I recently changed my oil cooler due to the oil in my degas bottle. Before I changed the cooler my ECT was 188-190 and my EOT was 196-198 @ roughly 60-65 degree outside temp. runnig 65-70 mph. These temps were the norm while driving for approx. 30-45 min (after warm up). My current temps are ECT 184-190 / EOT 198-202 under the same driving conditions. When I done the cooler change, I took the week off from work and went really slow to make sure I done everything right. While I was at it I changed the intake manifold gasket, turbo hardware, installed updated turbo oil drain, cleaned the intake and everything else, installed new thermostat(192*), degas bottle and coolant bypass filter. Since this is already a long post. Yes, I did backflush then regular flushed w/Restore numerous times and then done it all again when the new cooler was installed. I ran the truck pretty hard today on the interstate approx. 500 miles after all of this maint. was done and my ECT reached 200 and my EOT was about 220. When I settled down to interstate speed. My ECT stabilized at 190 but, my EOT stayed around 208 until I got off the interstate. I have brand new ECT & EOT sensors that I just picked up (everything else is new, why not these also!) I guess my question is, should I be concerned or wait til after I change the sensor and then see. I have 195K on a 03 6.0 and Im running Fleetgaurd w/distilled water. Sorry for the long post and thanks in advance.

 

SD daddy the last flush you did with the new cooler in might have got some stuff in your new cooler . personally i would not have done the last flush . But what the hell i have a year and a half old cooler that i put in and see 8 to 12 diff and don't worry to much .

 

When you say you settled down on the interstate, how fast were you driving and with or without a trailer?

I've seen several guys on here that are seeing a 8-10 degree delta all the time; even after an oil cooler replacement. Not really sure why they're that high, you'd think they'd be down around 2-3 degrees since these are assembly line built engines. The only other thing I would suggest, maybe a VC9 flush, then back flush the engine. At that point, if the delta stays where it is...that's a character of the truck.

 

I was running about 95mph after getting out of some slow crappy afternoon traffic and dropped the hammer when getting on the interstate (about 1/2 mile at that speed). The truck said it was 79* outside. Didn't mention it earlier but, I drained coolant from lower radiator hose and from the Fumoto valves I installed on each side of the block when I done my maint. Truck normally runs about 5* hotter on both temps when Im in that slow moving traffic.

 

So basicaly you had a 18* spread on a New Oil Cooler

Might as well put the new temp sensors in see if that helps

Also are ECT and EOT the same after 12hour cold soak even check TFT for Kicks

If the new sensors dont help I am thinking the same as David might have plugged the new Oil Cooler or The Water Pump and front cover need to be removed and Cleaned out

How Bad was the Cooling system Contaminated with oil if really bad its like a Paste and the WP dont Pump Paste very good so might need a Good Cleaning

 

My TFT stays 150-152. My deltas stay at 8-11* under my normal driving conditions. Its just that before the cooler change my spread was 6-8*. My ECT/EOT are exactly the same after a cold soak approx. 7-8 hrs. I appreciate the advice. Will change sensors and see what that does. Once again thanks.

 

Interesting. I still have a 27* spread after sitting overnight.

 

Keep the one closest to ambient and replace the other.

 

Tried that, no difference.

 

What gauge do you hasve????????

If its a SGII reset to manufacture settings and then check those x codes

 

Well after 12 hour cold soak we assume all fluids are the same temp

Does either EOT or ECT gauges report erratic like in all over the place this would be a sign of a bad sensor

 

I use an OTC with the latest up grades. My other 6.0's all have 3-6* difference. Replaced the oil temp sensor with a new one, no change.

 

what do you think caused the old oil cooler to fail and leak oil into the coolant if the deltas were good prior? I would try the sensors also myself, some have seen the deltas magically come down after swapping them for new sensors.
posts like these make me glad i got rid of my stock oil cooler.

 

I don't see EGR cooler in the parts list, so I assume you didn't change it, because it is an '03 with the indestructible round cooler. Did you happen to check it for free flow?

If either cooler is restricted, flow through both is restricted. So it would seem that either your oil cooler plugged again, which unfortunately happens all too often, or your EGR cooler is plugged.

 

You said you replaced the thermostat..... it's VERY possible that it's just the nature of a different stat..... I wouldn't sweat it.....