I have a 94 mark viii with a 4.6l DOHC that started making very loud tick all the time. I checked rod bearings, timing chains and removed one lifter at a time to narrow it down to a cylinder and can't find anything wrong. It has good compression and good oil pressure. The sound seems to be coming from the top of the intake, the front of the engine and at the exhaust manifold when I use a stetoscope.
Hi well if you have checked everything else this could be a valve spring or even a valve guide prob. Also possible a exhaust leak. Not likely but I have seen it.
April, 26, 2012 AT 4:13 AM
Just had the same thing happen to my 95 mark 8. Found the problem in the intake cam, not getting oil. Mine locked up. The cam was siezed. It started making a ticking sound and the engine just locked about 50 miles later. I honed everything and cleaned the cam. Found the oil journals cloged and cleand them. Put all that crazy timing chain back in and did a good oil and filter change. Was back on the road the next day.
April, 26, 2012 AT 5:29 AM
You may have dropped a valve seat on top of a piston