Cylinder 3 misfire!

[Abbie Loram]

I was hoping someone could help - I have a 2.0 petrol non turbo Impreza GX Sport and I have a cylinder 3 misfire. Oil is leaking into the cylinder chamber. I sent it to Subaru as I thought they would be able to tell me what was causing the problem so I could fix it myself however they do not know what it is. They did a compression test and still don’t know where it’s coming from. Has anyone had this problem or know what could be causing it? Also would it be worth just buying a new engine? 

[stuartie]

Could be a few things letting oil in to the cylinder, could be valve guide's, piston rings worn or cylinder head gasket or cracked block, what did the comp test on cyl 3 say? Was it much the same as the other cylinders? 😎👍

[Abbie Loram]

Subaru only said that cylinder 3 had no compression. The 3 other cylinders have no issues. I think I’ll start stripping this engine as I’m finding it quite difficult to find a new one! 

[stuartie]

No compression would most likely be a hole in the piston or the piston crown has broken off and stuck at the top of the cylinder, i'm not sure if the non turbo engine has the same fault as the turbo engine as in it can run lean on cyl 3 as its the last in line to get fuel 😎👍

[stuartie]

If they say there's oil in the cyl and no comp i would go for hole in the piston, you don't know of a garage with an oscilloscope thingy that could look inside through the spark plug hole just to see if the piston ok 😎👍

[Abbie Loram]

I do have a friend with one that could possibly lend me it to have a look! Only thing I’m abit sceptical with it being the pistons as it’s a non turbo So it’s finding the reason behind it being the pistons!