Major Engine Troubles - What would you do?

[Bryan H]

Ok, have fairly new to me 2008 Winnebago Destination with the 6.7 ISB. I bought it back in April of this year. First few months were bliss. However, I started getting an intermittent check engine code that indicated an EGR problem. The code would typically clear in 5-10 seconds and didn't seem to impair driveability. I finally had the opportunity to get the coach into Cummins (Mesa, AZ). The diagnosis was disappointing, to say the least. They are saying the turbo has failed (not total failure mind you, just whatever mechanical components control the variable geometry feature - i.e. it will still generate boost, although I guess it won't generate boost properly under high load conditions. Note that I was seeing around 26 lbs under load, so I'm a bit confused here). They went on to say the turbo failure resulted in an excessive rich condition that likely fouled the EGR, causing it to fail. Finally, the particulate filter was then polluted and plugged from the engine's poor operation. Oh yeah, a small exhaust manifold leak between cylinders 2 and 3 was thrown in for good measure.

Total repair bill is $4800, minus 10% for being a Cummins Power Club member. What are your thoughts? Would you get a second opinion? The guys I've been working with at Cummins Mesa seem very knowledgable and fair, but $4400 is a lot of money. They diagnosed the issues by first pulling the engine codes, but then followed Cummins procedures to physically check the parts (i.e. they tried to manually cycle the EGR valve and also somehow tested the turbo - they said both components failed and need replaced).

Thanks for your words of wisdom.

Bryan

[adonh]

Originally Posted by Bryan H

Ok, have fairly new to me 2008 Winnebago Destination with the 6.7 ISB. I bought it back in April of this year. First few months were bliss. However, I started getting an intermittent check engine code that indicated an EGR problem. The code would typically clear in 5-10 seconds and didn't seem to impair driveability. I finally had the opportunity to get the coach into Cummins (Mesa, AZ). The diagnosis was disappointing, to say the least. They are saying the turbo has failed (not total failure mind you, just whatever mechanical components control the variable geometry feature - i.e. it will still generate boost, although I guess it won't generate boost properly under high load conditions. Note that I was seeing around 26 lbs under load, so I'm a bit confused here). They went on to say the turbo failure resulted in an excessive rich condition that likely fouled the EGR, causing it to fail. Finally, the particulate filter was then polluted and plugged from the engine's poor operation. Oh yeah, a small exhaust manifold leak between cylinders 2 and 3 was thrown in for good measure.

Total repair bill is $4800, minus 10% for being a Cummins Power Club member. What are your thoughts? Would you get a second opinion? The guys I've been working with at Cummins Mesa seem very knowledgable and fair, but $4400 is a lot of money. They diagnosed the issues by first pulling the engine codes, but then followed Cummins procedures to physically check the parts (i.e. they tried to manually cycle the EGR valve and also somehow tested the turbo - they said both components failed and need replaced).

Thanks for your words of wisdom.

Bryan

$4,400 is a lot of money for sure. Where would you get a second opinion from.

[ka7suz]

Bite the bullet and let Cummins take care of it. Who else will be so particular in making it right?

JoAnn

[Bryan H]

Both good points. I don't know who else I'd take it to, and Cummins hasn't given me any reason not to trust them. My gut says have them do the work, I'm just wanting opinions whether or not you folks think that is a rash decision and I should be looking into this further.

[Pelledan]

Had the same thing happen to my 06 Journey with a 5.9ISB. The new turbo blossomed into a new turbo plus exhaust manifold when stud fasteners broke off in the manifold during turbo removal. Total bill was $4500 but most of it was absorbed by the extended warantee I had renewed 8 months earlier and that single expense ended up paying for the cost of the entire warantee. The ironic part was when the Check Engine Light came on AGAIN only 3 weeks after the new turbo went on. The new turbine speed sensor had failed that came with the new turbo. They replaced the speed sensor no charge but billed Cummins warantee service $400 for the replacement.

Dan

[Mekanic]

I think your bill is major but I'm Not sure I'd call the problems or the repairs Major. Not always but sometimes a sticking turbo Can be cleaned as can a DPF. Of course a dealer wouldn't ever tell you this or you might figure others with less knowledge or you yourself could do it and cut out their profit.

Related
I have cleaned more than a few idle air control valves on gas Fords engines with a $7 can of Throttle body cleaner and of course the dealer Fix was a $150 bill to install a new one.

