Paccar MX 500

All 48 dear sir.. still waiting on the bridge to Hawaii.

This gentleman here knows the ins and outs of the new engines, perhaps.

Not long haul.

Either Cummins or Mx are both where it's at.

 

I've picked up a gripe with the PACCAR engines, and perhaps @Thed302 or any other Kenworth/Peterbilt/DAF techs can offer some insight here.
So the dosing injector was moved to a location similar to the Cummins, but instead of being mounted to an exhaust elbow, it's mounted to the back pressure valve.
So here's the problem: the bolts for the dosing injector keep seizing and snapping inside the housing when you try to service the dosing injector - and this is happening at the first dosing injector service. My company (which I'm now a part-timer at) sets the service interval at 120,000, with a 10% advance tolerance (so, 108 - 120k).
We've never been able to successfully extract one, and you can't drill them through, so we end up having to replace the BPV. No problem, warranty covers it, right? WRONG. MHC tells us that since one of our techs broke the bolts, we eat it. Oh, by the way, we need to update the coolant lines, too, since the old push-pull ones are proving a bit flawed. AFAIK, no campaigns or TSBs exist regarding this issue. It's happened to at least eight of our trucks, and mechanics I know at other companies running that engine have reported the same issue. So, is PACCAR working to sort this out? Have they sorted it out and just somehow not gotten MHC up to speed? Or are they just letting it ride until the inevitable class action comes about?
I was reminded about this Monday from having to replace one after one of our T1s had it happen to him trying to service the dosing injector.

 

Go to the thread "warranty answers".I posted this post there.

 

We have never really had to service the doser injectors. Because of the location and the fact that it is the updated style, they rarely, if ever plug up. Its not like an 871 cummins where they regularly plug. We dont offer it as a preventative maintenance. I have only ever cleaned a handful on 2250s even. I would just leave them alone. Clean when you do a dpf clean/change. I assume you have tried heat and tapping the heads with a hammer to break the rust. Also what coolant fittings are you referring to? The ones on the egr venturi??