High pressure in coolant system???

I have d13 volvo 2012 problem with shacking vibration while driving oh 45 to 50 mph in 11 gear and 50 to 55 in 12 gear, combustion test was postive exsost in colant in reservoar and separator is really dirty almost black no losing collant at all.
Do yo think that bad injector cap can be the problem

 

I goot antifrise lik in intertake what can bi

 

I goot volvo d13 2011 and it liking colant in intertake wat can bi

 

EGR cooler.

 

I just noticed very similar problem on my truck.
Today when I started a cold truck I can see bubbling air in coolant tank. There is pressure in coolant tank. I just noticed that I see little leaks on hose connectors and coolant filter. I can see that after the truck warms up there is less bubbles in the coolant tank. Truck is 2014 d13 with 390k miles. Any suggestions or know problems with this symptoms.

 

D13 have a known issues with the injector cups

 

Not so...I changed my cups, and air compressor is fine.

 

Only 3 things can put HIGH PRESSURE AIR in the expansion tank
Injector cups
Air compressor
Head gasket...

Injector cups MOST of the time will turn coolant dark. ( exhaust gases i e soot)
Air compressor Head gasket is most likely
On a d12d it will never be the head gasket...

 

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