Is it a PCV Valve or Engine Seal Causing Oil Leak

[Michael Murphy]

Hello out there,
I love my 2010 Sport Trac XLT 4.0 with 173,000 miles on it.
I am getting an oil leak that someone said it probably was a rear main engine seal.
After some research I learned that a clogged PCV valve might cause oil leaks.
So, I am reaching out to my fellow Explorer and Sport Trac'ers to get better informed and less confused.
If the oil leak is due to the PCV valve, this is the one the Ford Parts specify for my vehicle (Motorcraft PCV Valve - EV261), could someone reply with how to replace it correctly. And how often should this part be replaced?
If the oil leak is due to the main rear seal, does Bar's Leaks Rear Main Seal Repair work?
And if the seal repair does not work, what does it take to remove and replace the main rear seal, what should also be replaced at the same time, and if possible give me a ballpark cost to get it done?
Thank you for your time and help,
Murph

 

[Michael Murphy]

Hello out there,
I love my 2010 Sport Trac XLT 4.0 with 173,000 miles on it.
I am getting an oil leak that someone said it probably was a rear main engine seal.
After some research I learned that a clogged PCV valve might cause oil leaks.
So, I am reaching out to my fellow Explorer and Sport Trac'ers to get better informed and less confused.
If the oil leak is due to the PCV valve, this is the one the Ford Parts specify for my vehicle (Motorcraft PCV Valve - EV261), could someone reply with how to replace it correctly. And how often should this part be replaced?
If the oil leak is due to the main rear seal, does Bar's Leaks Rear Main Seal Repair work?
And if the seal repair does not work, what does it take to remove and replace the main rear seal, what should also be replaced at the same time, and if possible give me a ballpark cost to get it done?
Thank you for your time and help,
Murph

...also, does using synthetic oil contribute to oil leaks?

 

[swshawaii]

Best way to find the oil leak is thoroughly clean the engine. Gunk aerosol seems to still be effective, although some feel the old formula was better. After spraying the Gunk and letting it soak, rinse with low pressure water and dry off with compressed air or even a leaf blower if one is available. Running the engine at operating temperature will evaporate any remaining residual water. Common oil leak with the 4.0L SOHC is from the valve covers. Usually occurs towards the rear closest to the exhaust manifolds. Lower and upper oil pan gaskets are also common, but can usually be ruled out if the oil drips are under the bell housing. Clogged PCV is possible if it's never been replaced at 173,000 miles. I have a very slow rear main seal leak likely caused by non use of the vehicle for extended periods of time. Leak is only around 8 ounces per year, but annoying because it will occasionally drip on the front catalytic converter and smoke. Also drips on concrete. Tried Rislone/Bar's Leak and ATP with little effect. Last time was Blue Devil that worked 100% for about one week. I'll need to pull the motor to replace that PITA $20 seal. I'll live with it or pay a friend $1000 to do it for me. Urban myth is that synthetic oils cause leaks.

 

[Michael Murphy]

Best way to find the oil leak is thoroughly clean the engine. Gunk aerosol seems to still be effective, although some feel the old formula was better. After spraying the Gunk and letting it soak, rinse with low pressure water and dry off with compressed air or even a leaf blower if one is available. Running the engine at operating temperature will evaporate any remaining residual water. Common oil leak with the 4.0L SOHC is from the valve covers. Usually occurs towards the rear closest to the exhaust manifolds. Lower and upper oil pan gaskets are also common, but can usually be ruled out if the oil drips are under the bell housing. PCV is possible if it's never been replaced at 173,000 miles. I have a very slow rear main seal leak likely caused by non use of the vehicle for extended periods of time. Leak is only around 8 ounces per year, but annoying because it will occasionally drip on the front catalytic converter and smoke. Also drips on concrete. Tried Rislone/Bar's Leak and ATP with little effect. Last time was Blue Devil that worked 100% for about one week. I'll need to pull the motor to replace that PITA $20 seal. I'll live with it or pay a friend $1000 to do it for me. Urban myth is that synthetic oils cause leaks.

Thanks for the info and reply.