ISB 300 Power loss / Turbo Failure
I have a 2004 Newmar Kountry Star with 69k miles. It's been a great coach and I have had no problems to date. On my last trip I noticed significant power loss, especially when climbing hills or tak...
Forum Discussion
Start with the filters, this is the most basic thing to do when you start loosing power, especially if the problem came on after refuelling. Also check the air filter, never know.
250 codes is a lot of codes. Ask them which codes, otherwise this is a shot in the dark. Then ask them what are the codes related to. At least, if they are not sure, ask them to clear the codes and run the engine or test drive the MH, then recheck the codes.
You have the same engine as mine, cummins ISB 300 HP 2003. Might be turbo sticking but I doubt it because this problem would likely cause an intermitent problem, sometimes it would stick, sometimes it would let go and work again.
The second thing on the turbo could be the electric motor that drives the VGT, variable vane, or the position sensor that tells the ECM what is the position of the turbo VGT. The VGT sensor can be replaced, if they do not have the sensor, they can take the one from the EGR to test it, same sensor. The electrical motor could stop working completly or could be intermitent. The wires to the turbo could also be at fault. If it is electrical, you should have a code that says low voltage/low current or no voltage to VGT.
A test can be done. If they are not able to make the VGT working with a test equipment, try this: While someone is turning the Key in the ON position but not starting the engine, as the key comes on, you should feel two cycle on the VGT, just put your hand on it. If you feel nothing, then there is a problem either with the motor or the wires, hope not the ECM.
If you have the DC electrical motor on the VGT, the motor is not servicable, according to cummins. Common cause to electrical motor is they get coolant bypassing the seal in the VGT mechanism, very poor design from cummins and very poor in solving recurent problems.
Turbo must be replaced as an assembly if motor is shot. The last price quoted from cummins to me was $3500.00. I would say it takes about 4 hours to replace. I could have a rebuilt one for $2000.00 and the other for $2600.00. I am checking right now to see if a VGT assembly can be bought separatly from the turbo.
Good luck, keep us informed.
250 codes is a lot of codes. Ask them which codes, otherwise this is a shot in the dark. Then ask them what are the codes related to. At least, if they are not sure, ask them to clear the codes and run the engine or test drive the MH, then recheck the codes.
You have the same engine as mine, cummins ISB 300 HP 2003. Might be turbo sticking but I doubt it because this problem would likely cause an intermitent problem, sometimes it would stick, sometimes it would let go and work again.
The second thing on the turbo could be the electric motor that drives the VGT, variable vane, or the position sensor that tells the ECM what is the position of the turbo VGT. The VGT sensor can be replaced, if they do not have the sensor, they can take the one from the EGR to test it, same sensor. The electrical motor could stop working completly or could be intermitent. The wires to the turbo could also be at fault. If it is electrical, you should have a code that says low voltage/low current or no voltage to VGT.
A test can be done. If they are not able to make the VGT working with a test equipment, try this: While someone is turning the Key in the ON position but not starting the engine, as the key comes on, you should feel two cycle on the VGT, just put your hand on it. If you feel nothing, then there is a problem either with the motor or the wires, hope not the ECM.
If you have the DC electrical motor on the VGT, the motor is not servicable, according to cummins. Common cause to electrical motor is they get coolant bypassing the seal in the VGT mechanism, very poor design from cummins and very poor in solving recurent problems.
Turbo must be replaced as an assembly if motor is shot. The last price quoted from cummins to me was $3500.00. I would say it takes about 4 hours to replace. I could have a rebuilt one for $2000.00 and the other for $2600.00. I am checking right now to see if a VGT assembly can be bought separatly from the turbo.
Good luck, keep us informed.
