How High for Synthetic?

[sjl2725]

I run Mobil 1 Turbo Diesel 5w-40 (full syn). How hot can it get before it compromises the oil?

Here is the long version, again-
Delta temp 2-3 degrees when I first installed the DashDaq 2 years ago
delta temp around 20deg, oil cooler replaced 8k miles ago at dealer
deltas after change were about 8-10
deltas gradually 20-30, 40-50 with 5th wheel (4 weeks ago)
flush with RESTORE and RESTORE PLUS,
change thermostats for good measure
temps 192-202ish, but spiked up to 215 once for no reason. Heat seems to take a while to get hot, but when it does its all at once.
filter kit arrived today...
probably asking dealer to order a new oil cooler tomorrow, will return to stock over the weekend to get the wrench light.

However, we have a camping trip planned next weekend. Truck might not be fixed. Just put 130 dollars worth of oil in it and don't want to ruin it.

Anyone think I have a bubble?

PS, I have about had it with this situation.

[superduty6.4]

I am pretty sure I read one time that at 250 f is when the properties start to be compromised. I have seen as high as 230 on mine a couple summer ago but it hasn't hit that high since that one time.

[04hdfatboy]

So what are your delta's currently? Did the flush help your deltas? If the temp difference is 40-50 degrees i would not be using the truck until its fixed. Maybe you should look at that additional oil cooler from BPD.

[sjl2725]

right now, it is USUALLY running 192-194 and 202 to 204... 10 degrees should give me a P012F code, but tuner is hiding it...

So yes, the flush and CAT ELC seemed to help. There is still that 8-10 degree spread but the EOT isn't 220 anymore, HOWEVER, last night driving mildly on secondary road all of the sudden it was 215 and went to 220. I THINK I might have an air pocket in there because my damn heat doesn't work right. Even at operating temp, its cold, then all of the sudden blasts me with hot air. If there was an air lock in the cooler lines, you would think that might cause an issue. Yes?

Im about to go on a parts run, and going to stop by the ford dealership and talk to the diesel tech.

I might try to jimmy rig the vacuum pump to the degas bottle and refill through the rad drain. I know sounds weird, but.....

If I have to cancel this trip next week, the wife is going to be livid!

[04hdfatboy]

get up to operating temp and carefully take the cap off the degas bottle. If you have high idle leave the high idle on and squeeze the upper radiator hose. That is how i got the air out of mine after the flush. Your deltas arent too bad at 10* as i believe it wont throw a code until 15+ degrees. Either way your deltas shouldnt be that high.