Cleaning the Plenum

[msmithmmx]

I am finishing up the HG on my 2.5. I was ready to put the air intake and wireharnes back on top and decided to pull off the throttle body. Glad I did it was nasty, not surprised it has 200K. How would one clean the inside of the air intake manifold? It is very very gunked up. I guess I could spray engine degreaser in there and let it drip out. Anyone do this before?

[GeneralDisorder]

I work with Zep products all day so I know them best - I would probably start with a citrus based degreaser like Big Orange, and after that soaks in I would spray it all out with an evaporating degreaser like ID-Red or Aerosolve. Similar products can be found at the local autozone or the like I'm sure.

 

GD

[Strakes]

I've used CRC's Air intake cleaner, and it worked well:

 

http://www.shipstore.com/SS/HTML/CRC/CRC05078.html

 

I don't know if our Subarus are like this, but some intakes have a special coating from the factory that you don't want to "clean" off with a very aggressive cleaner.

[Gnuman]

I've used CRC's Air intake cleaner, and it worked well:

 

http://www.shipstore.com/SS/HTML/CRC/CRC05078.html

 

I don't know if our Subarus are like this, but some intakes have a special coating from the factory that you don't want to "clean" off with a very aggressive cleaner.

 

Yes, but he said that he pulled off the throttle body, where that coating lives. Also be sure that you replace the gasket that goes between the throttle body and the plenum. You don't to have introduced an air leak, do you?