I know this question has been asked before but I can't find the answer. Last year while towing my fifth wheel to the North Rim of the Grand Canyon my oil temp went to 260 degrees several times. The outside temps were 95 degrees at the start and it is a long steep climb with a heavy load. Each time I pulled over for a bit, as I couldn't remember at what temp that plastic thing inside the oil filter melted. Each time it cooled off fairly quickly but it really stressed me out. So how hot can the oil get. I am using Rotella T-6 and my temp different is only 12-15 unloaded. Could I allow 280 for 15 minutes or so? Thanks for your help. This time I will write the answer down.

 

Here is a great link to a thread in the Tech Folder that lists temp readings

https://www.ford-trucks.com/forums/9...-pressure.html


.....for the EOT - Engine begins to defuel at 253 *F oil temp per the PC/ED manual.

So , 260 would be high and 280 is not good. Have you ever had the oil cooler replaced or perhaps consider one of the BulletProof external oil coolers?

How much weight are you towing?

 

Sorry but if I'm hitting 240+ I'm backing off. Pulling 8% grade @ 21,000lbs. GCVW it may be around 226-230°f depending on how many miles it is at 90° ambient.
280 degrees? Forget it.
OP, what are your coolant Temps when your oil was 260-280? You may have a clogged oil cooler or the bypass is stuck open bypassing the cooler. What's your GCVW?

 

Yikes, I would definitely be worried at those temps! I would be backing off before hitting fuel cutoff at 253, probably 240.

Worst I've ever seen pulling a long grade is around 235 with a ECT of 220-225. Temp spread is 7-10F unloaded on the hwy.

 

Looks like you and I are on the same page.
If I ever saw Temps like he is seeing I'd have to pull over anyways to throw up.

 

I should have asked about your fan, do you hear the fan kick into high gear at 220+ temps?

What are you using to monitor your temps?

 

The oil cooler was replaced about 45,000 miles ago. This is the worst climb I have done. High outside temps, 17,600 pound total load (truck and trailer), and 8 percent grade in some parts. I believe it is about 9000 feet at the end. It is also a long climb of over an hour. I will just pull over a little more if I do this one again.

 

Forgot to mention I have the scan gauge and mechanical gauges and the fan ran great.

 

Just out of curiosity Randy777,

Do you see a difference in oil temps between the Scan Gauge II reaading and the Isspro Oil temps (as well as the coolant temps)? I see about a 10 degree difference in oil temps on my 7.3L between my ISSPRO gauge & OBD II reader. The sensors are in different locations on my setup. Don't mean to compare apples to oranges, just curious if you have a separate oil temp sensor for the ISSPRO gauge.

 

Sorry about the slow reply White Buffalo but as to your question. Yes I have quite a difference between my Scan Gauge reading and my Isspro gauge reading. When cold my Isspro sensor which is in the side of my oil pan reads about 2 degrees high (pretty close). But when towing with a heavy load in a climb the Isspro reads up to 15 degrees higher. I assume this means the oil in the pan is hotter due to cooling the hot piston sides? Or maybe the oil at the scan gauge sensor has been cooled by the oil cooler??? The water temp sensors don't seem to have that much of a difference hot or cold.

 

I'm not sure on the reason for the difference on the 6.0L. But I experienced the same on my 7.3L. My oil temps read about 10 degrees different from the sensor on top of the engine to the ISSPRO sending unit by the oil filter. Just a different location in the oil path. Noticed the same thing on the trans temp sensor in the test port compared to the internal OEM trans temp sensor as well.

Which means:

If your ISSPRO gauge is reading 260, the OEM sensor that the scan gauge is reading is approx 245. So not as high of a temp as you thought - still high and needs to be addressed, just not as bad as 260.

 

Oil gets picked up by the LP pump and pumped thru the oil cooler & filter then to the motor. It then absorbs heat from the motor, turbo, HPOP, etc and then drains back to the pan. Hottest oil will be in the pan. The factory sensor is downstream of the oil cooler, hence the lower temp than what you're seeing in the pan.