Sealing upper and lower covers — VW
Sealing upper and lower covers on VW: factory workshop procedure for engines BCA, BGU, BSE, BSF. Full factory text, tools and checks.
Workshop procedure for VW — the factory write-up, straight from real workshop data.
📋 Procedure
ℹ️ Torque figures below come verbatim from workshop data — always cross-check against your vehicle's factory manual before final tightening.
Sealing upper and lower covers
Special tools and workshop equipment required
Silicone adhesive sealant
D 176 501 A1
Loctite 242
Loctite 222
Loctite 7063
Removing fuel tank (Autogas)
Chapter
.
Sealing lower cover:
Removing and installing lower cover
Chapter
.
Clamp lower cover in a holding device.
Note
Thoroughly clean O-ring grooves, bolts, blind holes and and contact surfaces using
Loctite 7063
.
Thoroughly clean threads and blind holes with compressed air.
Wear gloves and ensure items are free of grease.
Bead thickness: at least 2.5 mm
Application life of silicone sealant, max 15 minutes.
Thoroughly clean sealing surfaces using
Loctite 7063
.
Note
Sealing surfaces must be grease-free.
Apply
silicone adhesive sealant
D 176 501 A1
to clean sealing surface
arrows
of lower cover
1
.
Fit suitable O-ring in groove and press in evenly. Now, apply a bead of approx. 2.5 mm
silicone adhesive sealant
D 176 501 A1
over fitted O-ring.
WARNING
Apply locking fluid to threads in blind holes (down to bottom of threaded hole).
Locking fluid must not be applied to threads of bolts, this can cause an air lock at the bottom of the threaded hole and the locking fluid will not harden.
Do not apply locking fluid to O-ring sealing seat, otherwise the sealing capability of the O-ring is destroyed.
Squirt
Loctite 242
into all 4 blind bolt holes
top arrows
and
Loctite 222
into blind washer holes
bottom arrows
.
Fit lower cover on gas tank, and tighten M6 bolts.
Tighten M4 washer bolts.
Carry out leakage test
Chapter
.
Sealing upper cover:
Removing and installing upper cover
Chapter
.
Clamp upper cover in a holding device.
Note
Always renew upper cover.
Thoroughly clean O-ring grooves, bolts, blind holes and and contact surfaces using
Loctite 7063
.
Thoroughly clean threads and blind holes with compressed air.
Wear gloves and ensure items are free of grease.
Bead thickness: at least 2.5 mm
Application life of silicone sealant, max 15 minutes.
Thoroughly clean sealing surfaces using
Loctite 7063
.
Apply
silicone adhesive sealant
D 176 501 A1
uniformly to clean O-ring groove
arrows
.
Fit suitable O-ring in groove and press in evenly. Now, apply a bead of approx. 2.5 mm
silicone adhesive sealant
D 176 501 A1
over fitted O-ring.
WARNING
Apply locking fluid to threads in blind holes (down to bottom of threaded hole).
Locking fluid must not be applied to threads of bolts, this can cause an air lock at the bottom of the threaded hole and the locking fluid will not harden.
Do not apply locking fluid to O-ring sealing seat, otherwise the sealing capability of the O-ring is destroyed.
Reinstall cover, and tighten M6 bolts.
Carry out a gas system test (GAP) once installation is complete
Maintenance
Booklet
39
.
Specified torque
Component
Specified torque
M6 bolts for upper cover
7 Nm
M6 bolts for lower cover
7 Nm
M4 bolts for washers
1.8 Nm
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
Ask about my car →Other VW procedures
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- Removing and installing fuel tank
- Removing and installing engine control unit · 3 torque figures
- Checking valve timing · 2 torque figures
- Removing and installing oil sump · 2 torque figures
- Removing engine · 41 torque figures
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- Adjusting valve timing · 83 torque figures
- Removing and installing camshafts · 39 torque figures
- Removing and installing coolant pump · 53 torque figures
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.