I discovered a chewed up impeller after checking on lack of water in the exhaust and slight overheating. It still starts and runs. Is there anything I should check or change out, besides the impeller, to be sure there is no damage from the overheating?
M18 overheat
- Thread starter reeder
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When you pull out the impeller, collect all of the pieces. Make sure that you have all the parts. If you are missing any, you need to find them. In particular, look into inlet and the outlet of the pump. Use a stiff piece of wire with a hook on the end to reach into the inlet and outlet to retrieve any missing parts.
I have seen a broken impeller piece get lodged into the intake of the pump and then damage a new impeller when it come loose.
In my experience, if you are missing only a few very small pieces, they are probably down-stream from the pump and are in the heat exchanger. If it is easy to open the HX, do so and clean out the impeller pieces. I personally have a HX that is very difficult to reach on my generator and I have left a few small pieces stay in there with no ill effects. YMMV.
I have seen a broken impeller piece get lodged into the intake of the pump and then damage a new impeller when it come loose.
In my experience, if you are missing only a few very small pieces, they are probably down-stream from the pump and are in the heat exchanger. If it is easy to open the HX, do so and clean out the impeller pieces. I personally have a HX that is very difficult to reach on my generator and I have left a few small pieces stay in there with no ill effects. YMMV.
These engines can withstand mild overheating. As a matter of fact the warning buzzer will go off well before reaching critical temperatures. I would say just observe the engine for any abnormal behavior but as far doing something you may change the oil. High temperatures will degrade the viscocity of the oil. What Rich says about making sure you get all the impeller pieces is religion, he is not just being picky. Left over pieces will likely show up in the future by clogging cooling passages and causing overheating maladies.
In addition to the good advice by Rich and Benny, I think you need to find out the cause of the "chewed up impeller" so that it doesn't happen again. In some cases, sucking up gritty mud or sand while backing off from a soft grounding can cause the death of an impeller. More important is that you ensure that the interior of your raw water pump has not been damaged as well. Any imperfection in the interior surfaces of the pump, the cam, or the cover will destroy a new impeller quickly.
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