In theory 5W-40 oil isn’t higher viscosity than either 5W-20 or 30. In theory it just loses viscosity slower as the temp increases, and our engines it seems run HOT, especially the heads due to the exhaust manifold being part of the head.
The greater the difference in the two numbers, the faster the oil breaks down because the viscosity improver additive is among the first additive to break down.
In truth I believe 5W-40 is higher viscosity than 5W-20 even at room temp, theory be damned.
If I were to go to 5W-40 it would be Shell Rotella, yes I know it’s Diesel oil, but it’s also very good in spark ignition engines. Good Diesel oil has better thermal stability etc than spark ignition oil.

I think though if you live where it gets real cold in Winter I’d probably run 5W-20 then myself.

 

I use Rotella T in my older 911. Works well. I am in FL where it almost always warm. I am lucky to see a couple days in Early January to see 30's.

As an update, I haven't been able to get out and check the wiring. Weather down here has been miserable with a lot of rain.

Did some driving of the Jeep to grab dinner one night and the CEL went off for a while on starting. The next morning it came back on and a short drive produced the traction control light and limp mode. Stopped and restarted the engine and the traction control disappeared but the CEL was still illuminated. 2 days later the CEL turned off again. Been driving it for 2 days and no CEL, but saved codes for the Intermittent Signal and the Torque denied.

There is no limp mode activated and it is driving normally.

Pretty weird. I don't know if I will get to check the wiring out this weekend, every forecast I see says more rain.

Since they are both saved I am going to wait to clear them and see what happens.

 

I live in Weirsdale Fl, I have an aircraft hangar that you could use if you want to troubleshoot, it has a 2 ton mini-split that keeps humidity below 65% and temp rarely gets above 82F or so.
I hesitate to say it’s Airconditioned, but it’s actually pretty close. The intent of the mini-split is to dehumidify and prevent corrosion.
I’m Retired so anytime would be fine. I think we are about 60 miles apart, little over an hour drive.

 

Thanks for the offer, I may take you up on it.

I am over in Ormond Beach, so not far at all.

Let me know if you are ever over in the area.

 

No problem, I’m Retired so anytime.
I’m new to the forum but I am going to try to PM you my phone number, I assume there is a PM function, sometimes though you have to reach some number of posts though before you can PM, it’s to keep the bots out.