Hello, my S70 is missing. I changed plugs and realized that cylidner #2 is not firing. I bought a new coil and it is working but still cylinder is not firing.

I checked compression and it's only 30lbs in this cylinder. It is 150lbs in all other cylinders. (compression check is engine idling).

However when I rev the engine cylinder #2 compression does go up to 130lbs.

Do I have a stuck or burnt valve?
What is next step? If I do have to remove head and do a valve job what special tools are required to remove cylinder head and then reassemble on engine?

Thanks for any and all help!

 

I would say burnt valve.

 

My daughter's 98 S70 GLT developed a similar problem yesterday. OBDII code shows #2 cylinder not firing. But the issue is intermittent. I am hoping it is a failing plug wire.

 

very doubtful it's a valve.

This has been a frequent issue on other forums and this one as well. Common fixes have been spark plugs back to OEM, fuel regulator relay, coil or plug wires. Sometimes even the cam postioning sensor but that would throw a code I believe. Even one had a bad injector

 

It is a burnt valve on #2 cylinder.

 

I have done many burn't valves on the 960, and S70.

 

Put in new plugs last night and it seems to be fixed.