5500 generator keeps shutting down after break in oil change

I had it happen when trying to use 10-40 oil. Changed to 30 wt. and it is no longer an issue. Evidently cavitation was causing a low pressure reading.

Owners manual calls for 15-40 or 30

Also, here's a quote from the manual,

Oil Filters
Green Label Parts oil filters feature valves that allow oil to bypass the oil filter
during cold starts, or if the filter becomes plugged. Other manufacturers’ oil filters
often do not have bypass valves. As these “will-fit” filters trap debris, oil pressure
starvation can occur, leading to high oil pressures, failed gaskets and even engine
damage. Other “will-fit” oil filters may contain a bypass valve, but it’s not possible
to determine at what PSI the valve opens. If the setting is too high, the filter’s paper
element can be damaged during a cold start rendering it useless, or cause oil
starvation to the engine.

Thanks. Yea, caught that I used the wrong oil. Going to change it again today and see if that does the trick.

bman. Make sure you use an ONAN oil filter. Or Generac, if you have a Generac. Onan is real strict on the filters. Go back and read Dakota's post. He is right on the money. We get this many times every month at the shop. Wrong oil/wrong filter.

I did use the Onan filter

Just did a new new oil change wirh the right oil..... Yep, works fine now....

This is good information to know. I would not have thought that the oil viscosity would make that much of a difference.

Thanks for the info!

strange, have used 10/40 in mine since first oil change, never an issue. Onan Marquis gold 5500

nayther wrote:
strange, have used 10/40 in mine since first oil change, never an issue. Onan Marquis gold 5500

Same here...