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Complaint
The engine makes ticking/crackling noises at idle speed and at speeds up to approx. 1500 rpm.
Notes:
The noise occurs after driven distances as of approx. 20,000 km or after an oil change.
Noise is clearly noticeable in area of 1st crankshaft main bearing.
Noise can no longer be heard when the poly-V belt is removed for diagnostic purposes.
The complaint noise must in all cases be compared with the example noise.
The noise is not regular. Pulse-like crackling noises occur at irregular intervals; compare with example noise.
20 pulses (ticking) for which complaints are justified can be heard in the attached noise example.
File
Designation
Tickern OM642_neu.mp3 [N/A] Crackling noise, isolated ticking/crackling
Cause
Run-in effect of 1st crankshaft main bearing.
Remedy
Check procedure:
1. Remove/install poly-V belt (AR13.22-P-1202GZB)
Note: Use the operation number G13-1202.
Note:
If the ticking noise can still be heard after removal of the poly-V belt, MSB 1 is not the cause of the defect.
If the ticking noise can longer be heard after removal of the poly-V belt, there is a defect at MSB 1. The crankshaft bearing shell of the 1st crankshaft main bearing must be changed.
Repair scope:
Replacement of crankshaft bearing shells of 1st crankshaft main bearing
Note:
It is important to ensure that only the new/lead-free bearing shells are used.
Always check that the part number is XXXXX before unpacking the components - no object number is XXXXX on the component.
The old and new bearing shells differ in appearance. Pictures showing these differences are provided in the attachment.
Note:
The main bearing shell has various type and tolerance classifications which are subdivided into various color codes.
The top main bearing shell of a bearing can have a different color code to the bottom main bearing shell.
It is important to select the correct main bearing shell for the specific position - in accordance with the defined specifications.
Here the following applies for the positioning of the bearings:
The bearing class information runs from left (1st main bearing) to right (2nd - 4th main bearings).
Meaning of color codes (color index):
G = yellow (54), R = red (56), B = blue (52), W = white (57), V = violet (58)
The specification on the following components is used for determining the tolerance classification (see bearing classification in the attachment):
- the cylinder crankcase - for the top bearing shell
- the front crankshaft stub - for the bottom bearing shell The vibration damper must be removed so that the information on the crankshaft is visible.
Procedure for replacement of bearing shells of 1st crankshaft main bearing:
Remove oil pump
Model series 164 + 251: AR18.10-P-6020GZB
Model series 211: AR18.10-P-6020TI
Model series 219: AR18.10-P-6020T
Model series 203 + 209: AR18.10-P-6020PI
Model series 204: AR18.10-P-6020CO
Model series 221: AR18.10-P-6020SXI
Model series 461 + 463: AR18.10-P-6020GY
Loosen AC compressor
Note: Removal of the AC compressor is not necessary. Then tighten again to following torques:
BA83.55-P-1000-01R: Bolt, refrigerant compressor to timing case and left engine support - 20 Nm. The connected lines must be tied back when doing so.
Loosen crankshaft bearing cap of 1st main bearing and remove
Model series 164 + 251: AR03.20-P-4351GZB
Model series 211: AR03.20-P-4351TI
Model series 219: AR03.20-P-4351TQ
Model series 203 + 209: AR03.20-P-4351PI
Model series 204: AR03.20-P-4351CO
Model series 221: AR03.20-P-4351SXI
Model series 461 + 463: AR03.20-P-4351GY
Note: Do not remove the remaining main bearing caps. Do not loosen the chain tensioner.
Using a soft tool (plastic wedge, brass strip with approx. 4 mm wall thickness), push main bearing shell out from one side and pull it out from other side by means of holes in main bearing shell. Ensure that the crankshaft bearing surface is not damaged or scratched (see the picture of the brass strip in the attachment).
Coat new bearing shell with engine oil. Note: Ensure that the main bearing shell/guide lug is inserted correctly.
Assemble in the reverse order
Note: The operation number 02-6485 for the respective model series must be applied for the repair scope "Replacement of main bearing shells of 1st crankshaft main bearing".
Tightening torques:
Crankshaft bearing cap to crankshaft bearing bracket:
35 Nm (from inside to outside)
2x 95° (from outside to inside)
Cross bolting (side bolt, crankshaft housing to crankshaft bearing cap):
50 Nm
1x 95°
