check engine AUDI A8 1998 D2 / 1.G AHA ATQ Engines Cylinder Block Crankshaft And Flywheel Component Service Manual

13-4


Cylinder block, crankshaft and
flywheel, servicing Notes:

Always replace seals and O-rings.
The engine speed sensor is installed in the
transmission bellhousing with a spacer washer
underneath.
1 -
Main bearing cap bolts
Always replace60 Nm (44 ft lb) + additional 180 (1/2 turn)
2 -
Main bearing caps
Always replace boltsMarking -1- on oil pump sideChecking bearing clearance page 13
-25
3 -
Connecting rod bearing bolts
Always replace30 Nm (22 ft lb) + additional 90 (1/4 turn)When measuring radial clearance, tighten
to 20 Nm (15 ft lb), but do not turn further
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13-13


- Turn crankshaft at central bolt of toothed belt gear in direction of
engine rotation to cyl. 1 TDC. Timing marks -A- and -B- must be
aligned.

WARNING!
DO NOT turn crankshaft while checking for TDC mark. Personal
injury may result. - Check position of camshafts. Large holes (arrow) of securing plates on
camshaft sprockets must face toward inside and align.
If not, turn crankshaft one revolution further.
- Remove sealing plug from left-side of cylinder block.
- Top Dead Center (TDC) mark on crankshaft must be visible or be felt
behind bore of removed sealing plug.
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13-23

Driveplate

- Hold crankshaft in position using 3242
crankshaft holder page 13
-12
.

- Mark hole pattern of driveplate, shim -1- and
washer -2- to crankshaft.

- Mark positions of shim -1- and washer -2-
(behind driveplate).

CAUTION!
Part numbers are listed here for reference only. Always check with
your Parts department for the latest information.
Notes: - Install driveplate with washer -2- (Part No. 035 105 303 A) and shim -1-
3.0 mm (Part No. 054 105 301) or 4.0 mm (Part No. 054 105 202).
Short engines and exchange engines are supplied without a bushing
in the crankshaft. Always install a new bushing before installing the
driveplate. Remove bushing using 21/1 Kukko puller and 21/2 Kukko support.Always replace driveplate mounting bolts.
Component
Tightening torque
Driveplate to crankshaft
30 Nm (22 ft lb) + 90
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13-31


Checking piston ring end gap
Engine codes AHA, ATQ - Insert ring at right angle from top and slide down into lower cylinder
opening until approx. 15 mm from lower edge of cylinder. Piston ring
End gap, new mm. (in.)
Wear limit mm.
(in.)
1
(compression) 0.35-0.50 mm (0.014-0.020
in.) 1.0 mm (0.039 in.)
2
(compression) 0.50-0.70 mm (0.020-0.028
in.) 1.4 mm (0.043 in.)
3 (oil scraper) 0.25-0.50 mm (0.010-0.020
in.) 0.8 mm (0.031 in.)
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13-32

Cylinder bore, checking


Piston and cylinder bore dimensions
Engine codes AHA, ATQ
Note:
Replacement pistons are only available in the basic dimension.
CAUTION!
DO NOT measure cylinder bore dimensions while the cylinder block
is mounted on the engine stand. The cylinder block is stressed and
deformed by its own weight under these conditions and the
measurements will not be accurate. - Measure at three locations diagonally in crosswise direction -A- and
lengthwise direction -B-.
Inner bore gauge: 50-100 mm (1.96-3.94 in.)
Deviation from nominal size: max. 0.08mm (0.0031 in.)Reconditioning
dimension Piston diameter
Cylinder bore
diameter
Basic dimension 82.48 mm (3.2472
in.) 82.51 mm (3.2484
in.)
1st oversize 82.74 mm (3.2575
in.) 82.76 mm (3.2578
in.)
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11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.GE03.13.2