Burnt Valve/Head Gasket

[CayenneTT955]

Hello,

 

Well, Porsche gave me the diagnostic.  Cylinder 3 has 95% leakdown caused by a valve problem all other cylinders in spec.  There are no engine problems other than that issue.  They said it could be a burnt valve but that there is significant carbon.  I'm hoping for an easy solution, but if I need the head repaired, any insight into how serious a cylinder head R/R job is?  Are the head bolts reusable?

 

The history of the car is poor maintenance.  When I changed the plugs and coils, every single coil was cracked, and they were the worst spark plugs I've ever seen.  I'm hoping if I do a seafoam/water steam clean that the carbon will break free and seal back up.  If not, I'll do the head I'm not that worried about it.  Let me know your thoughts.

 

-Will

[JFP in PA]

1 hour ago, CayenneTT955 said:

Hello,

 

Well, Porsche gave me the diagnostic.  Cylinder 3 has 95% leakdown caused by a valve problem all other cylinders in spec.  There are no engine problems other than that issue.  They said it could be a burnt valve but that there is significant carbon.  I'm hoping for an easy solution, but if I need the head repaired, any insight into how serious a cylinder head R/R job is?  Are the head bolts reusable?

 

The history of the car is poor maintenance.  When I changed the plugs and coils, every single coil was cracked, and they were the worst spark plugs I've ever seen.  I'm hoping if I do a seafoam/water steam clean that the carbon will break free and seal back up.  If not, I'll do the head I'm not that worried about it.  Let me know your thoughts.

 

-Will

 

Have that cylinder bore scoped.  These engine's are known to scuff cylinder walls or even turn the cylinder slightly oval under some circumstances.  If the wall is scuffed, de-carboning is not going to get you much.

[CayenneTT955]

1 hour ago, JFP in PA said:

 

Have that cylinder bore scoped.  These engine's are known to scuff cylinder walls or even turn the cylinder slightly oval under some circumstances.  If the wall is scuffed, de-carboning is not going to get you much.

 

The dealer did do that.  They said there was slight scuffing but the issue was most likely valve related, especially because all other cylinders were fine.  The engine also doesn't seem to burn any oil or make any strange sounds (piston slap, etc)  Also, the engine runs what I would consider perfectly at higher RPM/under boost.  It also runs a lot better now that I fixed the one huge vacuum leak.

 

-Will