X15 Rear Bank Injector Short Circuit

[Hermjeji]

On the X15 we have, following FC's came up: Fault Codes 323, 325, 332.

Engine is still under warranty, was close to a Kenworth dealer and they're looking into it. My hunch is something to do with the harness if all 3 came up at once. The wiring diagram shows the injectors going to the ECM directly, would there be a difference with reference to the rear bank vs front bank? Looking at QSOL, i don't see where the rear bank of injectors would be combined vs the front bank.

Anything I should look out for, I'm well aware of the fears of having this done at a St**lerSH*t.

Symptoms were derate code came up and engine started running really rough. Drove it about 5 minutes from when it came up from when I dropped it at the dealer.

[marek4792]

My money it is a bad Exhaust pressure sensor. I replaced mine doing an egr tuneup with aftermarket got a check engine fault rear injectors. Put old oem sensor no more check engine light.

[Hermjeji]

Well, here we go again folks. Never a dull moment....
Time to add some details:

340,000 kms
10,000 hours

Hauling heavy at 61,000 kgs. Injector code came up as discussed when empty, took it to the place of evil due to warranty:

1. Cam lobe #4 is flaking and the associated rocker arm is damaged. They are replacing the cam and the rocker arm for sure.
2. They are checking the filter for metal and the oil cooler, potential progressive damage.
3. Still haven't found the cause of injectors.

I've read a lot on the cam wear mystery (non-mystery), and I've only had this truck for several months. At this point, i'm looking to see what else I should be looking at.

Do I go out of pocket and replace the assembly, or is the one fine If the others check out within spec?
With only one cam lobe flaking (that they could see so far) what do I guide them to look into.

Here's the cam lobe and rocker roller at cylinder 4:

[tree98]

Was the overhead ever set since it was new?

How often do you change the oil ?

By the way...... your fuel pump is due for rebuild.

[Rawze]

(11-11-2021 )Hermjeji Wrote:  ...
I've read a lot on the cam wear mystery (non-mystery), and I've only had this truck for several months. At this point, i'm looking to see what else I should be looking at.

Do I go out of pocket and replace the assembly, or is the one fine If the others check out within spec?
With only one cam lobe flaking (that they could see so far) what do I guide them to look into.
...

=============

Ensure it does not fail again ....

* Ensure there is no way that crank case fumes can build pressure in the engine. Not replacing the crank case filter often enough causes premature cam failure because higher than normal CC pressures it starves the top end of oil. Many people switch over and use a maintenence free CC filter and this helps prevent this. Here is a maint. free one: http://rawze.com/forums/showthread.php?t...50#pid8950

* Ensure the overhead valves are adjusted every 250k miles.

* The ISX does not like extended oil changes and a lot of failed cams have happened when people use those bypass systems and extend their oil changes.

* Based your oil changes on fuel mileage (or equivalent engine hours). -- (At the bottom of post in this link - http://rawze.com/forums/showthread.php?t...617#pid617 ). The general rule of thumb for oil changes on the ISX is ...

Rawze Wrote:If your average fuel mileage every 10,000 miles is ...

less than 5 MG -- Change your oil every 8,000 miles or so.

5 - 6 MPG -- Change your oil every 10,000 - 12,000 miles or so.

6 - 7 MPG -- Change your oil every 12,000 - 15,000 miles or so.

7 - 8 MPG -- Change your oil every 15,000 - 18,000 miles or so.

8 - 9 MPG -- Change your oil every 18,000 - 22,000 miles or so.

above 9 MPG -- Change your oil every 22,000 - 28,000 miles or so.

Last but not least, if your fuel pump has more than 400k miles of run time on it, then it needs its guts replaced to prevent total engine destruction without any warning.

[tree98]

Can't speak for all X15's but mine doesn't have a crankcase filter, never did.

Came from the factory with a small box plumbed into the breather hose bolted to the side of the engine where the crankcase filter would be on an ISX.

I took it off and inspected it....... it's hollow, nothing inside.

[Hermjeji]

So, new cam, new rocker shaft, new jake brake rocker assembly, new injector, injector cup fix, and now the exact same codes came up:

332, 323, 325.

EGR tune up was done just a few months ago, and the overhead set.

I'm thinking it's pointing towards the injector harness. Both times it has been the rear bank only.

[marek4792]

Did it start after the EGR tuneup because if so. You definitely got a bad Exhaust Pressure Sensor like I mentioned earlier otherwise you're throwing parts and money at hoping it sticks when in fact it is a sensor gone bad!!!!

[tree98]

332, 323, 325

What are those codes?............ for us that don't feel like looking them up.