Operating instructions

7.2 Cylinder Liner
7.2.1 Endoscopically examining cylinder liner
Preconditions
☑Engine shut down and secured against being restarted.
Special tools, Material, Spare parts
Designation / Use Part No. Qty.
Cranking tool
F6555766 1
Ratchet with extension
F30006212 1
Endoscope
Y20097353 1
Preparatory steps
1. Remove cylinder head cover (→ Page 74).
2. Remove injector (→ Page 78).
Positioning crankshaft at BDC
1. Using cranking tool, turn crankshaft until crankpin of the cylinder to be tested has reached BDC.
2. Insert endoscope into cylinder liner through injector socket.
Endoscopically examining cylinder liner
Findings Action
•
Thin carbon coating around carbon scraper ring
•
Slight localized additive deposits at top edge
•
Localized polished areas at bottom edge
•
Ring of carbon around entire circumference between top piston ring
and bottom edge of carbon scraper ring
•
First signs of marks left by top piston ring
•
Light traces around circumference
•
Faultless, even honing pattern
•
First signs of marks left by lower cooling bores
•
Wear pattern appears darker
No action required.
•
Dark areas with even or varying degrees of discoloration
•
Beginning and end of the discoloration are not sharply defined and
do not cover the entire stroke length
•
Dark areas in the upper section of the cooling bore, remaining cir-
cumference cannot be faulted
•
Piston rings cannot be faulted
Further endoscopic examina-
tion required as part of mainte-
nance work.
•
Around the entire circumference, as well as areas of pale discolora-
tion (not such as to impair operation) clearly darker stripes that
start at the top piston ring
•
Heat discoloration in the direction of stroke and honing pattern
damage
•
Heat discoloration of piston rings
Cylinder liner must be replaced;
contact Service
M015675/06E 2013-04 | Task Description | 55
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