Pistons - Chrome Plated Ring Sets
Group1
Number
8915
Model
928 S4/GT
Part Identifier
1319
December 15, 1989
Subject:
Chrome Plated Piston Rings
ATTENTION:
Service Manager/Service Technician
Chrome plated piston rings are installed in groove 1 (top).
From production date:
December, 1988.
Engine numbers:
81 K 00464 M28.41 928 S4 Manual Transmission
81 K 06640 M28.42 928 S4 Automatic Transmission
85 K 00061 M28.47 928 GT
In production a three piece oil scraper ring is installed. Repair sets contain a beveiled edge ring with internal spring (Figure 1 and 2).
New piston ring sets, Part Number:
928 103 906 09 100 mm standard size
928 103 906 10 100.5 mm oversize
Break-in Time:
A chrome plated piston ring surface is considerably harder than a ring surface without chrome plating. A break-in period is required before the piston ring surface takes the shape of the cylinder wall surface. Oil consumption of an engine with new piston rings can only be evaluated after the car has been driven at least 2,000 miles.
Important Repair Information
- Replace not only the piston rings, but also the pistons, in case of a complaint of "excessive oil consumption" from engines with a total operation of more than 40,000 miles.
This is necessary because of wear in the groove flanks of pistons. This wear cannot be determined with common workshop equipment and will continue to cause excessive oil consumption even after installation of new piston rings.
- Connecting rod bearing shells must always be replaced when repairing an engine, for which it is necessary to remove the connecting rods.