Exhaust Brake Quit

[DBradham]

08 3500 MegaCab 6spd auto 16000 miles..... a couple thousand miles ago I had to have the ECM changed... . I live in Alaska and one morning at -50 F the truck started. . sounded wierd and died. The dealer couldnt tell me why it failed, it probable froze to death. Anyway I always turn the brake on to aid in warming it up and have noticed that the last couple of weeks upon driving the eb seemed to be jerking when it engaged??? Kind a like a mild quick downshift but you could tell it wasnt in the transmission and it didnt sound like its supposed to,you know . . that sound that turns heads and makes me chukle argggge. Now the eb doesnt work at all and I got a CEL. Could the eb be freezing up. I have the truck cleaned regularly and have the belly sprayed down..... the roads up this way can get your rig extremely grimy and the only way to clean them is going through a brushless car wash with under belly spray down then driving down the road in -20F. After one of these cleanings could it be possible that the eb is just freezing up and it trying to do its job while frozen is too much for it to handle?

 

[Coalsmoke]

Well there is nothing mechanical on the EB that is open to the elements, so I wouldn't think it should be icing up, but maybe the cold is playing havoc on it. It sounds sort of like more of an electrical malfunction to me.

 

[Hoefler]

Check for codes. You probably have a P2262. Sounds like the turbo is soot-ed up and needs cleaning or replaced.

 

[HBarlow]

Yeah, I agree that your turbo may have sooted up. Your 6. 7 engine doesn't actually have an "exhaust brake" like TDR members normally speak of.

What you have is a sliding turbocharger nozzle that provides full boost when the turbo nozzle is extended all the way in one direction and when extended fully in the other direction it provides blocked exhaust discharge and functions like an exhaust brake.

If you don't drive it hard enough to occasionally call for full boost then full braking you may have a sooted up turbo and it is binding.

 

[AHarris]

Is keeping the exhaust brake on all the time enough to avoid the turbo sooting problem? I don't drive my truck very hard.

 

[Coalsmoke]

Yeah, I agree that your turbo may have sooted up. Your 6. 7 engine doesn't actually have an "exhaust brake" like TDR members normally speak of.



What you have is a sliding turbocharger nozzle that provides full boost when the turbo nozzle is extended all the way in one direction and when extended fully in the other direction it provides blocked exhaust discharge and functions like an exhaust brake.



If you don't drive it hard enough to occasionally call for full boost then full braking you may have a sooted up turbo and it is binding.

Just to be clear, these engines DO have an exhaust brake, as opposed to something like a compression retarder. They function a bit differently than the butterfly valve style, but the principles are the same behind it and its still classed as an exhaust brake.

 

[HBarlow]

Just to be clear, these engines DO have an exhaust brake, as opposed to something like a compression retarder. They function a bit differently than the butterfly valve style, but the principles are the same behind it and its still classed as an exhaust brake.

Are you just arguing semantics?

I guess you can call it an exhaust brake if you want but to do that you'd have to be unfamiliar with or unaware of a traditional exhaust brake like the Jacobs.

If your 6. 7 liter Cummins engine has an exhaust brake it is the only one ever produced that does. I think you're getting your terminology confused.

Our 6. 7 engines have a variable geometry turbocharger that, operating as I described in my earlier post, performs the same function as an exhaust brake. Its design and operation are entirely different than a traditional external exhaust brake. An external exhaust brake closes a butterfly downstream of the exhaust manifold.

A compression retarder is an "engine brake", not an exhaust brake.

 

[DBradham]

Just got back from the dealer

The CEL had a "bad temp sensor code" set. Now as stated in the beginning I typically use the eb to help warm the engine. I rairly use it in the winter after warm up as the roads are VERY icy and sometimes your driving on a few inches of packed snow. To use the eb in these conditions could cause the back wheels to lose traction when engaged. I do drive it hard enough to hear the turbo spooling up all the time. In AK you can go from sea level to a couple of thousand feet in no time (big mountains). The truck has never flashed the regen warning on the overhead consol. If the turbo was sooting up wouldnt I get a regen warning too? In a previous thread I read that the eb can be used to facilitate warm up and then when the temp reaches a certain point it cuts off. Would a bad temp sensor cause the eb not to function do to a bad temp sensor and nothing be wrong with the eb/turbo???? Is there an easy way to clean the turbo and not have to take it to the dealer... . Ive got a competant dealer but they are REALLY SLOW.

 

[Coalsmoke]

Are you just arguing semantics?



I guess you can call it an exhaust brake if you want but to do that you'd have to be unfamiliar with or unaware of a traditional exhaust brake like the Jacobs.



