Apparently a new Onan generator is needed - no repair

[kmb1966]

My 2001 Itasca Suncruiser has an Onan Marquis Gold 7000 generator even though it is a 30 amp motorhome, not a 50 amp. Started giving a code 37, brought in to the Onan service center. Service center says debris in the engine, bent rocker arm, burnt valves, some damage to excessive HEAT. Despite all of my religious oil changes, exercising, filter changes and only 750 hours, the unit will cost over 1900 to repair. Can't see spending that much money on that old of a unit. Also, I never understood why the unit came with a Marquis Gold 7000, when a 5500 appears able to do the job. My unit has basement A/C where the 20 amp circuit is tied directly to the 1st compressor (pulls about 12 amps) and the 30 amp circuit is tied to the EMS 30 amp system for the 2nd compressor and the rest of the unit. The Onan 5500 would appear to be able to handle this setup fine, and the Onan 7000 produces more power, but I don't see how I could utilize that extra power with the way it is wired. New Onan 5500 is around $4,000 and a new Onan 7000 is another $1,000
I suppose I am going to go with a new Onan 5500 with new warranty. Onan service center says it can solve the heat problem with a modification to the bin door with a louver/vent and a heat shield. Still trying to get details before I pull the trigger on this deal. Opinions welcome. Thank you in advance.

[STBRetired]

My Onan 5500 will start both my rooftop 13.5K airs at the same time. It does not seem happy about it, but it will start both units. I usually try to avoid that situation.

[msturtz]

kmb1966 wrote:

msturtz wrote:

kmb1966 wrote:
My 2001 Itasca Suncruiser has an Onan Marquis Gold 7000 generator. Started giving a code 37, brought in to the Onan service center. Service center says debris in the engine, bent rocker arm, burnt valves, some damage to excessive HEAT. Despite all of my religious oil changes, exercising, filter changes and only 750 hours, the unit will cost over 1900 to repair. Can't see spending that much money on that old of a unit. Also, I never understood why the unit came with a Marquis Gold 7000, when a 5500 appears able to do the job. My unit has basement A/C where the 20 amp circuit is tied directly to the 1st compressor (pulls about 12 amps) and the 30 amp circuit is tied to the EMS 30 amp system for the 2nd compressor and the rest of the unit. The Onan 5500 would appear to be able to handle this setup fine, and the Onan 7000 produces more power, but I don't see how I could utilize that extra power with the way it is wired. New Onan 5500 is around $4,000 and a new Onan 7000 is another $1,000
I suppose I am going to go with a new Onan 5500 with new warranty. Onan service center says it can solve the heat problem with a modification to the bin door with a louver/vent and a heat shield. Still trying to get details before I pull the trigger on this deal. Opinions welcome. Thank you in advance.

I would hazard a guess that you coach is wired for split phase 240 which is 120 per leg to neutral. We have a QD6000 that will not “start” both our 13,000 BTU ACs. The problem isn’t the running load it’s the start load. Starting two ACs even with a hard start capacitor is iffy with any generator less than 7k. Add to that it is very common for there to be other loads such as the converter refrigerator etc. if nothing else is on and I stagger the startup sometimes I can get both ACs running. Most of the time the generator overload protection system dumps all the loads. On one trip I forgot to turn off one AC and AGS started the generator and the first AC started but when the second one tried to start all the power went off from the generator. Bottom line is start loads will strain a generator even if it is able to start them.

Thank you for the feedback. My unit does not have 2 a/c units. It has basement a/c with 2 compressors. First compressor comes on and then if it cannot bring the temp down, the 2nd compressor comes on to assist.

Hmm... I have never heard of such a configuration. If I were to guess each compressor has its own condenser and evaporator by definition would function like two ACs would at least in current draw. The only difference would be the lack of an additional blower motor. A blower motor isn’t much of a draw compared to the compressor motor.

