2006 Forester- new headgaskets but oil leaking from cam seal

[Stevo F]

I had my mechanic install new headgaskets on my 2006 Forester X, naturally aspirated EJ253 and automatic transmission, as the headgaskets installed by a previous shop had failed internally, causing it to start overheating shortly after I bought it. I had my mechanic install the thicker MLS Subaru OEM headgaskets for the EJ255 turbo, as I was advised these would be better than the single layer OEM gaskets that originally were installed with this engine. He also replaced the front cam and crank seals.

Once it was done, the car ran well except for an occasional rough idle at startup with an P0304 code, but ran well after the first 30 seconds, with no codes after that. Also, there were no more bubbles in the overflow tank, and no more overheating, so the headgaskets seem to be sealing well. What had developed, however, was a drip from the front of driver's side head which would stop a minute after shutting off the engine. My mechanic, pulled the front of the motor apart, replaced the cam seal a second time with sealant and still leaked. He then resealed the part fo the head that is removed to remove the camshaft and it still leaked. Since the camshaft, was scored a bit where it had contact the front seal, we replaced the cam with a new one and a new seal and the leak persists. It does appear that the oil is leaking around the camshaft, vs. from outside the cam seal itself. 

My mechanic is thinking maybe there is excessive oil pressure in that head which is causing oil to breach the cam seal, but can see nothing wrong or no blocked oil passageways in the head. Has anyone run into a persistent front cam seal leak before ( a total of 5 cam seals have been installed so far).Any ideas?

[idosubaru]

1 hour ago, Stevo F said:

I had my mechanic install new headgaskets on my 2006 Forester X, naturally aspirated EJ253 and automatic transmission, as the headgaskets installed by a previous shop had failed internally, causing it to start overheating shortly after I bought it. I had my mechanic install the thicker MLS Subaru OEM headgaskets for the EJ255 turbo, as I was advised these would be better than the single layer OEM gaskets that originally were installed with this engine. He also replaced the front cam and crank seals.

Once it was done, the car ran well except for an occasional rough idle at startup with an P0304 code, but ran well after the first 30 seconds, with no codes after that. Also, there were no more bubbles in the overflow tank, and no more overheating, so the headgaskets seem to be sealing well. What had developed, however, was a drip from the front of driver's side head which would stop a minute after shutting off the engine. My mechanic, pulled the front of the motor apart, replaced the cam seal a second time with sealant and still leaked. He then resealed the part fo the head that is removed to remove the camshaft and it still leaked. Since the camshaft, was scored a bit where it had contact the front seal, we replaced the cam with a new one and a new seal and the leak persists. It does appear that the oil is leaking around the camshaft, vs. from outside the cam seal itself. 

My mechanic is thinking maybe there is excessive oil pressure in that head which is causing oil to breach the cam seal, but can see nothing wrong or no blocked oil passageways in the head. Has anyone run into a persistent front cam seal leak before ( a total of 5 cam seals have been installed so far).Any ideas?

A new cam, new cam seal, and it still leaks from the ID of the seal?  

Wow. 

I'd wonder if the cam carrier is allowing the cam to walk or is otherwise distorted?  Cam carrier/head may need replaced?