[Bill 🌳]

Hoping to get some help in this great forum. Spent all day yesterday replacing the valve cover gaskets to try to stop an oil leak on my 2007 3.5L ivetc EXL with 110K. After several hours and a few trips to the store finally got it completed and definitely fixed one oil leak on the back valve cover. However, when I started the car to check it for leaks on my work I still have one leak which is not coming from the front valve cover but seems to be coming from the studs that attach the O2 sensor housing to the engine. If I start the car and watch it I can see it slowly seep onto the threads. I haven’t been able to find anything online about this although I have seen other people complain about the same issue but couldn’t find an answer. I hope this isn’t a major problem, any help would be appreciated as to what to do to fix this. I’ve attached a pics.

 

[celicool]

If I were replacing the rear valve cover gasket (facing the firewall), I would definitely replace the front valve cover gasket too.

The oil leak could also come from the PCV valve which is right there. Are you 100% positive it's not coming from your front valve cover gasket?

 

[Bill 🌳]

I replaced the front gasket as well. The seam is nice and dry above the O2 sensor so it’s not coming from the front valve gasket. And a brand new PCV valve was also installed. No leaks from that either. Took O2 sensor out and dry as a bone. Also swapped out spark plugs while I was in there and they were all dry.

 

[celicool]

Well, then I would not know where the oil come from. Could it be the remnant of old oil leak? or Cracked valve cover ?

 

[kaimanson]

I would clean the all area completely and keep an eye on the area again to confirm that the leak is coming from the cover.

 

[marvinstockman]

Are these leaks winding up on the ground?

What you can do is clean the engine, add oil leak detection dye, run van as instructed in kit, and with UV flashlight, you'll discover where the leak is coming from. Kind of like magic!