STi intercooler install on a Subaru WRX

9. Install the mounting bolts and re-bolt the metal tube to the front of the intercooler. Replace the bypass valve with the new gasket and bolt it to the intercooler.

Be sure to use a new gasket when reinstalling your bypass valve, or you’ll get a pressure leak.
Be sure to use a new gasket when reinstalling your bypass valve, or you’ll get a pressure leak.
Reattach the metal tubes to the new intercooler.
Reattach the metal tubes to the new intercooler.
Tighten down the main bolts and you’re done.
Tighten down the main bolts and you’re done.

10. Your finished installation should fit snugly under the hood, and you should hear no pressure leaks from the pipes. You can spray a little Windex on the tube joints to check for bubbles when the car is running. Your new intercooler should clear the air conditioning lines without touching. And you get the snappy STI logo to please your eye and impress your friends every time you open the hood.

Check for pressure leaks by spraying a bit of Windex around the joints with the engine running and a little bit of boost built up. You’ll see bubbles if there’s a problem.
Check for pressure leaks by spraying a bit of Windex around the joints with the engine running and a little bit of boost built up. You’ll see bubbles if there’s a problem.