400 Hp Cummins engine

[TQUIN45]

I am new. We have a new last summer 2007 Winnebago Vectra 40 TD. Driving back from Yellowstone our 8.9 L 400 Hp Cummins had a problem. After starting in the morning we had very low power driving up an entrance ramp- turns out the Turbo was not putting out sufficient pressure. After the engine is warmed up (25 miles of driving) if you turn it off and then restart all is ok. Did this consistantly 5 times that week even when cummins looked at it. Does anyone have an idea what could be wrong- by the way there are no bad codes being recorded. Cummins does not have the answer yet. We did drive it home from Wyoming to New England. Thank you for any help. The vehicle has 11000 miles now. Normally it runs great.
TQUIN45

[Diplomat Don]

Just a thought....have you checked all of the connections on the Charge Air Cooler (hose clamps). You may have a loose clamp and after everything heats up there is enough expansion to seal the leak.

Another thought would be the exhaust brake is sticking partially closed. Has it been lubed since new?

[RickO]

Welcome to the forum! Sorry you're having trouble with your rig. We have the same engine and it's been pretty solid for us. It sounds very weird that it wouldn't be generating any error codes and that Cummins can't locate the problem. If I read your post correctly, it sounds like your Vectra may have sat on a dealer's lot for quite some time so I wonder it this will ultimately be a contributor.

Please keep us posted on what you find out.

[bad1032]

When I bought mine i had the same problem, once you got up to 55 it would run ok, but had no boost, took it to the cummins dealer and they had to reflash the ecm to get it to run. Still think it may be down a lil bit but it will boost to 36 lbs,

[TQUIN45]

Hi again- I just brought the RV to a FreightLiner dealer back here in NH. The problem with the power or Turbo is still there. Hopefully the dealer can solve the problem and fix it quickly.
I would like to thank Freightliner and specificly Dwayne (Customer service representative) for their endless help. Before our trip we had some minor questions and during the trip after the engine problem they have worked hard at trying to fix the problem. My only issue is while we were stuck in Milton Ill Cummins would not allow the Cummins mechanic to install a new ECM, which he thought was the cause of the issue. Cummins insisted the ECM was okay and wanted a whole array of tests (testing tree) to be done before any replacement of parts.(the Freightliner dealer in Milton was very good to work with) I do understand Cummins position and given the time and money I would do the same but we were trappped 1500 miles from home. Sometimes you need to take an educated guess for a potential quick fix to releive the position the customer is in. We did make it home okay and now it is at dealer number 2. I will keep this board informed of the solution.

[bad1032]

Good luck I hope they get it straigh, I know i was pissed with mine, Brand new 2010 and it wouldnt get out of its own way, They had to do the same thing follow the flow chart check this and that, they ended up reprograming the ecm and so far its better.

[Gary - K7GLD]

Often a sensor will cause that - the MAP sensor would be my first guess - it's the one that senses intake manifold pressure, and signals the ECM as part of the control group...

The IAT - Intake Air Temperature sensor is another...

[Navy Flier]

As with many things we deal with your engine is controlled by a computer. When you restarted your engine to get it to work properly it was just like rebooting your home computer. I think that in the end you will find the problem in the computer. I am surprised that the two shops have not tried to flash the ECM as it is a quick and simple effort. Also, since your unit is 3 years old, do you know if all of the ECM updates have been installed? If not, that may solve the problem. Finally, while there are no bad codes have they looked at the computer readout for the last six months. That should give the techs a starting point and maybe a pointer or two. I would suggest that, if you have not, you should call the Cummins customer service line and make sure they have all of this documented. If I have an engine problem that is the first call I would make. I am fortunate to have a dealer, a Freightline shop, a Cummins shop, and an Allison shop where I live and, if necessary, I can go to the Cummins shop for any engine issues.

[Jerry J]

I don't know what your problem is but August 2010 heading into Denver we had the message "Stop Engine". Short story is we went to Rocky Mountain Cummins in Henderson, Co. for service. Lucky we were close. They replaced the turbo actuator because we were down on power although I didn't notice it so much because we were in traffic. Fault code was 2636. KIT, VG TUR ACT SERVICE - #4032768, lucky to still be under warranty.
Let us know what the actual problem and solution is. We do have fun with our TD's don't we.

Quote:

Originally Posted by TQUIN45 I am new. We have a new last summer 2007 Winnebago Vectra 40 TD. Driving back from Yellowstone our 8.9 L 400 Hp Cummins had a problem. After starting in the morning we had very low power driving up an entrance ramp- turns out the Turbo was not putting out sufficient pressure. >>>>>>>>>>>> TQUIN45

[TQUIN45]

Hi -Thank you to all that have come back with their advice and experience. We just picked it back up from the Freightliner dealer- not fixed yet. They said it was fixed on the 2nd day -changed the fuel filter but after going up and driving it with them they learned it was not fixed. I beleive that once they get the ok from Cummins they will reload the software in the ECM. This issue does require the vehicle to be run until warm , turn it off, wait at least 1 min, and then restart it to fix it. If recycled before it is warmed up it does not fix it. Big difference with and without the Turbo working correctly. Both Freightliner and Cummins have been very good at trying to fix it- a little slow but they are working the issue.
Thank you all again.
Tom

[Flyer]

Tom
I had a similar problem with my ISL which was hard to diagnose. It turned out that the pacbrake valve was sticking closed. It would happen when the engine was cold. When the valve closed going down a grade it would stick closed and when accelerating would not reopen. After shutting down things would heat up and the valve would reopen on its own. This problem stumped Cummins because it did not throw a code. Symptoms were lack of power and black smoke coming out the exhaust (too much fuel-not enough air). Pacbrake replaced the valve and I had to pay the labor.