19 replies to this topic

[Medeiros]

Purchased a 2012 Holiday Rambler Ambassador. At various speeds, motor home begins to surge (bucks) as I drive down the road. Does anyone else have the same problem? If so, have you been able to rectify it? Two trips to an International service center and two attempts to reprogram the transmission have not worked.

Any suggestions other than constantly "staying on" International and Navistar would be appreciated.

Clyde

[wolfe10]

Clyde,

Welcome to the FMCA Forum.

Please tell us what engine you have. Also, what transmission.

Is this bucking new or has it always done it?

How many miles on it?

[DickandLois]

Clyde,

Do you have the surging issue only when cruise control is on, or all the time?

Rich.

[Medeiros]

Rich,
The engine surges when I am both in and off of cruise control.
I previously owned a Monaco Diplomat that started doing the same thing when in cruise control. It was pretty much "fixed" but would occasioally do it to a lesser drgree than when it started. It would seen that that problem is following me no matter what I own.
Clyde

[Medeiros]

I have a 350 HP Cummins diesel. I have to check on the transmission. Right now the RV is at Alliance RV having some work done on it. When I get it back, I will let you know.

I bought the vehicle new and noticed the problem when I took it out on our first trip (no hint of problem on test drive), and it has been doing it ever since. I currently have 6700 miles on the engine.

Clyde

Note from Moderator: Further down in this thread, the OP said he has a Navistar, NOT Cummins engine.

[RVerOnTheMove]

Since this is a new unit under warranty from the manufacturer and the engine/chassis manufacturer, what has Cummins said about your problem?

[DickandLois]

Clyde, I go along with Bill that it should be checked out by Cummins. Fuel system issue tops my list.
Things that come to mind are Throttle control, bad connection or noisy position sensor on the gas pedal.
ECM, bad connection(s) bad circuit inside the module.
Fuel Injector pump, pressure issue.
Fuel lift pump, Pressure or air intrusion in the suction side
Fuel lines, loose or missing line clamp, a hole in the line--chaffing issue.
Filters, Dirt or other material in the fuel tank when it was installed, filter restriction.
Crank shaft sensor?

Rich.

[Medeiros]

Rich,
Thanks for the suggestions. It seems that Cummins thinks the problem is a transmission program problem. I've brought it to them twice, and they have, unsuccessfully, tried to reprogram it on both occasions. However, I am going to bring it to them, again, with the suggestions you made. Thanks for your help.
Clyde

[Medeiros]

Brett,
Thanks for your help. I am going to bring the RV back to Cummins, a third time, with the suggestions Rich made.
Clyde

[RVerOnTheMove]

Just keep taking it back (or if I were you, don't leave) until they get it right. There is no reason for you to suffer due to a problem you did not create. Make them make it right and then get back to enjoying the coach you paid such good money for. Accept no BS. Either it works or it doesn't. There's really no middle ground.

[cmarq]

Clyde, (my name is also Clyde) You say it surges both in and out of cruise control. I am going to assume you are at a highway speed. I worked for a Cummins distributor in the northeast and have seen this complaint in a truck. Too make a long story short it also had an Allison. After many reprograming and changes to ECM a dyno test with old fashioned gauges hooked to engine showed a restriction in the fuel system from debris in fuel tank. I would ask your Cummins dealer if they would chassis dyno and check fuel restriction at full load. There was not a power complaint or warning light or fault codes. Just the surge at highway speed.

[Koliver]

There is likely an Allison transmission service center nearby, where the Technicians will know more than the Cummins guys do about your transmission. If they say it is the transmission, they will fix it. You won't be left doubting whether they got it right, or thinking the Cummins guys are just blaming the transmission cause they haven't been able to properly diagnose your problem.

[wigginsjsr]

I am confused. Your original post stated that you had taken the coach to the International dealer not the Cummins dealer. Some of the 2012 HR/Monaco coaches have an International MaxForce 350 HP engine. My Monaco Knight has the International (Navistar). Are you sure you have a Cummins?

I have read, on this and other forums, about some surges with the Allison/Navistar combination. I don't remember the details.

[wolfe10]

Yup, TOTALLY different engine with very different emissions systems.

[Medeiros]

Clyde,

Thanks for the suggestions

I have to apologize for an engine mistake. My engine is an International by Navistar.

The problems I am having are at different speeds (on and off cruise control). It will surge at speeds around 25, 35, 45, 55, and 65 mph.. It varies. I can get it out of bucking by letting up on the gas or accelerating. I have been told that it is a problem that could, very likely, be solved by reprograming the transmission. The problem is meeting the government's emission control standards. Who knows. At any rate, if things keep going the way they have, I will definitely try what you have suggested.

Thanks for your help,
Clyde

[Medeiros]

I must apologize for my mistake. It is an International engene.
Clyde

[wolfe10]

Clyde,

Please post which Navistar engine you have. You might also Google that engine and "surge".

Brett

[Medeiros]

Bill,
Sorry for the late response and the misinformation on my engine. It is not a Cummins. It is an International by Navstar.

It seems that other owners have the same problem, and Navstar feels it is a problem with the transmission. They also feel that reprogramming it will solve the problem will. Unfortunately, they have tried to do it twice, unsuccessfully.

Clyde

[Medeiros]

Brett,

I have to wait to get the RV back. It is currently in the shop for some work. I am anticiating getting it back on Wednesday (11/28). I need to start becoming a bit more aware of certain things. Not being mechanical by nature, I reallly never pay attention to those things. I think I need to become a little bit more aware of certain things.

Clyde

[dkreuzen]

There was a recall for this issue back in June 2012. It is a update of the ECM. Campaign #12913.