The cylinder wall is formed by a Silitec liner: a silicon-carbide aluminium surface that is hard and conducts heat well. This material, however, does not cope well with high temperature and occasional detonation, and the cylinder wall becomes scored as a result. The maker finally switched to the Nanoslide coating precisely because of Silitec's cylinder scoring problems.
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On a damaged wall the piston ring does not seal, so oil gets into the combustion chamber: oil consumption rises and compression falls. The wear is reported from 120 000 kilometres, and it is faster the more the engine is run under high load.
The symptom is rising oil consumption and blue smoke under load. The repair involves opening up the engine, because the pistons have to come out to change the rings, and if the wall is already scored, changing the rings alone is not enough.
At a purchase the oil consumption is the measurable sign: ask how much has to be topped up between changes, and ask for a compression or leak-down test.
What to check
- Ask how much oil has to be topped up between changes
- Watch the exhaust under load: blue smoke means oil burning
- Ask for a compression or leak-down test: the wear is measurable here