was checked yesterday, check it again. If it was checked an hour ago and you are sure it is good and don’t think you need to check it, check it anyway. If there are no engine leaks and no oil on the ground, check it anyway. If the gauge shows oil pressure while cranking, check it anyway. Many times I have had to diagnose a no start and found the only problem was a low oil level. If there is oil on the tip of the stick there is probably enough to start but any time it is any lower than that, could be an issue.

The DT466E HEUI engine requires oil to fire the injectors.


     Remember that the HEUI system requires engine oil to fire the injectors. Especially in cold weather, a low oil level may not keep enough oil in the oil pan to supply the system. If the oil level is unexpectedly low and there are no leaks, there are two places it can go. The oil seal in the turbo may have failed. Take the boot off the turbo outlet and check for oil there. If that is where the oil is going and a significant amount has been lost, the air-to-air in front of the radiator will need to be taken off and drained. If there is lots of oil in the air-to-air and it gets to the engine the engine will burn it like fuel and cause the engine to over rev, causing serious damage. The turbo could also be leaking oil into the exhaust. You could take the exhaust pipe off the turbo but if lots of oil is being lost it should be seen at exhaust system joints and the exhaust pipe outlet.
      If there is no oil coming from the turbo, check the fuel in the tank. If it is black or dark grey in color and opaque, injector oil seals have probably failed and the injectors will need to be removed to replace them. (this last is for pre-2004 non EGR motors).
     This is a good place to caution against excessive use of ether to attempt to get an engine running. A small amount of ether doesn’t hurt anything, and sometimes is the best method to get an engine going without burning out the starter. However, if the high pressure pump is not getting oil from its reservoir, trying repeatedly to run the engine on ether will burn the high pressure pump up. Ether has little diagnostic value for a diesel engine anyway; any engine with adequate compression should run on ether.

Confirm that oil is getting to the high pressure pump reservoir.


     Oil in the high pressure reservoir can be confirmed by removing the oil temperature sensor next to the high pressure pump. A pint or so of oil should drain out of the sensor hole. If not, the engine oil pump is not delivering oil or there is a bad leak inside the front cover. Both of these problems are beyond the scope of this manual.
     If the above items check out, low fuel pressure should be suspected. Follow Diagnostic Routine 1: Fuel system check.
     If fuel pressure is to spec, follow Diagnostic Routine 2: ICP check, even if no active or previously active codes are set for that system.

     DT466E EGR engines start hard in cold weather.


     It is worth noting here that the EGR engines are notorious hard starters in cold weather. If not equipped with the optional intake grid heater, they will typically start very hard or not at all much below freezing, even with a block heater plugged in. A retrofit grid heater is available for engines not originally equipped with one, but they are kind of expensive. However, it is the only way the engine will reliably start in cold weather.

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