Elise K Series HGF - again!

[trickymicky]

Hi All,
I've had an excellent 3 years with my K-series Elise, during which it's been remarkable & trouble free.

However, the mechanic pointed out that it was smoking when I dropped it off for its 72k mile service.
So, it had HGF at that time (3 months ago) and was all sorted for me.
A few weeks ago it developed a misfire on start-up, but this always cleared in a minute or two.
It's recently been using a little coolant - needing a top-up once a week.

Last week it started misfiring & spluttering, smoking too, & I did drive it about 2 miles to get it home.
The Engine Mgt Light came on when the misfire got a bit worse.

My mechanic showed me the old gasket, but both of us couldn't see where it had failed.
After watching a youtube video, I am thinking it may have been oil affecting some elastomer sealing - may have to go & look at it again.
Anyway, the mechanic (who knows elises very well) has fitted an MLS gasket this time.
However, there is still a misfire on cyl no. 4, although the spark plug & coil pack have been changed.
Also, the exhaust / cat got very hot - causing smoke from the boot insulation.

He's going to continue investigation tomorrow.

Has anyone come across this before?

Might I have got a cracked liner, or some other malady this time?

Thanks.