Mazda Talk Forums

Posted: **Tue Nov 22, 2011 8:58 pm**

I've been getting ready to do my turbo install on my 2007 NC. Today I did a compression test and to my dismay, cylinder 4 is low. It is giving 188psi and the others are all around 200psi. With some engine oil in there it went up to 200psi. However putting some engine oil in cylinder one made it go from 200 to 230psi. I'm not really sure what to do at this point. Boost it anyways?

The engine has 25k on it, and I did my best to break it in properly when new.

Posted: **Wed Nov 23, 2011 5:32 am**

Yes, boost it anyways. That's normal variation for a production motor with some use on it. My number 4 cylinder is similar.

Posted: **Wed Nov 23, 2011 4:29 pm**

gotcha... alright stand back everybody!

Mazda Talk Forums

low compression number in 1 cylinder

low compression number in 1 cylinder

Re: low compression number in 1 cylinder

Re: low compression number in 1 cylinder