Engine - Poor Performance/Hissing Noise/High Fuel Trim
24 08 722010064/3
November 24, 2008. Supersedes Technical Service Bulletin Group 24 number 05-04 dated July 21, 2005 for reasons listed below.
Vehicle Information
24 Engine, Intake Manifold Mounting Bolt Torque
Condition
24-05-04, July 21, 2005
Engine, Intake Manifold Mounting Bolt Torque
Supersedes 24-04-02, July 6, 2004
Technical Background
Intake manifold bolts could loosen. This condition may cause erratic engine operation, poor performance and/or hissing noise from engine and high fuel trim readings in MVB 32.
Production Solution
Service
Inspection
- Remove front engine cover -arrow-.
Check for Red paint dot next to engine code sticker.
S4, S4 Cabriolet and allroad shown.
If intake manifold has Red paint dot:
- No action required. Do Not complete this Technical Bulletin.
If intake manifold does not have Red paint dot:
- Continue with this Technical Bulletin.
Check for Red paint dot next to engine code sticker.
A6 and A8L shown.
If intake manifold has Red paint dot:
- No action required. Do Not complete this Technical Bulletin.
If intake manifold does not have Red paint dot:
- Continue with this Technical Bulletin.
Check torque of 14 intake manifold mounting bolts.
If intake manifold bolt torque is between 4-11 Nm:
- Tighten intake manifold bolts in stages and sequence shown to 11 Nm.
- Run engine for 10 minutes.
- Retighten intake manifold bolts in stages and sequence shown to 11 Nm.
If intake manifold bolt torque is less than 4 Nm:
- Remove intake manifold.
- Check intake manifold sealing surface for distortion.
If distortion is below 0.10 mm
- Install new intake manifold gaskets (Part No: 077 129 717Q).
- Reinstall intake manifold and tighten bolts in stages and sequence shown in illustration 15-A073 to 11 Nm.
- Run engine for 10 minutes.
- Retighten intake manifold bolts in stages and sequence shown in illustration 15-A073 to 11 Nm.
Tip: Part numbers listed in this bulletin are for reference only. Always check with your Parts Dept. for the latest parts information.
If Distortion is between 0.10 mm to 0.40 mm
- Install new manifold gaskets Part No. 077 129 717Q and apply sealant (Loctite 5970) Part No: D 176 501 A1 (see TIP below) as follows:
Tip:
Intake manifold must be installed and tightened to proper torque within 10 minutes of application of the sealant.
- Apply a 2 mm wide continuous bead of sealant around entire periphery of each intake port of cylinder heads (see dotted lines) prior to gasket installation.
- Immediately install new gaskets to cylinder heads (ensure gaskets are installed over metal alignment pins numbered 1).
- Secure gaskets to cylinder heads using threaded plastic alignment pins (pins numbered 2).
- Apply a 2 mm wide continuous bead of sealant around entire periphery of each intake port of the secured intake gaskets (see dotted lines).
- Tighten intake manifold bolts in stages and sequence shown in illustration 15-A073 to 11 Nm.
Tip:
After tightening manifold bolts to proper torque, the sealant needs to set up for one hour prior to starting the engine.
- After the sealant has set up, run engine for 10 minutes.
- Retighten intake manifold bolts in stages and sequence shown in illustration 15-A073 to 11 Nm.
On All Engines
After tightening intake manifold bolts to the proper torque, place a Red paint dot next to engine code sticker as shown in appropriate inspection illustration.
Warranty
Required Parts and Tools
- Manifold Gaskets Part No. 077 129 717Q
- Sealant (Loctite 5970) Part No: D 176 501 A1
Part numbers listed in this bulletin are for reference only. Always check with your Parts Dept. for the latest parts information.