...Crap design simple as that;shame Porsche didn't get Honda to do the engine and I am not joking!
I too am in the same boat but ims killed mine with a final bill that will be close to £18k so your bill is tiny!!
I had all six liners changed,pistons,rings,aos,low temperature thermostat,all oil pumps,all variocams,guides, New ims shaft and bearing with new housing,I had my heads completely stripped and rebuilt with new guides,refaced valves,stem seals etc.
My hard lines are in good condition; a corollary of a low mileage car that lived in a garage I presume?
Plugs and coils if they are tired ? Also get the exhaust fastenings changed , New engine mounts if yours are tired? Mine were changed...
My love for these cars has totally gone now I am afraid thus despite the huge cost and loss I am selling mine (it's on this forum) as can't forgive it sadly...stupid I know but there you are.
I wish you luck with yours...