Is this a cracked cylinder head?

[Partyguinness]

Hi everyone,

Bought my first Lexus in June. Just wanted a well priced runaround after I had to give my 2020 leased BMW back. Picked up a petrol 2005 GS300 auto with 116k on the clock. Immaculate condition and very happy with it. FSH and MOT until next June.

Recent weeks I have noticed a drop off in power and while the rev counter needle moves there is a definite lag in power between accelerating and the car is straining for power. Gut feeling is that the transmission is worn but anyway...I decided at the weekend to change the spark plugs (and spray electrode cleaner on at the mass air sensor) and I stuck a borescope in and not surprisingly all the piston heads are caked with carbon build up which I was always aware is a problem with pre 2007 models.  But later on as I was scrolling through my pics I noticed the attached pic. Ironically that is the cleanest pistonhead but the the seals looked gone and does that look like a cracked cylinder head along the top of the picture?

No issues with oil levels and coolant.

Thanks,

eml

[Partyguinness]

[Spock66]

I'd suggest trying a compression test.