No Compression in Cylinder 1. It is what I think it is...isn't it :(

[nurse_27]

Hello,
Ok so I purchased my 07 CX-7 in January. Just turned 106k. No problems until now, died while driving. Apparently previous owners/repair shop did not put lock tight on the crank bolt when they worked on it (whatever they may have done). Crank bolt backed out separating the 3 washers behind it. Replaced the crank bolt (as it is one time use only) and the 3 washers behind it with new. Vehicle had remained in time, chain was still in place, tight and all marks in place. Also used the special timing tool to hold the cams in place during repair. So all back together. Now I have Cylinder 1 Misfire code. Replaced spark plug, checked ignition coil (switching out with another ignition coil, misfire did not follow). Also I do have spark. Next step was compression test...Cylinder 1...0 psi :'( Cylinders 2, 3, and 4 all have 150ish. Cylinder 1 has NONE. So I'm thinking bent valves? I have rough idle and horrible ticking which was not there before and I'm assuming is the valves possibly bent in just the right position that they are still trying to move a little? Just my luck. Any ideas what my next step is? I'm thinking pull the head but I want confirmation first. Thank you

 

[Chico6911]

Hey nurse_27

I have a similar problem with cylinder 3.

Compression is at 65psi. Cylinder 1, 2 and 4 are around 135psi.

My mechanic recommends engine rebuild and he thinks I fried a piston ring. In cylinder 3 there is cooling seeping in.

I just got off the phone with Mazda and they told me in the nicest way possible they will do nothing for the car ( I am 9 thousand kilometers over the warranty and a few months after the date) but if I want I can pay them to diagnose it for me or trade it in for a new one... HA!

If you have any good news or a better idea of how to fix please share. I don't want to spend 2-4 thousand to rebuild the motor.

 

[Chico6911]

So does anyone have any insight on this issue? Anyone with similar problems? Any recommendations?

 

[sticka69]

there was a TSB about the front crank bolt but as for misfire on any cylinder, I am dealing with mine now on cyl #3. bought new in 2007 and just went over 86k miles. I have ext warranty so we will see if Mazda will come thru again (AC compressor, timing chain).