mot emissions failure, head gasket?

[Dogbot]

oily plugs wouldnt be down to head gasket,
could be due to valve stem seals leaking into the chamber overtime but then, that would be gone after a few mins of running, sounds to be using a lot if you did less than a litre in 500 miles... but then its hardly beeing driven to notice,

if it was mine mate, id have it back drop in some fuel system cleaner, an give it a fecking good spanking about for an hour or so, then have the emissions tested......

[nathanpotato]

oily plugs wouldnt be down to head gasket,
could be due to valve stem seals leaking into the chamber overtime but then, that would be gone after a few mins of running, sounds to be using a lot if you did less than a litre in 500 miles... but then its hardly beeing driven to notice,

if it was mine mate, id have it back drop in some fuel system cleaner, an give it a fecking good spanking about for an hour or so, then have the emissions tested......

Cheers for the reply I think i will do what you said then just take it to another test centre and see if it fails again. I noticed today that the temperature light was flashing for about 10 mins when i first started the car and it was running. However after the temp got to 90 and i turn the car off and started it again the light was fine. 

[Dogbot]

Check the water level dude, that could be low water level flashing, water level rises when warm...

But with all that you have replaced can't think of anything other than lack of use that's causing it,