Please read for context as I am looking for possible next steps from what has already been done.

Issue:
Since the recent work below, I have had High (no load) & maxed (under load) degas pressures. Under load oil temp spikes up to 20 degrees delta from coolant temp under load & uphill etc. Normal driving (no load) highway degas ~12-13 constant with uphill taking it to 14-15 then settles down to 13. The degas cap is NOT puking in anyway & is releasing pressure at 16. Cooling fans & TSTAT is working as designed.

Recent Work:
I had a shop do a head gasket job due to a failed coolant block test. So I chose to upgrade some things as well replace some other things that were already upgraded just in case. Below are the parts list. Note I run Cat ELC + distilled water as well Rotella T6 for fluids. I also have oil & coolant bypass from Sinister, Sinister Degas aluminum tank.

New:

• PowerStroke Heads & Gasket Set
• New set of ARP Studs (Yes I had ARP already but it was the 3rd HG job so thought I would change them again just in case)
• RDS Thumper 1 HPOP
• Odawgs Diesel Air Intake
• BDP OEM Oil Cooler (This is what I had prior as well & NEVER saw more than a 10 degree delta between Oil & coolant temps but wanted to replace because I was in there)
• New stock Motorcraft IPR Valve
• New stock Oil Pressure Switch
• New Motorcraft TSTAT
• New Blessed Performance Tunes (FICM + SOTF) configured for gas mileage & towing (not for business on regular basis)

I had a few small coolant leaks after the HG job but resolved those & then also replaced the TSTAT as a simple item.
I have just taken an oil sample & sent off to see if its burnt or has coolant in it etc. since its only been 3K miles since the job was done, but the degas pressures have been high the entire time so I have been monitoring.
I have not yet parked on incline to see if any coolant is sitting under my EGR valve which I believe would indicate a cracked EGR cooler but I have the BDP EGR cooler & dont think I have ever heard of it failing.

My gut tells me I likely have something clogging the new BDP Oil Cooler or a clog in the cooling system somewhere & or there is a hose letting air in. If I have to go back in & look at something, I may just add the BDP Oil cooler & or replace the Turbo as well.

I may also try a coolant flush \ backflush & replace with new fluids to see if that helps & I could replace the bottom rad hose which OEM has failed before causing me high degas pressures. Could also be the hoses getting old on the Sinister kit.

Questions: If a turbo leaks oil, would that impact the oil temp which then have any impact on degas pressure? I saw what looked like wetness below turbo, but have not had time to get in there.

Anyway, any thoughts on how to next best attack this would be appreciated as I cant be hauling much or degas maxes out.

I have attached some pics both at idle, around town or under load with various data points so you can see that its primarily the degas pressure with the issue + some minor spikes in the delta temps of oil & coolant.

Thanks in advance

 

Your DELTA looks fine, your degas pressure isn't bad the degas cap should be 16 LB. So anything under that is OK, I think the general rule for DELTA is 10% difference your well within that, I my ave to look into that EDGE I like the display. I run an old scangauge.

 

Just because the cap is rated for 16 psig doesn't mean it should be there. If the system is working as it is designed, pressure is generated only by the expansion of the liquid (when it heats up) pushing on a fixed volume vapor space. Normal pressure when working an engine hard should not be over 12 psig IMO. I rarely see over 8 psig.

Where are you keeping the liquid level in the degas bottle?

We know how much vapor space is needed for the OEM degas tank, but I have no idea what liquid level you should run in your Sinister degas bottle. You need a minimum of 3 quarts vapor space when cold, and preferably 4.

Too little vapor space will cause high pressure because the expanding liquid will compress it significantly before the cap relieves.

Pure water (instead of 50/50 antifreeze) can also cause abnormally high degas pressure because of flash boiling on the very hot internal engine surfaces.

If it isn't one of these issues (assuming the pressure measurement is accurate), then it might be head gaskets (even though I know you don't want to hear that). Note that I am assuming a properly deleted engine (no EGR cooler).

The best way to check for possible head gaskets is to get the entire engine fully heated up, and then carefully vent the pressure from the degas bottle. Then take it for a drive with a few spirited accelerations. If these accelerations get you back to the cap relief pressure, then it is most likely a head gasket sealing issue.