6th Gen ('00-'05): Failed compression test on L67
#1
Failed compression test on L67
So I posted recently about a cylinder 6 misfire, thinking it was probably a fuel injector. Instead I found that when a compression test was run, it could only withstand 40PSI. Right now I have the motor kinda torn down (intake manifold and valve covers are removed), and I really don't want to remove the rear head if I don't have to. You guys have any idea what it could be, maybe something easier that I could check first?
#3
So, im curious... What would be the fix for this? New head?
#4
Doesn't NEED to be a new head, but the cost of pulling the head, getting it to a machine shop, and getting new valves placed while getting the heads clean... you probably would be better off just getting a new set of heads for these engines.
Unless you are doing the work yourself, in which case you are just cleaning and replacing the parts, and making sure it's not warped in any way
Unless you are doing the work yourself, in which case you are just cleaning and replacing the parts, and making sure it's not warped in any way
#5
If it's a bad valve you can send the head out and they will machine the valve seat and replace the valve, but its probably cheaper to find another head. I would have done a leakdown test before tearing anything apart. It would have told you if you have a bad intake valve, bad exhaust valve, bad piston/rings or possible bad gasket. If you have minimal leakdown but low compression that points to valvetrain problem, broken valve spring, worn cam lobe, etc.
#7
I had a shop do it, they said all 5 of the other ones were close to 160PSI.
#9
Wound up getting it all off, pics here: https://imgur.com/a/iVap8lm
There's some graphite from the head gasket left, I circled it in red. I think it was head gasket, just want to get your opinions on it since it's my first time dealing with low compression.