If your 6. 7 liter Cummins engine has an exhaust brake it is the only one ever produced that does. I think you're getting your terminology confused.



Our 6. 7 engines have a variable geometry turbocharger that, operating as I described in my earlier post, performs the same function as an exhaust brake. Its design and operation are entirely different than a traditional external exhaust brake. An external exhaust brake closes a butterfly downstream of the exhaust manifold.



A compression retarder is an "engine brake", not an exhaust brake.

Don't get flustered, I'm just pointing out that these engines do have an exhaust brake but it is of a different design then what you are used to seeing. Just because it has a VGT doesn't mean it has braking capabilities.

 

[HBarlow]

I've never lived in Alaska but did visit and tour as much of it as I could in summer of 2004 pulling an RV trailer. I remember the "hills. "

I can't answer your questions about the causes of a CEL or about whether a bad temp sensor would cause a turbo malfunction. Maybe a knowledgeable dealer tech like sag2 will see and respond to your post.

I would also assume as you did that if the turbo was sooting enough to bind it should set a code.

My understanding is that '07. 5 trucks that have been updated by dealers and all '08 p/up 6. 7 engines have a hole drilled in the turbo housing to facilitate turbo cleaning but haven't seen one nor am I familiar with the procedure. My truck is a C&C with different hardware and software. My guess would be it would require the expertise of a trained Cummins tech to perform the cleaning but if you could get a set of instructions from a dealer and are a skilled mechanic yourself maybe you could do it.

 

[Hoefler]

The CEL had a "bad temp sensor code" set. Now as stated in the beginning I typically use the eb to help warm the engine. I rairly use it in the winter after warm up as the roads are VERY icy and sometimes your driving on a few inches of packed snow. To use the eb in these conditions could cause the back wheels to lose traction when engaged. I do drive it hard enough to hear the turbo spooling up all the time. In AK you can go from sea level to a couple of thousand feet in no time (big mountains). The truck has never flashed the regen warning on the overhead consol. If the turbo was sooting up wouldnt I get a regen warning too? In a previous thread I read that the eb can be used to facilitate warm up and then when the temp reaches a certain point it cuts off. Would a bad temp sensor cause the eb not to function do to a bad temp sensor and nothing be wrong with the eb/turbo???? Is there an easy way to clean the turbo and not have to take it to the dealer... . Ive got a competant dealer but they are REALLY SLOW.

You would not get a re-gen notice unless you are 80% full or greater. It is recommended to run the exhaust brake at all times when conditions permit. Getting the turbo hot and keeping it there is the challenge. The 6. 7 needs to be run hard to generate the heat needed. I have had the cleaning done, and then the turbo replaced. I tow 90% of the time, about 6,000 pounds regularly and 16,000 occasionally. Where I live, there is nothing flat. Since the turbo swap, I have been trouble free. I guess the short of it is, run in tow/haul, exhaust brake on, and drive it like you stole!

 

[Pat@BD]

Are you just arguing semantics?



I guess you can call it an exhaust brake if you want but to do that you'd have to be unfamiliar with or unaware of a traditional exhaust brake like the Jacobs.



If your 6. 7 liter Cummins engine has an exhaust brake it is the only one ever produced that does. I think you're getting your terminology confused.



Our 6. 7 engines have a variable geometry turbocharger that, operating as I described in my earlier post, performs the same function as an exhaust brake. Its design and operation are entirely different than a traditional external exhaust brake. An external exhaust brake closes a butterfly downstream of the exhaust manifold.



A compression retarder is an "engine brake", not an exhaust brake.

Not trying to sound petty here, but Dodge refers to it as an exhaust brake in all of their literature and on their website. It is an exhaust brake. It uses exhaust back pressure to create exhaust braking. It might not be the traditional style we are used to, just newer technology. Dodge isnt the only one that uses this same technology. Most of the medium duty GMs with the newer 6. 6 have an exhaust brake that closes the slides a collar over the turbo nozzle to create back pressure.



That being said the problem is most likely going to be a carbon build up. It is pretty common on these. Your dealer will most likely just replace the whole turbo assembly.

 

[HBarlow]

When someone is talking about the exhaust brake function in an attempt to diagnose the cause of the loss of exhaust braking as was the original poster it only leads to confusion to call it an exhaust brake. There is no butterfly valve in a housing downstream of the turbo as in traditional exhaust brakes therefore the possible causes of a malfunction are entirely different.

Dodge refers to the exhaust brake function in marketing material to let customers or prospects, many of whom know little or nothing about diesel engine components but have heard of magical exhaust braking know about a feature included.

The 6. 7 engines do not have an exhaust brake in the traditional sense. The engine uses the variable geometry turbo to perform the same function as a traditional exhaust brake.

