Warranty Service

[cpttimerestraint]

My buddy has a 2010 Silverado that is having AFM/ misfire issues.  He had purchased the GMPP for 7 years.  When the P0300 error code first came up and he took it to the dealer, the truck was still under the extended warranty.  They told him that it just needed a tune up and spent $600 and got it fixed.  The issue came back again in November with the same P0300 error code when a different dealer charged him $600 to replace the valve covers.  Now, the same code is back again and they are saying that he needs to spend $8K on a new engine.  The truck only has 61K miles on it.  Between the original trip to the dealer and now, it has been 11 months and 6K miles.  

 

My question is if you report an issue under warranty and then the warranty expires, how long do you have if the same issue keeps coming up?  We both feel like they should cover the repairs since the issue arose  and was reported while the truck was under warranty.  It has been the same error code every time.  Is it the regular 12 months, 12K miles that most serve carries?