We're in the ARI service bay now with the generator out of the truck and the panels removed. It has been in the truck for six years and has provided 11,500 hours of nearly trouble-free service (fuel pump warranty replace in first weeks after install, belt replacement done myself, exhaust flex pipe replaced in year six). But after six years, it is proving to be very wise to reward our generator's faithful service by giving it a trip to the day spa, so to speak.
Unlike most generators that are seen on trucks, Onan generators are made for big RV's and are tightly packed together. The only way to see some of the components is to remove the generator from the truck and open it up as we are doing today.
Findings:
1. The generator got dirty (no surprise). Especially significant was the dirt that built up in the radiator fins. We had no cooling system issues but eventually would have if the radiator fins had not been cleaned.
2. The molded hose that runs from the water pump to the radiator was not leaking but had grown soft in one place. It would have burst at some point in the future so we replaced it.
3. The other cooling system hoses were fine. No action taken.
4. The increased noise (mentioned above) was due to a cracked air box (my term). There is an air intake hose that leads from the air filter to a plastic box. The box connects to the intake manifold. Technicians said heat, vibration and age degrade the structural integrity of the plastic, which explains our cracks. Some non-filtered air would have been drawn in through the cracks. Probably not a serious problem because we rarely run the generator when driving, and when we do, it's only for short periods. No dust when we run the generator while parked. Even with the cracks, the majority of the intake air would still be filtered. Box will be replaced. It is not in stock but ordered for delivery tomorrow. Improvement in engine breathing may be noticed but no performance issues had been noticed before, other than a slight increase in engine noise.
5. One motor mount replaced. It was still intact but the rubber was softer than that of a new mount. Got that way, probably, from oil spilled on it during oil changes that soaked in over time.
6. Engine coolant was found in the water pump weep hole. We had no issues with coolant loss or overheating but, clearly, the water pump was on its way out. Replaced.
7. Power output terminals were corroded. No issues related to that. Like battery terminals, they need to be cleaned every now and then.
8. The starting issue remains undiagnosed. They are cleaning up the generator and making obvious repairs first. One electrical connection is corroded but we do not know if that was the problem. Continuity checks will be made later.
While it would have been nice to not deadhead as far as we did to get here, we are delighted, as usual, with the attention to detail and care ARI technicians are giving. If the above issues were not resolved with a day-spa trip like this now, they would have resulted in generator failure and more down time later.
We will leave here very confident in this piece of equipment and expect thousands more hours of trouble-free service out of it. Onan generators with over 25,000 hours on them are commonly seen here. They have seen one with over 40,000 hours on it. They consider our 11,500 hours in six years to be light use.
