Official TN Member
Join Date: Oct 2017
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 313 Post(s)
Thanked 149 Times in 123 Posts
iTrader Score: 1 reviews
Move the crank to 90 degrees after TDC, use a breaker bar to hold it in place, then blow compressed air into each cylinder and see if it will hold pressure.
Pull the valve cover off and move the camshafts so that each cylinder has both valves closed when you air up THAT cylinder. The cam lobes need to be 180 degrees (opposite side) of the valve buckets or rockers depending on what it has for the valve to be closed. No interference will happen with the piston 90 degrees from TDC, unless it has more than 4 cylinders. You can check it with a long rod down the plug hole.
Also look for excess gap between the cam lobe and the bucket-rocker or whatever transfers the lobes force to the valve stem. Sure sign of a bent valve.
On a quarter million mile VW, do yourself a favor and junk it, like you posted already.
Last edited by Old Mechanic; 07-12-2019 at 07:05 PM.