Question: I have a 2001 Ford Escape V6 with 200K miles. I have oil on 3 out of 6 plugs and coils. I have changed gaskets and tube seals and still have oil leaking by. Would it work if I put RTV silicone around tube seals
on valve cover side and engine block side?
Answer: Yes, you can try just a little bit of RTV to seal the oil leaks around the spark plugs and ignition coils. But, the fact that the gaskets are not sealing tells me that there is something else wrong. The engine in your Ford Escape may have too much crankcase pressure. This would cause oil to leak past seals. Check that the PCV system is not plugged or restricted. If it is, this would cause high internal pressure.
You would need to clean out the passages to make sure the PCV system is flowing easily. Also, make sure the oil is not contaminates. That can cause seals to either expand or contract, depending on the type of contamination.