Audi Workshop Service and Repair Manuals

Notes:

• ◆ Cylinder heads with cracks between valve seats can still be used without a reduction of service life, if cracks are slight, max. 0.5 mm wide.
• ◆ When fitting a new cylinder head or cylinder head gasket, drain off all the old coolant and re-fill with new coolant.
• ◆ The cylinder head on a diesel engine must not be reworked.
• ◆ When installing an exchange cylinder head with fitted camshaft, the contact surfaces between tappets and cams must be oiled after installing the head.
• ◆ The plastic protectors fitted to protect the open valves must only be removed immediately before fitting the cylinder head.
• ◆ Note current specifications when using sealant:

=> Parts List

• cylinder head
• ◆ Removing
• ◆ Check for distortion => Fig.1
• ◆ Installing
• ◆ After replacing, fill with fresh coolant
• 25 Nm
• Lifting eye
• Sealing cone, bottom
• Cylinder head cover gasket
• ◆ Renew if damaged or leaking
• ◆ Before fitting gasket apply D454 300 A2 at sealing points => Fig.3 and Fig.4
• ◆ Insert lugs in holes on cylinder head

• Cylinder head cover
• ◆ Removing and installing
  => Page 15-8
• Sealing washer, top
• ◆ Replace, if damaged
• Plate washer
• 10 Nm
• Trim cap
• Gasket
• ◆ Renew if damaged or leaking
• Cap
• Breather hose
• Hose clamp
• ◆ Connect with hose to retainer tab of cylinder head cover

• Pressure regulating valve
• ◆ For crankcase breather
• Gasket
• ◆ Replace, if damaged
• Cylinder head bolt
• ◆ Replace
• ◆ Note sequence when loosening => Page 15-26
• ◆ Note sequence when tightening => Page 15-30
• Injector pipes
• ◆ Tighten to 25 Nm
• ◆ Remove with 3035
• ◆ Always remove pipework complete
• ◆ Do not alter shape
• 10 Nm

• Coolant flange
• ◆ With coolant temperature sender
• O-ring
• ◆ Replace
• Coolant flange
• 10 Nm
• Connector
• ◆ For needle lift sender -G80
• Return pipe
• ◆ To injection pump
• Cylinder head gasket
• ◆ Renew => Removing cylinder head, Page 15-14.
• ◆ Observe marking
  =>Fig.2
• ◆ After replacing, fill with fresh coolant

→ Fig.1    Check cylinder head for distortion.

• ‒ Use knife edge, straightedge and feeler gauge to measure at several points.
• ‒ Max. permissible distortion: 0.1 mm

Note:

The cylinder head on a diesel engine must not be reworked.

→ Fig.2    Cylinder head gasket identification

• ◆ Part no. = arrow 1
• ◆ Holes = arrow 2
• ◆ Production control code = arrow 3 (can be disregarded!)

Note:

Cylinder head gaskets of different thickness are fitted depending on the amount of piston projection => Page 13-96. When replacing just cylinder head gasket, new gasket should be same size as old one.

→ Fig.3    Seal connections between bearing cap and cylinder head

• ‒ Carefully apply a small amount of sealant "D 454 A2" to both sides of sealing surfaces between bearing cap and cylinder head -arrows- using a small screwdriver.

→ Fig.4    Seal connections

• ‒ Carefully apply a small amount of sealant "D 454 300 A2" to both sides of sealing surfaces -arrows- using a small screwdriver.