Need some help troubleshooting what could cause low compression on 2 cylinders. Performed a compression check last night and found that the two cylinders on the passenger side have only 15# of compression. The two on the drivers side showed 118# & 108# which I assume is good. Any deas what would cause low compression on two cylinders on the same side? I'm thinking valve/head issues but I'm not sure. Also what is normal compression for a ea71?

 

Thanks....pete

I'm no mechanic but in my research I've heard low compression is usually either valve adjustment or worse burnt rings and bearings. I'm getting oil blowback out of the top of mine and loss of power, i hear thats usually the cause. This could be different for boxers, i'm not sure yet, but if i find more info I'll post up. I'm sure the resident experts can help,(hint hint) it's a common engine problem.

I'm no mechanic but in my research I've heard low compression is usually either valve adjustment or worse burnt rings and bearings. I'm getting oil blowback out of the top of mine and loss of power, i hear thats usually the cause. This could be different for boxers, i'm not sure yet, but if i find more info I'll post up. I'm sure the resident experts can help,(hint hint) it's a common engine problem.

 

Ok thanks for responding...

Seeing how adjacent cylinders are both poor,head gasket leaking compression between them is a possibility.