c2 thomas safe-t-liner 2009 overheating exhaust, engine stop every 30 min

[agoodsnail]

we have a c2 thomas safe-t-liner 2009, cummins 6.7 engine

were on a 10hr road trip. 2hrs into the trip the stop engine light and overheating lights came on. coolant levels low, found an autozone, topped off coolant, got back on the road. same problem 30 min later.

again, autozone. coolant lower but not much. so we top off pt2. this time we decided to do a diy loop of the coolant tubes that led to the old rear heater and to open the valves so that it circulates to back there and loops back (why not? idk)

20 min later same problem. engine off, exhaust overheating light. ****.

brought to deisel mechanic in AM. they tested our pressure and replaced thermostat housing and water pump.

also fixed a transmission fluid leak that was happening in connection to radiator by tightening a valve. woohoo!

30 min later on the road, same issue.

back to mechanic. next day they connect to computer system and saw some part of our exhaust was clogged up? egr i think... something they were able to clean w a paper clip? sent us going and same exact spot 30 min later we overheated. we noticed some black soot coming out of the exhaust for 1 second upon stopping.
which implies clogged filter, i believe.

this time were just gonna fuckin keep going and get to a mechanic closer to our destination that can replace the dpf. we went 1.75hrs with no issue. just stopped for lunch and went 20 min w same situation. black smoke comes from exhaust with reving now.

what do yall think. dpf fuckin up?

other info: bus has been on one 10hr road trip before w no problems in spring time (so if its a problem that has existed....only factor different now is the temperature outside). this is 1 year ago. we havent been good about restarting it, probs been started once every 4 months if even that tbh.

thanks for your time and help in advance.

PS. if you have a c2 thomas PM us. id like to start a whatsapp group with all of us in it.

[Rwnielsen]

You mention "DPF"....diesel particulate filter? If so, I believe you need to add diesel particulate fluid in a separate tank. Also there's a "regen" procedure that, from what I can tell, burns off the residues on the filter. This is from what I've gathered reading and is in no way actual, practical, experience. Maybe that is clogging up your exhaust, causing excess back pressure. Please wait for a more knowledgeable person to step in before you do anything costly.
Best of luck to you

[agoodsnail]

from what i understand DEF engines and DPF engines are different. DPF is a filter and does a regen process to stay clean, while DEF involves putting special fluid into your bus on a regular basis.

we dont have a separate tank labeled DEF nor do we have a DEF fluid gauge so i assumed we have a DPF system

[Rwnielsen]

There's a ton of experienced people on this forum, you should be getting some good info shortly

[cadillackid]

a DPF is as nielson says, a filter.. ..DEF is diesel exhaust fluid.. if your bus uses it (not all DPF equipped diesels used it in the first few years).. you would have a separate fill for it.. and if it is the issue (running out).. the LCD display in the cluster would show you.


Regem is the process where the filter tries to clesan itself.. the dash should indicate it. . during a Parked-regen you will usually have a revving engine and black / gray smoke out the exhaust..



coolant loss.. are you still losing coolant? Clogged DPF and coolant loss are signs of the EGR cooler leaking in its water jacket.. or exhaust backpressure ending up in the coolant system which will bubble the coolant out the overflow and onto the ground...



if the mecahnic fixed your coolant leaks then thats likely not the issue.. (sigh of relief)


sometimes a DPF gets clogged enough that it needs to be taken off the bus and either replaced or cleaned (Baked) in a shop .. other times you can solve it by starting a parked-regen procedure a couple times and getting it to come back in service normally..


P.S. I should add if you have DEF you also have a DPF.. the DEF is used as an agemt to help clean the DPF..

[agoodsnail]

Originally Posted by cadillackid

a DPF is as nielson says, a filter.. ..DEF is diesel exhaust fluid.. if your bus uses it (not all DPF equipped diesels used it in the first few years).. you would have a separate fill for it.. and if it is the issue (running out).. the LCD display in the cluster would show you.


Regem is the process where the filter tries to clesan itself.. the dash should indicate it. . during a Parked-regen you will usually have a revving engine and black / gray smoke out the exhaust..



coolant loss.. are you still losing coolant? Clogged DPF and coolant loss are signs of the EGR cooler leaking in its water jacket.. or exhaust backpressure ending up in the coolant system which will bubble the coolant out the overflow and onto the ground...



if the mecahnic fixed your coolant leaks then thats likely not the issue.. (sigh of relief)


sometimes a DPF gets clogged enough that it needs to be taken off the bus and either replaced or cleaned (Baked) in a shop .. other times you can solve it by starting a parked-regen procedure a couple times and getting it to come back in service normally..


P.S. I should add if you have DEF you also have a DPF.. the DEF is used as an agemt to help clean the DPF..

word were gonna take it to a deisel mechanic ASAP to get the DPF looked at.

we had it running w no overheating for a solid 2 hrs and were almost to our destination now. its been runnin smooth but with a check engine light on. no more engine shut off/exhaust oveheat lights tho

my concern is that at no point is the regen light on indicating its doing the process. weve tried to click the button as well and nothing happens. so maybe something is wrong w our regen system?

at one point the bus was spewing black smoke after it shut off from overheating and it kept smoking w every rev. this stopped after we parked and let **** cool for 20 min.

will def be updating w the resolution when we get it!

[cadillackid]

it may not go into Regen unless the regen light is on.. but you asre supposed to have the engine warmed up to operating temperature, be in neutral, parking brake applied, idling.. then hold down the regen button for 5 seconds.. if it needs to run one it will light or flash the regen light.. (at least this is how its done on a Bluebird 6.7 cummins,) freightliner / tho,as should be similar

[jby5010]

A quick add to Cadillac Kid's post; to do a parked regen:
Start the bus
once air pressure is up and temp is up, cycle the Parking brake off then back on
then move gear selector to drive or reverse and back to neutral
Then you can press the Regen button for a couple seconds. It should idle up to 1200 or 1500 rpms if it started.

[agoodsnail]

ok ok ok heres the update.

we went to a mechanic nearby. they said "your dpf is cracked fo sho. we tried a regen and it failed. youre giving out black smoke on accelration consistently. computer not giving any useful codes. we think the dpf was cracked by some nonesense going on upstream. its either the turbo or the injectors. you need your dpf replaced AND either turbo or injectors or both replaced and we wont do it so go to a Cummins dealership and get it warrantied"

upon some research weve found that our engine (cummins 6.7....my b if i said 8.3 earlier i was WROOOOONG) has historically faulty turbos and faulty injectors?

so now we have an appointment at a cummins dealership a week from now for THEM to troubleshoot it and hopefully fix it.

the bill...is going to be...ridic.

will post a final final update when all the **** is settled and were officially bankrupt