Engine coolant temperature 199-203 but high engine oil temperature of 243

2009 FORD F-350
230,000 MILES • 6.4L • V8 • TURBO • 4WD
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JIMMYHARTLEY
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I have a 2009 6.4 power stroke, with engine oil temp issues . Had a leaking oil cooler that went into coolant system . Flushed system good. Changed oil cooler , flushed again with Prestones flush/degreaser and temperature slowly climbs up to 243 but coolant stays at 199-203. I’ve re-flushed it four times. Both temperatures are right together at startup until coolant reaches its 199 mark, but oil keeps slowly climbing. Any ideas?
Dec 19, 2018 at 3:00 PM
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ASEMASTER6371
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Good afternoon,

Are you using the correct weight oil? That is critical.

I would also use full synthetic oil as well.

Fluid Types


Engine Oil .................... Preferred Motorcraft Motor Oil 15W-40 Super Duty

Ford P/N .................... XO-15W40-QSD

Engine Oil .................... Motorcraft Motor Oil 10W-30 Super Duty

Ford P/N .................... XO10W30-QSD

Ford Specification .................... WSS-M2C171-E
Capacities


Engine Oil .................... 15.0 quarts (14.2 Liters)

NOTE: Includes 1 quart (1.0L) in oil filter.

Roy
Dec 20, 2018 at 9:46 AM
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JIMMYHARTLEY
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Not sure . I would assume. The shop changed it. That would make a big difference to bring the temperature down?
Dec 20, 2018 at 9:48 AM
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ASEMASTER6371
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yes, the type and viscosity are critical to oil temperatures. a lot of shops do not know or care about it. they just put in any oil they have to maximize their profits.

Roy
Dec 20, 2018 at 10:05 AM
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JIMMYHARTLEY
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But wouldn’t my coolant temperature be up as well? It’s reading 199 and engine oil temperature is 243.
Dec 20, 2018 at 11:16 AM
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ASEMASTER6371
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no, the coolant is controlled by the thermostat and the radiator.

Roy
Dec 20, 2018 at 12:24 PM
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JIMMYHARTLEY
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Thanks Roy.
Dec 20, 2018 at 3:05 PM
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ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
Dec 20, 2018 at 9:46 PM