Dmax troubles

[bigtruck42]

Hello everyone!

I am having some issues with my LB7. Let's start off with the basics, it currently has 258,000 miles and it is a 2003 CCSB.

I have been experiencing loss of power and fuel mileage, down to 14-15 mpg and that is calculated at fill up, and have developed heavy black smoke at full throttle.

I also have:

* Fuel in the oil
* Heavy blow by that comes out of the oil filler cap (when taken off) and dip stick tube
* hard upper radiator hose

I purchased the truck from a SC dealer and which the truck was dealer maintained its entire life (have full service records)

The injectors were replaced under warranty/recall at around 150,000. But I had the balance rates done, which 2 are getting close to needing replaced.

Here are my thoughts to what is going on, but I am new the Dmax world but a Navy trained construction mechanic. So I know and understand motors just don't the brand that well yet to effectively diagnose the problems.

* may have an inject cup backing out or already has backed out
* bad head gasket
* cracked piston
* bad rings
* minor boost leak (black smoke at full throttle)

Will be doing a compression test and pressure test on the intake this weekend but if anyone can help, PLEASE DO!!!!!!

thanks!


bigtruck42!

 

[Brent@LDS]

Sounds like it's time for injectors.

 

[catman3126]

Might want to run a comp test before throw several thousand at it for injectors and make sure the cylinders are healthy first. Also heavy black smoke could be an indication of a weak CP3 and not maintaining rail pressure. poorly atomized fuel is the result of a weak CP3 and at that many miles I wouln't doubt it.