Cummins Re-gen system

This topic contains 2 replies and was last updated by ed-snippe-2 8 years ago
April 13th, 2013 2:09am
I am working on a freightliner van type unit with 6.7 cummins in it . I am having temp related issues with the re-gen system.unit will not re-generate. I have traced two coolant lines coming from engine to a block in left frame rail, the block has four lines attached to it two that go to the def fluid tank and to that go to the burner unit.the two small lines going across to burner unit are same temp as supply line and return from engine.the two lines going to the fluid tank are stone cold .yet entire block where they all connect is operating there some kind of relay or switch that controls flow of coolant through the lines that go through the tank or should those two lines be at operating temp as well any time that engine is running at operating temp? I am assuming the coolant runs through a core of some kind to warm the fluid in the tank. If there is someone with experience on this system i would greatly appreciate any suggestions or assistance you could offer me in resolving this issue .thanks in advance Ed
April 24th, 2013 1:19am
Ed, unless you are operating in very cold conditions I don't think the coolant lines are needed to keep the def fluid from gelling. I don't have any experience with the Cummins regen system but I thought I would reply anyway since no one else has. I would start with the nozzle that injects the def fluid into the exhaust stream. Remove it and try cleaning it with a carb cleaner type product. Good luck.
May 17th, 2013 12:19am
It would help to have the engine serial number. The DEF fluid is for cleaning the exhaust emissions of diesel powered engines. It is injected into a SCR chamber which is ahead of the Diesel Oxidation Catalyst (DOC) and Diesel Particulate Filter (DPF). The DEF fluid has nothing to do with the regen process. The regen process takes place in the DOC and the ash is stored in the DPF which is generally attached to the DOC and eventually will need to be serviced/cleaned. Short answer is your DOC face plate is plugged or damaged, but that should set a code or your DOC is damaged due to overtemp. If there is soot at the tailpipe this is usually an indicator that the DOC has failed. To achieve regen the exhaust is significanlty heated. Cummins does this by injecting extra fuel to heat DOC to around 1200 degrees Farenheit to incinerates the particulate matter and soot into ash. I hope this helps answer your question.

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