[Bryan H]

I too have cleaned the iac many times on a mustang I owned previously, but I don't think a failed turbo or inoperative EGR fall into the simple 'spray with carb cleaner' repair regime, do they?

The service manager described the turbo as being seized, and yet I know it still generated boost. I have very little understanding of how VGT's work. Can the component the varies the aspect ratio be seized and yet the compressor still be operative? I had noticed a bad lag right off idle, so that may explain it.

[Wayne M]

Bryan,
So sorry to hear about this. As you well know I have the same MH and engine. I only hope that should something like this happen that my GS ESP would help.

Let us know how you deal with it. (And the final cost.)

Thanks.

[Pelledan]

The turbine vanes on a VGT open and close via a small 12 volt motor whose lever position is controlled by the ECM with inputs from the engine speed, throttle position, and boost pressure sensors and probably from a few other emissions based sensors as well. At low speed acceleration, the turbine vanes are positioned by that motor to grab all the exhaust flow possible causing the turbine fan to spool up very fast. This causes the compressor fan to do the same, thus creating maximum boost for the given low engine speed peramiters. Before VGT technology, fixed pitch vanes were similarly propelled by the engine's exhaust, but turbo lag was significant because the turbo had to wait for the exhaust to build to start creating boost pressure, plus a waste gate was employed that would channel excess boost pressure out the exhaust to eliminate the possibility of overspeeding the turbo. VGT turbos are more of an exact science in boost technology and with direction from the ECM with sensor input, will create the correct amount of boost for any given engine speed and load situation. It's the turbine vane ring, that part that all the vanes are connected to, that tends to coke up and doesn't allow the electric motor to change its position. The result is a fixed position turbo that will still generate boost from whatever position it was frozen in (or temporarily stuck in) but it is not generating the amount boost necessary for the engine to operate at its designed efficiency. When that happens, the light comes on. When it gets unstuck (however temporarily) the light goes off.

Dan

[jerichorick]

That is a great explanation Dan. Is there any way to prevent this from happening? A fuel additive maybe?

[Pelledan]

Jerichorick I wish I had a good answer for you but I don't. I worked in diesel R&D for 35 years and rarely saw this happen on test engines. I'm told that MH applications are more prone to this because of long off cycles, but my guess (and it's purely a guess) is that most people don't allow the turbo time to cool down after a high load situation as would be coming off road speed into a rest area. Since I bought my coach used it's a difficult call as I don't know how the original owner operated it. I do allow a 5 minute cool down before shutting the engine down and if my turbo fails again, I'll know (and will report to this forum) that lack of cooling down wasn't the cause.

Dan

[jamesrxx951]

Originally Posted by Bryan H

I too have cleaned the iac many times on a mustang I owned previously, but I don't think a failed turbo or inoperative EGR fall into the simple 'spray with carb cleaner' repair regime, do they?

The service manager described the turbo as being seized, and yet I know it still generated boost. I have very little understanding of how VGT's work. Can the component the varies the aspect ratio be seized and yet the compressor still be operative? I had noticed a bad lag right off idle, so that may explain it.

The turbo charger the Ford/International for the 6.0L was made by Garrett. Not sure who makes the one you had but if they suffered from VGT issues, it was usually do to some rust build up from sitting. The repair was to disassembly the turbine side of the turbo and clean it out. Since you are making boost, it appears your turbo is working fine just the VGT side is seized. I would look into having it cleaned. The poster above said the VGT is controlled via a 12V motor. I have no idea if that is serviceable but if that is burned out, maybe the turbo can be cleaned and the VGT motor can be cleaned. Turbos are a pretty simple device and can be serviced. Just mainly depends on serviced parts and someone that would do it.

[Bryan H]

I'll ask for more info from the service manager. I suppose Cummins' fix to a failed vgt component would be total turbo replacement. But is it realistic to think the vgt component could be fixed by a shadetree mechanic such as me?

[Bryan H]

Originally Posted by Wayne M

Bryan,
So sorry to hear about this. As you well know I have the same MH and engine. I only hope that should something like this happen that my GS ESP would help.

Let us know how you deal with it. (And the final cost.)

Thanks.

Thanks for the sentiment Wayne.

