Need help GSO 480 oil issues

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nunook
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Need help GSO 480 oil issues

Post by nunook » Tue Dec 22, 2015 1:12 pm

Took the boat out the last two times oil pressure is 70psi to start, then as the motor gets hot the oil temp raises and the pressure drops to 40 running and 20 at idle. CHT staying at 350 degrees. My oil temp rapidly raises over 200 degrees on e it reaches 180.
The only thing I did was switch gauges wondering if they might be miss matched but appear fine at first. Switch from manual gauges. Had any one know if there is anything that would cause a oil volume restriction. I changed the oil and blew out the lines after the first run. Filter is new. Anyone have any answers
2006 Floral City 14' Deckover Lycoming GSO-480

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John Fenner
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Re: Need help GSO 480 oil issues

Post by John Fenner » Tue Dec 22, 2015 2:45 pm

One or two things happening here, the return port in sump is causing the oil to get aerated or the ring lands are tired in the pistons and the oil is getting heated by blowby.
I never finish anyth,,,.

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nunook
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Re: Need help GSO 480 oil issues

Post by nunook » Tue Dec 22, 2015 4:34 pm

Kinda odd never have had an issue with the oil temp going over 180. this all occurred out of the blue with no warning after switching to electronic gauges, is it possible an oil ring might have broke causing the oil to heat? If it was blow by I couldn't see it heating the oil (16 qt) as fast as it does either, once it reaches 180 you can watch it move while running about 2400 rpm's It appears oil is not circulating thru the cooler in any volume to cool the oil causing the oil to heat and thin out. The oil lines to the cooler are hot to include both the feed and return line. Other then that the boats runs like great no power lose. Any suggestions how to check. I was going to remove the return line going to the sump tank and put in a bucket and start the engine verify it is pumping oil good.
2006 Floral City 14' Deckover Lycoming GSO-480

AirHog
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Re: Need help GSO 480 oil issues

Post by AirHog » Tue Dec 22, 2015 4:59 pm

Do you have an I infared gun to cross check the gauge?

They are not that much money. I keep one in my boat bag.

Shoot the heads and the oil pan .....on my a/c (520) the heads stay below 400 degrees
Unless I am flogging it...... 500 and its game over. Oil temp is usually 200 or below
But that's mine.... Other 480 owners may have a snapshot for you

Good luck
AirHog
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nunook
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Re: Need help GSO 480 oil issues

Post by nunook » Tue Dec 22, 2015 5:50 pm

The funny thing is the CHT temperature is consistent 350-378 degrees never even reaching 400 degree's I do have a IR gun and forgot to bring it today. I'm leaning toward maybe a oil circulation issue or possible a ground / gauge issue. If it is an oil circulation issue not exactly sure where to look. I will try to duplicate the issue here at home then switch the gauges to a manual one to see if they match.
If I was getting blow by I venture to say my breather would be putting out a lot of smoke if the temp is rising as quick as it was on the gauge
2006 Floral City 14' Deckover Lycoming GSO-480

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nunook
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Re: Need help GSO 480 oil issues

Post by nunook » Wed Dec 23, 2015 8:50 pm

After speaking with a few people I'm going to check the oil pressure after going they the motor. Leaning toward a bad rod bearing thanks Gary and Bill
2006 Floral City 14' Deckover Lycoming GSO-480

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nunook
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Re: Need help GSO 480 oil issues

Post by nunook » Thu Dec 24, 2015 8:03 pm

Good news does not appear to be a Main Bearing or Rod bearing. I placed a oil pressure gauge on the back of the engine and received the same read as at the pump, as the pump pressure decrease so did the rear pressure which matched. Based on that I figure there is a bad bearing in the Gear Box on the front of the motor, guessing it will be the intermediate supercharger bushing being I have had an issue in the past. With any luck might be able to get it pulled this week.
2006 Floral City 14' Deckover Lycoming GSO-480

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nunook
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Re: Need help GSO 480 oil issues

Post by nunook » Sun Jun 25, 2017 6:44 pm

I never updated the post, it turns out I had three bad oil injectors in the cylinders free flowing oil off the main oil journal, ended up replacing bearings while I had it apart but they didn't seem bad.
It appeared once the oil thinned it wouldn't open the bypass to the cooler thinning out the oil and heating it rapidly. Thanks for all the input.
2006 Floral City 14' Deckover Lycoming GSO-480

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