When I put full load on gen it cuts off and throws a 33 code. I checked coolant and air filter as per manual both ok . What could be the problem?
Sam, I had the back air, microwave and coffee pot turned on and it ran about ten mins. It has around 600hrs on the gen.
Thanks everyone for the help
Thanks everyone for the help
Well,
Yeah, you could say I "had" a handle on it. My 7.5QD had the same code back a while ago. Super long story short, I had to replace that coolant temp sensor. Lucky for me, the gen is on a slide out tray. That makes for seriously easier maintenance and repairs to be done. But, that sensor can be a real bear to get out or, it could simply unscrew, just like a spark plug which, it's about the same size as.
Just for info here, the cooling air is drawn in from underneath, in the center front. It's first job is to cool the major electronics that are mounted right up front. Then, it cools the rotor and stator. From there, it turns sideways, and cools the radiator.
From there, it's ducted through what's called the center bulkhead and into the area where it finally cools the exhaust and muffler.
It is then jettisoned out the bottom, towards the rear.
That sensor, if it's your problem, is located in a spot that you can easily see but, not actually get a great bite from a socket or a wrench. I have a whole series of pictures of my generator almost completely torn down, for replacement of that sensor and, the rotor which, had one of its magnets disintegrate and send magnetic shrapnel all over the inside. What a mess.
But, once that sensor was replaced, it's been acting fine.
Scott
Yeah, you could say I "had" a handle on it. My 7.5QD had the same code back a while ago. Super long story short, I had to replace that coolant temp sensor. Lucky for me, the gen is on a slide out tray. That makes for seriously easier maintenance and repairs to be done. But, that sensor can be a real bear to get out or, it could simply unscrew, just like a spark plug which, it's about the same size as.
Just for info here, the cooling air is drawn in from underneath, in the center front. It's first job is to cool the major electronics that are mounted right up front. Then, it cools the rotor and stator. From there, it turns sideways, and cools the radiator.
From there, it's ducted through what's called the center bulkhead and into the area where it finally cools the exhaust and muffler.
It is then jettisoned out the bottom, towards the rear.
That sensor, if it's your problem, is located in a spot that you can easily see but, not actually get a great bite from a socket or a wrench. I have a whole series of pictures of my generator almost completely torn down, for replacement of that sensor and, the rotor which, had one of its magnets disintegrate and send magnetic shrapnel all over the inside. What a mess.
But, once that sensor was replaced, it's been acting fine.
Scott
golfman 1 wrote:
When I put full load on gen it cuts off and throws a 33 code. I checked coolant and air filter as per manual both ok . What could be the problem?
golfman,
Code 33 on many of the 7.5QD Onans is what's labeled an "Overheat" condition. And, in the service and owners manuals, they list possible causes. About 99.99% of which, never are the cause.
1. Plugged cooling air intake
2. Plugged cooling air exhaust
3. Damaged cooling fan
And a few more.
A very large percentage of the time, the actual cause is the "Temp sensor". It's a sensor, located in the lower half of the thermostat housing, in the back (or front, depending on how you look at things) of the engine. Long story short, that sensor can get severely corroded, inside it's pocket in the housing and, cease to send correct signals to the little Kubotas ECM. When that happens, it sends false heating info to that ECM and, the ECM then shuts the engine down, even though it's running at the appropriate temp.
I'm not guaranteeing that this is your issue but, about 80% of the time, it turns out to be it.
Scott
