egr valve removal

Ok, so it was working fine and for preventive maintenance you had Freightliner replace the EGR valve (not the EGR actuator), the intake throttle valve, and did they replace the HC doser block or injector?

If I remember correctly the re-gens on those engines ran 30-60 min. And anything less than 20 minutes usually ment some fault kept the regen from initiating.

It sounds like you either your truck is running correct now and it just never did the last 3 years or Freightliner wasn’t able to either; reestablish all electrical connections, or didn’t completely purge the air out of the HC (fuel) doser system.

Is it showing any check engine lights or can you pull any codes from your truck. If it’s not completing a regen there should be a code.

 

Normally you can’t initiate a parked regen unless it asks for one with the flashing indicator on the dash. So, It sounds like your exhaust or engine temps aren’t reaching the desired. And it disables the regen.

If your engine is reaching at least 170deg on the coolant gauge. My best guess is you have a problem in the doser system. Either it wasn’t fully purged, they installed a faulty control block, or your doser/injector is plugged.

Could also be that they flashed newer software to the MCM and that’s why it’s acting different. But either way you’ll have to convince a guy with a computer to believe you and have enough luck that they’ll see the problem...

 

Try removing the injector and stick something like a philips screw driver in the hole to remove any soot build up. That could be the cause of the filters not reaching temp.

 

You will need two handwrenches a 14 mm and a 12 mm to remove injector.

 

Is it not regening because everything is good? If it’s not because there’s an issue. I would look into changing the imap and the differential pressure sensor and maybe the dpf inlet temp sensor

 

My question is did the Mechanic clean the EGR Ports before he just slapped a new EGR valve on it? There will be no sense in replacing the Differential Pressure sensor if the tubes that feed the exhaust to it aren't clean. That will mess with a regen if the EGR pressure isn't correct. Also if the air supply over to the 7th injector/block/doser isn't pushing the fuel to it, it will not burn hot enough for the regen to continue. Short unfinished regens are twice the soot and ash on your DPF, I would check the fuel/air control module that supplies the Injector/Block once the EGR ports/tubes are clean of soot.