2006 F350 - auto trans - 210k miles - stock head bolts and gaskets (definitely head BOLTS, original as far as I know)
Owned it for about 10k miles at this point, has a new oil cooler, EGR
delete, coolant filtration kit, CAT
ELC coolant, fairly new Stant degas cap
Towed about 1500 miles last week through some mountains, started at about 6k feet elevation and dropped down to sea level
Coming down a mountain I popped the hood for a look at the gas station and noticed a little bit of coolant coming out of the degas cap and the coolant level was higher up than usual, about half way between the stock low and high level marks. I usually keep the coolant level half way between the low level mark and the bottom of the bottle. I wiped it off and kept going on my way
When I got to my destination, everything looked good so I shut it off for the night. When I came back the next morning after it sat for 12 hours or so, the rad hose still had pressure, so I opened up the degas cap and a bit of pressure escaped. The coolant level had returned to normal though.
Is this a sign of a slightly leaking HG? Or am I just being paranoid?
The signs I noticed were - A bit of coolant out the degas cap and cooling system pressure remaining overnight.
I monitored everything on the TorquePro app and the coolant temp never went above 210 even when towing up the steep grades. Coolant and oil temp were never more than 15 degrees apart and usually stayed about 3 or 4 degrees apart. Coolant and oil are both clean, no mixing there. Coolant level isn't dropping, so I'm guessing no coolant consumption. And no white coolant smoke out the tail pipe.
Think it's alright? Or should I start saving up for a stud and HG job?