I have been chasing this for months, dating back to when I bought a MAF sensor because I got my check engine light with the code P170 (intake fuel trim something). I changed the MAF sensor, no luck!
I kept checking as recommended for a vacuum leak. I found this leak by running the car at idle and spraying MAS spray cleaner around the intake track, near the identified location, the spray effected the idle--bingo! I applied some extra torque to these bolts and the leak went away for about a month---but now it's back!
Needless to say I need to change this gasket, but I contacted my long time MB dealer and they said that the intake manifold is not “serviceable” here—in other words the intake manifold is sold as an assembly, so the gasket and torques specs are not available! They say I have to buy the entire intake manifold---big bucks!
Help, has anyone come across this same problem on the 320 motor? How have you guys solved this? I can’t believe anyone that is mechanically inclined would buy an entire manifold to solve this leak.
Thanks for any help!!!

 

ive never had the 2 pieces apart and it may not be serviceable due to the tumble flaps that are in there. there flaps that change that airflow inside between short and long runners...but if you can get it apart i would seal it with RTV black sealant. Ill try and get some info at work tomorrow