[Subaru impreza STi]

 

[Ichabod0525]

There are many possible sources all of which are higher up. Oil filter / housing / mount, vacuum pump, Cam cover, Oil cooler. Disassemble, inspect and replace as necessary. A little easier to view right side up

 

[Subaru impreza STi]

There are many possible sources all of which are higher up. Oil filter / housing / mount, vacuum pump, Cam cover, Oil cooler. Disassemble, inspect and replace as necessary. A little easier to view right side up View attachment 131788

I did some inspecting , pretty sure it’s the vacuum pump the “wetness” / sludge stained look starts right underneath there

 

[Subaru impreza STi]

My cars a manual

 

[Boomer Guy]

The vacuum pump does not care what it drips on, automatic or manual. The good news is, the manual transmission makes it easier to remove the vacuum pump to replace all 3 gaskets. If the front one leaks, the back one probably does, too. I found out the hard way when I replaced only the front one. There are several YouTube videos on how to do this.
If you want to prevent all future leaks, you can delete the vacuum pump altogether and source the vacuum for the brake booster from another place. There are a couple ways to do this. I chose the easier one with the IE Blocking Plate Kit.

 

[mkIIIvw]

Try the vacuum pump or one of the gaskets. I had similar issue and it was the valve cover gasket.

 

[Boomer Guy]

Try the vacuum pump or one of the gaskets. I had similar issue and it was the valve cover gasket.

If it is the valve cover gasket, it is an easy fix. You can get a complete OEM valve cover from Amazon which includes the cover, gasket, bolts and PCV valve (which usually dies when the gasket dies) in one box. There are YouTube videos on this and is not that hard of a job for the DIY person. Just be sure you use a torque wrench and follow the tightening pattern when you put it back on. Don't just "go around in a circle.

This is the one for my 2008 with the 2.5 CBTA engine:

Amazon.com: Genuine OEM Volkswagen Valve Cover with PCV Valve, Gasket and Bolts for 2.5 Jetta Rabbit Golf Passat 2006-2014 : Automotive

Buy Genuine OEM Volkswagen Valve Cover with PCV Valve, Gasket and Bolts for 2.5 Jetta Rabbit Golf Passat 2006-2014: Valve Cover Gasket Sets - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

When my gasket failed, the interior one dripped oil on top of the coils and plugs.