I have a 2005 Excursion with the 6.0 PSD and 87,000 miles.

12,000 miles ago I had the oil cooler and EGR replaced, coolant filter installed and a complete flush. Maintenance is always done on time.

Lately, while doing both city and highway driving, I have noticed that my oil temp will actually fluctuate a lot and be LOWER than my coolant temp. My coolant temp stays pretty even at 190 degrees +/- a few degrees.

The oil temp is always lower than the coolant temp (by 8-15 degrees) at start up and for the first 10-15 miles. They then level out and will run even or within 3-5 degrees. Frequently the oil temp will drop lower than the coolant temp by 5-20 degrees while doing city and highway driving. Yes - my oil is cooling my coolant!!

My coolant is always well within spec - I do not have an overheating issue.

I have seen these combinations on my Edge:

Coolant at 190, Oil at 190-195
Coolant at 190, Oil at 180
Coolant at 190, Oil at 183
Coolant at 195, Oil at 185
You get the idea.

Oil pump problems? I also heard there is an oil "line" than runs through the center of the engine and when it gets plugged it may cause this to happen.

I don't know whether to be concerned or not.

Thanks for your advice and thoughts.

 

IDK about the oil line ceter of engine

But by design you have a problem if ECT higher than EOT

maybe a bad sensor ECT or EOT

Maybe a BAd Gauge

maybe a water pump/front cover issue

What do you get for ECT and EOT after 12 hour cold soak?????? they should be the same

Id start with the sensors

 

When I first start up from cold in the morning the temps are always right in line - within a few degrees and generally the ECT is colder than the EOT. Nothing seems weird at this point.

But a block down the road after a cold start and the ECT is higher than the EOT.

Appreciate your thoughts.

MC

 

The temperature doifference doesn't mean anything until you have driven 10-15 miles and gotten everything heat saturated. If, after things are all hot, you see dips in the oil temp, then I would look at the sensor and/or wiring as Benny said.

 

They should be the same temp after 12 hours cold soak close to ambeint temp

That goes for ALL fluid temps too like ECT & EOT & TFT






This is normal^^^^^^

as the truck heats up ECT will lead the way EOT will chase COOLANT TEMP (10-15* behind) till it gets to a ECT of 190* or close actuly when the thermostat opens at this point is when EOT should Pass ECT

Looking at the temps you posted only the first one look like it was fulley warmed up (the ECT 190* & EOT 190-195*) the rest didnt look like it was fulley warmed up but if it was fulley warmed up when you took other temps then you have an issue

 

I posted on this back in December. Coming back from Az. my eot went 7 to 8 degrees cooler than the ect while on the hiway, 400 mile trip. Took it to ford, they ran all the usual tests and said that the spread was in normal specs. The ect/eot are the same when cold. I personally think the eot sensor is going flakey but since the truck is still under full warranty and Ford is OK with it, then I'll live with it knowing the new parameters. If it wasn't under warranty I'd change out the eot sensor. It was Ford in Detroit that said the temps were in normal specs. The dealer tech agrees with me but without PaPa Fords blessing can't replace the sensor.