I thought ChevyMgr or someone dealer related might have some insight to this question. My P0304 code turned out to be bad valve/seats on cylinder #4 and #3 following close behind to fail next (37,700 miles). Apparently this is somewhat common on the L61 per a recent hire at this dealer from a Saturn dealer. My question is, Adviser said that they are sending the head out (sublet) to an outside machine shop to have it repaired. Is this normal practice? Years ago when I worked as a tech at an Oldsmobile dealer and then and Olds Cadillac Dealer, we fixed heads right there at the dealer, or replaced it with a brand new one. Of course I realize this is newer technology. Thanks in advance

 

We are seeing more and more burnt valves. Usually #2 cylinder, but not always. We never send the head to a machine shop, always replace.

 

Thanks for the reply, Just to clarify, you mean if a head cannot be repaired by replacing and lapping valves, seals, guides etc., you guys replace the whole head correct? Now I wander if the head has cracks. That is what happened to my 1995 S10 2.2L last year, It was way out of warranty though. At 128K miles I pulled the head and discovered It was already rebuilt. (I bought it w/ 78K on it) It had crack in the #2 chamber between the valves. Replaced it w/ a new aftermarket head. Now I am wandering, guess there is no telling for sure unless I watch the guy do the work.

 

If you could of thought of it ahead of time (hind sight). You could have marked it with a punch, or engraver type tool before hand. That way you can tell if its the same head, or not.