If you have an aluminum intake manifold on your car, it’s time to clean it. Here’s how:

  1. Park your car in a safe place and turn off the engine.
  2. Remove the air filter and the plastic cover over the spark plugs.
  3. Disconnect the hoses from the intake manifold and let them hang down.
  4. Loosen the four bolts that hold the intake manifold to the engine block (two on each side).
  5. Lift up the intake manifold and set it aside on some newspapers or a cloth towel to catch any oil or coolant that might come out of it.
  6. Wipe down all of the surfaces inside of the intake manifold with a clean, dry cloth, being sure to get into all of the nooks and crannies. 7. Pour a small amount of solvent (such as acetone) into a spray bottle and mist each part of the intake manifold liberally with it, being sure to get into all of the crevices. 8 . Replace everything that you removed in Step 3-4, making sure that you tighten all four bolts securely before doing so: air filter, plastic cover over spark plugs, hoses from intake manifold, and Intake Manifold Assembly (IMA). 9 . Drive your car around for a while to allow any solvent residue to evaporate; then take it for a test drive to make sure that everything is working properly! ..