BMW X5: Piston With Ring And

REMOVING AND INSTALLING/REPLACING ALL PISTONS (N62TU)

Special tools required:

• 00 9 120
• 11 5 430
• 11 5 440
• 11 5 450

IMPORTANT: Re-install piston, conrod and bearing shells back in the same position and in the same installation location.

Conrods and conrod bearing caps are denoted with the same pairing letters, do not mix them up.

Necessary preliminary tasks:

• (engine removed)
• Install engine on assembly stand.
• Remove both cylinder heads.
• Removing oil pan.
• Remove oil pump.

In event of heavy oil carbon residue:

Carefully remove oil carbon residue from cylinder wall.

Fig. 161: Locating Oil Carbon Residue From Cylinder Wall

IMPORTANT: When removing and installing pistons, make sure piston cooling spray nozzles (1) are not damaged.

Fig. 162: Identifying Piston Cooling Spray Nozzles

Unscrew conrod bearing cover.

IMPORTANT: Conrods and conrod bearing caps are denoted with the same pairing letters.

Set down conrod bearing caps in order.

Fig. 163: Locating Conrod Bearing Cover

Insert special tool 11 5 440 in conrod.

Screw special tool 11 5 440 into conrod with screw (1).

Remove conrod with piston from cylinder head side.

Fig. 164: Identifying Special Tool (11 5 440) And (11 5 440)

IMPORTANT: Piston and piston pin are matched to each other.

Mixing up the components will result in engine damage.

Lever out circlip with special tool 11 4 492 in direction of arrow and press out piston pin.

Fig. 165: Identifying Special Tool (11 4 492)

If necessary, replace connecting rods.

NOTE: The conrods can also be replaced individually.

The piston pin must be able to be pressed through the liner by hand with little force and must not display any significant play.

Fig. 166: Pressing Piston Pin

Prior to installation, measure piston installation clearance: Measure piston diameter with micrometer at measuring point A from lower edge of piston and offset by 90º to piston pin axis.

Measuring point A.

Fig. 167: Measuring Piston Diameter With Micrometer

Adjust micrometer to cylinder bore of engine block. Set internal caliper on micrometer to zero. Measure bottom, center and top of cylinder bore in direction of travel and direction of engine rotation.

Diameter of cylinder bore. Piston installation clearance. Total permissible wear tolerance.

Fig. 168: Identifying Micrometer To Cylinder Bore Of Engine Block

NOTE: The pistons and conrods of cylinders 1 to 8 are identical.

IMPORTANT: The conrods of cylinder banks 1 to 4 and 5 to 8 are mounted to the pistons differently.

Cylinder bank 1 to 4

Mount conrod on piston in such a way that arrow on piston points upwards and marking on conrod points upwards.

Fig. 169: Identifying Piston Marking On Conrod Points

Cylinder bank 5 to 8

Mount conrod on piston in such a way that arrow on piston points downwards and marking on conrod points upwards.

Install conrod bearing.

Fig. 170: Identifying Piston Marking On Conrod Points

Install retaining ring.

Fig. 171: Installing Retaining Ring

Offset the contact points (1) of the piston rings by approx. 120º to each other but do not position above the piston pin boss.

NOTE: See illustration.

Illustration shows N52.

Fig. 172: Identifying Contact Points Of Piston Rings

Installation:

B40 and B48:

Insert special tools 11 5 440 in conrod.

Installation:

B40:

Prepare piston with rings with special tool 11 5 450.

Fig. 173: Identifying Special Tool (11 5 440) And (11 5 450)

B40:

Lightly coat pistons and piston rings with oil. Offset the contact points of the piston rings by approx. 120º to each other but do not position above the piston pin boss.

Slide in special tool 11 5 450 with piston (1).

Install piston so that arrow points to camshaft drive.

IMPORTANT: Danger of piston ring failure.

Press in piston with finger force only.

Fig. 174: Identifying Special Tool (11 5 450)

B48:

Keep piston rings compressed with special tool 11 5 430.

Install piston so that arrow points to camshaft drive.

IMPORTANT: Danger of piston ring failure.

Press in piston with finger force only.

Fig. 175: Identifying Special Tool (11 5 430)

Attach crankpin to connecting rod.

Remove special tools 11 5 450.

Fig. 176: Identifying Special Tool (11 5 440) And (11 5 440)

NOTE: For purposes of clarity, the pairing letters (1) are shown on the removed conrod.

IMPORTANT: Conrods and conrod bearing caps are denoted with the same pairing letters (1), do not mix them up.

Fig. 177: Identifying Conrods And Conrod Bearing Caps Denoted With Pairing Letters

IMPORTANT: Conrod of cylinder 1 to 4 is installed in direction of travel, see arrow (1), front.

Markings on conrod must be situated on the outside (see arrows) Incorrect assembly will result in engine damage.

Apply light coat of oil to connecting-rod bearing shells.

Fit bearing cap so that pairing letters match up.

Install new conrod bolts.

Fig. 178: Identifying Conrod Of Cylinder Of Travel

Secure conrod with special tool 00 9 120.

Tightening torque 11 24 1AZ.

Fig. 179: Identifying Special Tool (00 9 120)

Assemble engine.

REPLACING PISTON RINGS ON ALL PISTONS (N62)

(piston removed)

Measuring axial clearance of piston rings in piston ring groove (1 and 2).

NOTE: It is not possible to measure the axial clearance of the oil scraper rings.

Fig. 180: Measuring Axial Clearance Of Piston Rings In Piston Ring Groove

Remove piston rings (1 and 2) with piston ring compressing pliers.

NOTE: It might not be possible to find the identification on used piston rings.

Put aside piston rings in correct sequence and installation position.

New pistons may only be installed together with new piston rings.

Fig. 181: Removing Piston Rings

Measure end clearance.

Fig. 182: Measuring End Clearance

NOTE: Picture shows a schematic representation.

Installation:

Install piston rings with "TOP" to piston top.

1. Plain compression ring.
2. Stepped compression ring "Top".
3. Steel band ring with support spring.

Offset the contact points of the piston rings by approx. 120º to each other but do not position above the piston pin boss.

Fig. 183: Identifying Piston Rings With Top To Piston Top

Installation:

Oil control ring comprises two steel band rings (1) and a support spring (2).

Insert support spring (2) into piston ring groove.

CAUTION: Incorrect installation possible.

If the contact points overlap, the oil scraper ring will be damaged when the piston is installed.

Then fit steel band rings (1) so that contact joints are offset approx. 120º.

Fig. 184: Identifying Oil Control Ring Comprises Steel Band Rings And Support Spring

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