Dodgy idle/ possibly running on 3 cylinders

[Chrisjk]

Just took my RSi out on a run and its really missing a beat, on idle its very juddery so i assumed idle control vavle was at fault but even when driving it sounds and fells like its not running smoothly. Other than spark plugs and coils what can i check?

 

[Chrisjk]

bump

 

[mark.k@GDI]

head gasket? check coolant for oil film and check oil cap for thick residue. Coil pack, wiring to sensors. Lots of checks to be done. Best bet is pop it to a local garage and get the fault codes checked!

 

[mattjk]

I'd check first

plugs
leads
coilpacks
TB
is it doing it hot or cold?
maybe exhaust sensor unlickely though.

After then unsure...