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Topic: Onan QD 8000 High water temp fix. (Read 968 times) previous topic - next topic
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Onan QD 8000 High water temp fix.

Yahoo Message Number: 91237
I finally found a fix for our high water temperature issue with our Onan QD 8000 generator.
If we ran both roof AC units the generator would quit after about 30 minutes. We would get a secondary blink code of 33 indicating high water temperature. After doing all of the checks listed in the troubleshooting guide I drained the coolant and flushed the system with water. The water came out as clean as it went in. I added fresh long life coolant and still had code 33s. I purchased a product called Fleetguard Restore Plus after reading about someone having good success with the product. This is a mild acid based cooling system flush. I followed the instructions and after running the generator for about 45 minutes with the solution in the system I drained it out. It looked like I was draining the black tank. I could not believe what came out of a seeming otherwise clean cooling system.
After another flush and rinse I filled the generator with fresh long life antifreeze and now the generator can handle a full load.
I purchased the Fleetguard Restore Plus at Cummins Northwest for $32.95 a gallon. I only used about a pint. Our generator is an 04 unit and it only had around 130 hours on it when we purchased the Coach a couple of years ago. I have the service records and the previous owner always had the generator serviced regularly. My guess is it still had the original coolant.
 

Re: Onan QD 8000 High water temp fix.

Reply #1 –
Yahoo Message Number: 91269
The Restore+ is a great product. When I did a coolant flush on my 2006 Ford 6.0, I used 1/2 gallon Restore with distilled water to remove the silicate build up turns it into a clear honey ran it for an hour did 5 flushes with distilled water then used 1/2 gallon Restore+ then ran for another hour to remove the mineral buildup did 5 more flushes with distilled water checked with ph strips to get a 7.0 then add 3 1/2 gallons Delo concentrate coolant Cat EC-1 Rated ELC coolant only took me 12.5hrs and 54 gallons of distilled water but the system is clean. My C9 Cat has a new radiator Brass and Steel and Quinn Cat did a flush on it before the install. In the spring I will be looking at doing the genset also so it will be another trip to Cummins to get some restore product because I sold my other 2 jugs of restore. My genset has about 500hrs on it.
Floyd 2006 Inspire 51744.