My 2004 CTT definitely has a vacuum leak. I get codes 2187 (about once or twice a week) and 2189 (recently started, comes on only with 2187). I haven't found the leak yet. I am hoping it's something easy. And I am hoping someone can help me track it down without just replacing everything between the MAF and the intake valves. I don't have that kind of time.
I made some videos to show the sound that the engine makes. I feel like this is probably related to the vacuum leak. Especially note the sound when I shut off the engine. It's like it takes one last breath of air after the crankshaft stops rotating.
I also mention the water pump just because it's a common point of failure on these cars and I don't want to rule it out just because the coolant level and engine running temperatures have remained stable since I replaced the leaky expansion tank and flushed the coolant about a year ago.
Here are the videos:
Front grill - YouTube - Front grill. When I move the camera down from the badge to the grill, the offending sound fades in.
Engine - YouTube - Engine, aimed at MAF. The sound is steady from this angle.
Shutdown - YouTube - Shutdown. I turned off the ignition right after the video started recording, and you can hear how the suction sound continues shortly after the engine stops.
Any clues are appreciated. I'd like to fix the leaks soon so I will have a reliable car through the winter rather than having to work on it. (Winter project is rebuilding the 964's engine, not monkeying with the Pig.
) Thanks!