Onan 9KW Diesel genny - error code 58

[First_Mate]

My Onan 9 MDKAV shut down this weekend due to a bad impeller. I replaced it with a spare and the first time I started back up, it immediately shut down with error code 58 - High Exhaust Temperature.

Started the second time and ran fine for about three hours. Then today, I tried to start it and it shut down after three seconds with error code 58. Tried this again about ten times and it finally stayed running for about 5-8 minutes before shutting down again with another 58. Now I can't get it to stay running...

During the 5-8 minutes, the water flow was good and things appeared normal. There was no load on the generator.

I haven't tried to remove the vanes from the old impeller yet. (Not sure exactly how to do this) Could this be the problem?

 

[GMAN1]

Need to remove vanes from system. Start at impeller housing and follow the water hose all the way down to the heat exchanger. Open up the end cap and I bet you will find your problem there. Anytime impellers go bad and have missing vanes you need to extract them or you will be replacing another impeller soon.

 

[First_Mate]

Chased down the vanes and removed them. Still same error code.

Went back to the exhaust temp switch and removed/reconnected the leads. Started right up and ran 3.5 hours under load. Hope that was the problem. Ordered a spare exh temp switch just in case...