 

[Pat@BD]

When someone is talking about the exhaust brake function in an attempt to diagnose the cause of the loss of exhaust braking as was the original poster it only leads to confusion to call it an exhaust brake. There is no butterfly valve in a housing downstream of the turbo as in traditional exhaust brakes therefore the possible causes of a malfunction are entirely different.



Dodge refers to the exhaust brake function in marketing material to let customers or prospects, many of whom know little or nothing about diesel engine components but have heard of magical exhaust braking know about a feature included.



The 6. 7 engines do not have an exhaust brake in the traditional sense. The engine uses the variable geometry turbo to perform the same function as a traditional exhaust brake.

I work for an exhaust brake manufacturer. True they are not the traditional style butterfly valve in the exhaust down stream brake that we are used to. But just because it is actuating a different way to accomplish the same thing, exhaust braking, doesn't mean it isn't an exhaust brake. Take televisions for example. The technology from about 20 years ago has changed a lot. The end result is the same, a picture on a screen to look at. Just because it doesn't use the old tube technology doesn't mean the new ones aren't a tv.

 

[Coalsmoke]

Pat, I am now reminded why I try to avoid topics with Harvey in them. You can be completely correct, lay out all supporting evidence, and do your best to correct something but in his mind it will never change until he accepts that he may be mistaken.

 

[Pat@BD]

Pat, I am now reminded why I try to avoid topics with Harvey in them. You can be completely correct, lay out all supporting evidence, and do your best to correct something but in his mind it will never change until he accepts that he may be mistaken.

I am not trying to be right or wrong, just trying to keep it so there is no confusion. :-{}

 

[Coalsmoke]

Have at er, I didn't say you have to stop trying to clear things up, just that I've already been there posts 2 through 9 and don't be too offended if it doesn't clear anything up.

 

[HBarlow]

08 3500 MegaCab 6spd auto 16000 miles..... a couple thousand miles ago I had to have the ECM changed... . I live in Alaska and one morning at -50 F the truck started. . sounded wierd and died. The dealer couldnt tell me why it failed, it probable froze to death. Anyway I always turn the brake on to aid in warming it up and have noticed that the last couple of weeks upon driving the eb seemed to be jerking when it engaged??? Kind a like a mild quick downshift but you could tell it wasnt in the transmission and it didnt sound like its supposed to,you know . . that sound that turns heads and makes me chukle argggge. Now the eb doesnt work at all and I got a CEL. Could the eb be freezing up. I have the truck cleaned regularly and have the belly sprayed down..... the roads up this way can get your rig extremely grimy and the only way to clean them is going through a brushless car wash with under belly spray down then driving down the road in -20F. After one of these cleanings could it be possible that the eb is just freezing up and it trying to do its job while frozen is too much for it to handle?

As anyone can see, the original poster was inquiring about the possibility of his "eb freezing up" after discussing cold temps and spray washes.

It seems to me that clarifying that there is no "exhaust brake" in the traditional sense but a VGT that performs the function of an eb on these trucks helped the op to answer his question.

 

[Hoefler]

As anyone can see, the original poster was inquiring about the possibility of his "eb freezing up" after discussing cold temps and spray washes.



It seems to me that clarifying that there is no "exhaust brake" in the traditional sense but a VGT that performs the function of an eb on these trucks helped the op to answer his question.

Whether it is a VGT, Butterfly, or a Potato stuffed in the the tail pipe, they all do the same thing, stop or greatly restrict the flow of the exhaust. By any definition, it is still an exhaust brake.

 

[DBradham]

Sliding Vanes

OK Im back... ... makes perfect sense that the exhaust braking is performed by restricting the hot gas flow by a sliding vane on the hot side of the turbine Does the turbo gets its exhaust boost from a upper deck pressure controller signaling waste gate actuation??? Is this a sea level turbo or does it have the ability to push manifold pressure over 29. 92"? Cummins could possibly fix this problem by installing a poppet valve before the intercooler..... let the turbo boost all the time so it will stay hot and wont coke up and let the poppet take care of the unwanted boost when the engine isnt calling for it..... EGT probe the exhaust gasses (before and after turbo) to send a signal to the computer to allow it to stay at a perfect opporating temp As stated before my dealer said the CEL showed a bad temp sensor. They said it was OK to drive and they would look into the engine brake (exhaust brake:-laf)and bad temp sensor when the parts come in for H36 recall. What concerns me is that the truck only has 16000 miles on it and it may need a new turbo? The warranty runs out @ 300000 I believe... . and my pocket book cant aford to replace turbo's every 16000 miles. I absolutely LOVE the truck and would like to keep it..... but wil dodge continue to work out the bugs for free