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Oil temp higher when idling vs. running?

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Old 07-23-2007 | 11:03 AM
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Default Oil temp higher when idling vs. running?

Sorry for the newbie question, but is it normal for the oil temp to rise rapidly to the 220-240 range when you come down to a idle or low speed condition?

If I start running at a decent speed 30+mph, the oil temps will drop down to ~195 with 2-3 minutes. When I come to an idle situation, it climbs back to 220-240 with 1 minute. This occurs consistently.

Oh and this is regarding the 525EFI motors.

Normal?

Thanks.
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Old 07-23-2007 | 11:52 AM
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Seems way too high at all rpm's....looks like you have a blockage somewhere.
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Old 07-23-2007 | 12:20 PM
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NORMAL

has to do with the water flow, thermostats, etc..
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Old 07-23-2007 | 12:20 PM
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Check your sea water pump impeller...you may have busted a few blaeds off it...and the combo of less blades and possible the busted ones blocking flow of water at idle may be enough to raise temps.....
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Old 07-23-2007 | 01:11 PM
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I will check the sea water pump. Thanks for the information.

Additionally, the oil pressures seem normal at ~30-40psi idle and ~50psi off idle. The Water Pressure gauges show ample pressure when running as well. At 50mph, they will be around 25-30psi water pressure.

Last edited by Viper TT; 07-23-2007 at 01:16 PM.
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Old 07-23-2007 | 10:35 PM
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Originally Posted by Wally
Check your sea water pump impeller...you may have busted a few blaeds off it...and the combo of less blades and possible the busted ones blocking flow of water at idle may be enough to raise temps.....
I would start there.
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Old 07-23-2007 | 10:50 PM
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It's a brand new boat he shouldn't have a problem with the impeller. And the engine temp, water,oil psi is normal. Could be just in the guage. Both motors are doing the same?When I have Diacom hooked up and comparing the actual temps and pressure that the computer reads compared to the guages there is a noticable difference. Keep enjoying your new boat. Smart Craft will let you know when you have a problem.
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Old 07-23-2007 | 11:01 PM
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Ideally oil temp should be 220 240. Oil isn't too hot until it exceeds 270 275. You need oil temp at least 220 to keep condensation out off the motor. 195 is result of good water flow and little load on motor. The new big motors from Merc, Sterling and others have thermostats in the oil system to keep the oil temp up.
Jim
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Old 07-24-2007 | 08:01 AM
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Originally Posted by turnerrd
It's a brand new boat he shouldn't have a problem with the impeller. And the engine temp, water,oil psi is normal. Could be just in the guage. Both motors are doing the same?When I have Diacom hooked up and comparing the actual temps and pressure that the computer reads compared to the guages there is a noticable difference. Keep enjoying your new boat. Smart Craft will let you know when you have a problem.
Thank you! Yes, both engines show similar results. Everything else shows normal. I hit 25 hours over the weekend. I finished changing all the fluids last night along with the fuel filters.

I purchased the Rinda Mercruiser handheld scanner and the fault history shows everything as happy. The only Fault Second readings that show up is "Overspeed," which I assume is bumping the rev limiter when the boat comes off a wave. All the other codes show zero seconds.

Last edited by Viper TT; 07-24-2007 at 09:47 AM.
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Old 07-24-2007 | 08:02 AM
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Originally Posted by MOBILEMERCMAN
Ideally oil temp should be 220 240. Oil isn't too hot until it exceeds 270 275. You need oil temp at least 220 to keep condensation out off the motor. 195 is result of good water flow and little load on motor. The new big motors from Merc, Sterling and others have thermostats in the oil system to keep the oil temp up.
Jim
Good information. Thanks.
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