QuestionI have a 1999 Chrysler 300M. 3.5L It makes a loud vacuum leak sound from the back of the intake TB area. Is this a common thing???
I thought I saw this in a Chrysler TSB several years ago.
Intake leak, Throttle Body leak, etc???
AnswerNO: 14-02-99
SUBJECT: "Hiss" Noise From Engine When Idling
DATE: June 18, 1999
OVERVIEW:
This bulletin involves replacing the throttle body assembly.
NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 3.2L OR 3.5L ENGINE.
SYMPTOM/CONDITION:
"Hiss" noise similar to a vacuum leak during engine idle and/or low RPM driving conditions. The noise is most noticeable during cold engine operation from outside the vehicle, but may also be heard at normal operating temperatures and/or from inside the vehicle.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS/MDS2) and or the Diagnostic Scan Tool (DRB III®) with the appropriate Diagnostic Procedures Manual, verify all engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin. If no DTC's are present, check all engine vacuum lines, connections, and air induction tubes including the air cleaner and air cleaner filter box to assure that no restrictions, vacuum or air leaks exist. Verify that the EGR tube and seals are properly seated. Check throttle body gasket seating and for cracks/splits or missing material. If no problems are found and the noise is still present, perform the Repair Procedure.
PARTS REQUIRED:
Qty Part No. Description
1 04591168AC Throttle Body, LH Vehicles
1 04865278AB Throttle Body, PR Vehicles
REPAIR PROCEDURE:
THIS REPAIR IS COMPATIBLE WITH DAIMLERCHRYSLER'S MOBILE SERVICE PROGRAM AND DOES NOT REQUIRE HOISTS OR OTHER FULL SERVICE FACILITY SPECIAL EQUIPMENT.
Disconnect and isolate the negative battery cable remote terminal.
Remove wiper arms (LH only).
Remove cowl screen (LH only).
Remove cowl plenum (LH only).
Disconnect air plenum from throttle body.
Remove throttle cable.
Disconnect electrical connectors.
Disconnect top vacuum hose.
Remove 3 throttle body bolts.
Remove throttle body support bracket bolt (LH only).
Remove throttle body assembly.
Hold throttle lever in the wide open position. Remove throttle cable and speed control cable from throttle arm.
Clean mating surfaces.
Hold throttle lever on new throttle body in wide open position. Install throttle cable and speed control cable.
Install throttle body. Tighten bolts to 12 Nm (105 in. lbs.).
Tighten throttle body support bracket bolt to 27 Nm (240 in. lbs.) (LH only).
Install purge vacuum hose.
Install throttle cable bracket.
Install air plenum.
Install cowl plenum (LH only).
Install cowl screen (LH only).
Install wiper arms (LH only).
Connect negative battery cable to remote terminal