[kmb1966]

msturtz wrote:

kmb1966 wrote:
My 2001 Itasca Suncruiser has an Onan Marquis Gold 7000 generator. Started giving a code 37, brought in to the Onan service center. Service center says debris in the engine, bent rocker arm, burnt valves, some damage to excessive HEAT. Despite all of my religious oil changes, exercising, filter changes and only 750 hours, the unit will cost over 1900 to repair. Can't see spending that much money on that old of a unit. Also, I never understood why the unit came with a Marquis Gold 7000, when a 5500 appears able to do the job. My unit has basement A/C where the 20 amp circuit is tied directly to the 1st compressor (pulls about 12 amps) and the 30 amp circuit is tied to the EMS 30 amp system for the 2nd compressor and the rest of the unit. The Onan 5500 would appear to be able to handle this setup fine, and the Onan 7000 produces more power, but I don't see how I could utilize that extra power with the way it is wired. New Onan 5500 is around $4,000 and a new Onan 7000 is another $1,000
I suppose I am going to go with a new Onan 5500 with new warranty. Onan service center says it can solve the heat problem with a modification to the bin door with a louver/vent and a heat shield. Still trying to get details before I pull the trigger on this deal. Opinions welcome. Thank you in advance.

I would hazard a guess that you coach is wired for split phase 240 which is 120 per leg to neutral. We have a QD6000 that will not “start” both our 13,000 BTU ACs. The problem isn’t the running load it’s the start load. Starting two ACs even with a hard start capacitor is iffy with any generator less than 7k. Add to that it is very common for there to be other loads such as the converter refrigerator etc. if nothing else is on and I stagger the startup sometimes I can get both ACs running. Most of the time the generator overload protection system dumps all the loads. On one trip I forgot to turn off one AC and AGS started the generator and the first AC started but when the second one tried to start all the power went off from the generator. Bottom line is start loads will strain a generator even if it is able to start them.

Thank you for the feedback. My unit does not have 2 a/c units. It has basement a/c with 2 compressors. First compressor comes on and then if it cannot bring the temp down, the 2nd compressor comes on to assist.

[msturtz]

kmb1966 wrote:
My 2001 Itasca Suncruiser has an Onan Marquis Gold 7000 generator. Started giving a code 37, brought in to the Onan service center. Service center says debris in the engine, bent rocker arm, burnt valves, some damage to excessive HEAT. Despite all of my religious oil changes, exercising, filter changes and only 750 hours, the unit will cost over 1900 to repair. Can't see spending that much money on that old of a unit. Also, I never understood why the unit came with a Marquis Gold 7000, when a 5500 appears able to do the job. My unit has basement A/C where the 20 amp circuit is tied directly to the 1st compressor (pulls about 12 amps) and the 30 amp circuit is tied to the EMS 30 amp system for the 2nd compressor and the rest of the unit. The Onan 5500 would appear to be able to handle this setup fine, and the Onan 7000 produces more power, but I don't see how I could utilize that extra power with the way it is wired. New Onan 5500 is around $4,000 and a new Onan 7000 is another $1,000
I suppose I am going to go with a new Onan 5500 with new warranty. Onan service center says it can solve the heat problem with a modification to the bin door with a louver/vent and a heat shield. Still trying to get details before I pull the trigger on this deal. Opinions welcome. Thank you in advance.

I would hazard a guess that you coach is wired for split phase 240 which is 120 per leg to neutral. We have a QD6000 that will not “start” both our 13,000 BTU ACs. The problem isn’t the running load it’s the start load. Starting two ACs even with a hard start capacitor is iffy with any generator less than 7k. Add to that it is very common for there to be other loads such as the converter refrigerator etc. if nothing else is on and I stagger the startup sometimes I can get both ACs running. Most of the time the generator overload protection system dumps all the loads. On one trip I forgot to turn off one AC and AGS started the generator and the first AC started but when the second one tried to start all the power went off from the generator. Bottom line is start loads will strain a generator even if it is able to start them.