I recently bought a stock 07 6.7L with 80,000 miles. When I start it cold, I noticed the indicated voltage slowly rises to 14V, then slowly drops to 8V. About 5 seconds later, it comes back to 14V. It does this 5 times about every 20 seconds. Lights dim slightly each time voltage drops. Then it just stops fluctuating and runs perfect. If I blip the gas in the middle of this evolution, it stops fluctuating. Never comes off 14V when driving.
Is this a systems test or do I have a voltage regulator problem?

Another question- I can't hear my turbo. Is this normal?

This is my first computer controlled diesel. My other diesel is a Continental LDT465.

Thanks for any input. I have a 4400 mile trp coming up soon and I don't want any problems.

 

The voltage drop is just your intake grid heaters cycling. No need for concern. You'll find that at idle (during warmup) they'll continue to do this until the engine warms to a point. If you begin driving before the truck warms sufficiently to stop the cycle, the heaters will stop cycling when you've reached something like 20 mph.

As for the turbo noise, mine is quiet too. If you search the forum you'll see where some people remove the silencer ring from the turbo so that it makes more noise.

 

Thanks. Another problem solved!