[boxfix]

I went through hours of poking around finding big vacuum leaks in the 2003 986 I bought a few months ago. Bought the car from a friend who could not get rid of the check engine light. I got a lot of advice from Dave and Jeremy at TRE Motorsports......great guys....

This is what I learned. Test the system with a vacuum gauge....temporarily put a T fitting in there. You should have 12 to 20 inches of mercury of vacuum at idle.

1. The plastic fitting into the rubber manifold that is the main source of vacuum fell out. I replaced with a brass barbed fitting from the hardware store and high temp silicon tubing from McMaster. It fell our because of gas and oil on the fitting and well it was just badly designed by Porsche.

2. from the factory the vacuum system has lots of plastic tubing with black rubber fittings. Guess what, heat and age makes them crack. I replaced everything with silicon tubing. Also used some brass barbed fittings where advisable and necessary.

3. the vacuum canister is down there on the passenger side of the engine.Looks like a big plastic can of Fosters beer with a domed top. One vacuum line going in. It is not molded in one piece, but two and glued together. Well the glue fails.....duhh.

Mine would not hold vacuum......duhh...again. Use long needle nose pliers to get the hose off and hook up a hand vacuum tester with a long vacuum line. See if it holds pressure. If not........ that is a massive leak. New won is like $22 from Parts Geeks or other sources. To remove the bad one you have to go in from the front and remove the alternator.....my bad one is still in there, and the new one is up in the corner of the engine compartment with a long silicon hose.....when or if I take out the Alternator.....I will take the old leaky one out.

After this relatively easy vacuum overhaul, I had 18 "hg in the system and all the CEL and emission monitors went away and the car passed smog.