**see page 5 for updates after installing an OEM cooler**
I bulletproofed my '06 last fall. Studs, EGR delete, new Sinister oil cooler, 4" cat back, Livewire with ID tunes, blue springs, thermostat, etc. I noticed immediately that my ECT-EOT deltas were kinda high 190 vs 206 (16 degree avg) at 65 mph. So I flushed the system with Restore and Restore plus and changed to using ZEREX ELC diesel coolant and installed a coolant filter. Still no change. Sinister and I had been exchanging ideas about the issue, and when my EOT went to 235 coming up afton mtn, they decided to sent my a new (Sinister) cooler.
Installed the new cooler last night and was excited to drive it and see my deltas fall back to WNL. Didn't happen, my temps did not change. Delta still hovering around 16. Dealer tech checked my Livewire temp readings against his Ford computer and they were identical. WHAT GIVES?? What else could be causing this issue? Does the sinister cooler allow for greater deltas? At least when the EOT climbs to excessive (ie 235) the cooler does drop the temps back down fairly quickly once the load is relieved.
-I'm tempted to just accept this as the new normal, since 2 new coolers are both giving me this temp spread, especially since the EGR has been removed. Your thoughts, advice and guidance are welcome. Thanks

 

I just replaced my cooler also, unfortuntly i didnt get sinister, but ended up getting the "upgraded" ford cooler (it has one more plate in it...whoopie doo). Ive noticed the same thing. My delta is about the same as it was before. This thought popped in my head, what about the temp sending unit. Could it be bad? The other day I was loaded up too 23k gross and it didnt like the hills at all, puked coolant just like it did before.This just after i had the oil cooler replaced, egr cooler replaced, ipr valve, and a few other things. I also had the ficm sent out to ficmrepair, got that fixed and tuned with an atlas tune. So i realize im making a little more heat, but grrr this puking is bugging me. Im trying my best to check/look for anything else before i hang my head and make plans for head gaskets and studds. Oh and i put a mbrp 4" from the wheel back on it.

 

have you tried switching sensors?

 

Sounds like hgs are in your future.

Sent from my leash using IB AutoGroup

 

If the sensor switch doesn't yield anything might want to take a look at the oc bypass valve.

Sent from my leash using IB AutoGroup

 

Yep, bad oil cooler bypass valves...

Josh

 

You've got my attention. I found this thread https://www.ford-trucks.com/forums/1...***-valve.html about the oc bypass valve. It looks like the OP eventually had to replace the OC again. I need thoughts like these about where else to look. In a related thought, If I just accept this as the "new normal" and my oil temp never exceeds 240(briefly pulling loads up a mtn) how serious is this issue?

Also, help me wrap my head around this issue. How does the OC bypass valve in the filter housing affect temps?

 

Thanks. Looks like I have something to pursue. How does the bypass valve affect temps?

 

The by-pass allows oil to bypass the cooler, therefore no or very little oil is getting cooled.

I cannot remember if that piece is available separate or a new base is needed.

Josh

 

Valves are not available separate. You must replace the whole oil filter base(for a $3 valve).

 

Edit..wrong bypass valve

 

Edit..wrong bypass valve

 

Edit..wrong bypass valve

 

Please, for all that is holy, hope that piece is all that I need (vs a $250 housing). It looks like the diagram on p2 of the above posted thread link shows 2 different valves.

 

Oil cooler bypass is all brass and no longer serviceable.

Josh