Could a bad oil pump cause cold start knocking?

[JaimeG]

The truck makes a racket when started cold and not plugged in. I don't think it's the ficm since plugging it in "does" help (a lot). Oil pressure takes a about 5 seconds to show on the gauge. Also, my dipstick is broken right where it seals, so it doesn't seal properly, could that contribute to pressure loss?

[deucer]

Dipstick will not contribute to pressure loss. It will sprinkle your intake duct and coolant jug with oil and make you think your spitting coolant if it is split at the top. What kind of oil are you running viscosity wise, 5w-40? Has it been making this noise for some time or just since it is cold?

[JaimeG]

Running Rotella 5w40 synthetic and it only does this when its cold out.

[deucer]

I believe it is inherent of Diesel engine in a cold climate if you are not using the Block Heater. 5w-40 is a great oil for winter. I don't use the block heater here in Texas and on cold mornings mine will cackle for about the first 5 mins. or until the thermostat opens and begins distributing heat throughout the engine.

[JaimeG]

My original question still stands.

Could a bad oil pump cause cold start knocking?

It takes 5 seconds for the oil pressure to go up, compared to 2 seconds on my uncle's 05, which doesn't knock, and has never been plugged in to start.