[TXiceman]

Check Engine lights come on fro a reason. As soon as you get a Check light, you need to get the vehicle checked, even if the light goes out. There should be a code stored in the system computer. The longer it goes, the more l ikely the damage will increase.

Ken

[jerichorick]

Dan, thanks for your years of serving to make diesels more reliable. You have an understanding of the complexity of the components and their interaction with one another that far exceeds most of us. Any input you have is definitely worth listening to.

About the turbo cooldown issue? I have seen too many cautions in the owners manuals I have read and it only makes sense. When you come off the road that chamber must be hotter than a frying pan. We all know What happens to oil when it is dumped int a hot pan and left there searing. Crispy crust.

Another turbo killer seems to be the air filter. There are two discussions going on irv2 at the moment on this subject.

Is there a shelf life to an air filter? Is it common for one to fail after two years in service because of the glue it is made with?

Thanks for all of your input.

Rick

[Pelledan]

Jamesrxx951, you are correct in that the turbo can be disassembled and cleaned but I don't think it's something a back yard mechanic would want to get involved with. Anything dealing with exhaust has significant fastener concerns caused by repeated thermal cycles and the corrosion bare iron & steel are subjected to. Wringing off bolts & studs during disassembly is one of the major pitfalls in this type of work. Should that happen and attempts to remove the broken bolt with an Easy-Out or drilling and installing a Heilcoil fail, you’re stuck with a disassembled kit whose core return value may now be less than if it were handed in whole from the get go. It's a tuff call and a definite gamble for a novice to try and tackle. Cummins, like all other engine manufacturers, buys their turbos from a vendor and will not attempt a repair on a failed one. I'm sure there's is a liability concern on Cummins part with an in-house turbo repair that would be completely eliminated by replacing with a new or factory rebuilt turbo.

Rick, regarding the adhesive used in air filters, I have never heard of a filter shelf life due to adhesive degradation over age. About a year or so ago I had read on this forum where one filter manufacturer had a one-time production problem with a type of adhesive they used that caused pleating breakdown. I could understand a one-time thing like that, but to generate an across-the-board decree that all air filters should be replaced every 2 years to avoid this issue is a difficult pill for me to swallow. I just replaced my air filter after 4 years and 20K miles and there was absolutely no indication that the old filter had any problems at all.
Dan

[edgray]

Originally Posted by jerichorick

Dan, thanks for your years of serving to make diesels more reliable. You have an understanding of the complexity of the components and their interaction with one another that far exceeds most of us. Any input you have is definitely worth listening to.

About the turbo cooldown issue? I have seen too many cautions in the owners manuals I have read and it only makes sense. When you come off the road that chamber must be hotter than a frying pan. We all know What happens to oil when it is dumped int a hot pan and left there searing. Crispy crust.

Another turbo killer seems to be the air filter. There are two discussions going on irv2 at the moment on this subject.

Is there a shelf life to an air filter? Is it common for one to fail after two years in service because of the glue it is made with?

Thanks for all of your input.

Rick

RICK: With all due respect for your quest to learn all you can about air filters, you are already very active in those other 2 threads, both of which have "FILTER" in their titles. It is duly noted you are upset about "2 year glue" being used in air filters. Please don't "highjack" this thread. Instead, why not just provide a link to those discussions.

THIS thread is mostly about turbo charger issues and I hope it will STAY "on topic". THANKS,
Ed

[RustyJC]

Originally Posted by Pelledan

Cummins, like all other engine manufacturers, buys their turbos from a vendor.....

Cummins turbochargers are manufactured by Holset, a subsidiary of Cummins. Their VGTs do not use movable vanes; instead, they use a sliding nozzle ring to vary the area of the exhaust turbine exposed to exhaust gases.

Rusty

[David49]

I had the same engine in my previous MH. On one of our trips, I started getting the check engine light intermittently and for a short time, engine acted like it didn't want to spool up. When I got it to Cummins, they determined that the turbo actuator was failing. They planned to replace the actuator, but the 'kit' from Cummins did not include the gasket where it attaches to the turbo. From what I was told, the gasket wasn't included in the kit, nor was it available by itself. So, they replaced the entire turbo assembly. Fortunately, my extended warranty paid for itself with that one. After it was done, I was a really happy camper with much improved engine performance and fuel mileage. I would recommend biting the bullet on this one and let the Cummins folks do what they do best.