Damage

Tips & Information

Service

Piston damages
Recognising and rectifying

„F T ro he fo m ne r P w P ra ra c ct ti ic ce e “

Piston damages

Imprint / Table of contents
1. Introduction........................................................................................4
1.1 1.2 Preface .........................................................................................4Notes on using this brochure ........................................................5

2. Quick diagnosis ..................................................................................6 3. Detailed descriptions of the different types of damages 10
3.1 3.1.0 3.1.1 3.1.2 3.1.3 3.2 3.2.0 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.3 3.3.0 3.3.1 3.3.2
Date 03.05 2. Edition Part-No. 50 003 973-02 Publishedby: © MSI Motor Service International GmbH Untere Neckarstraße D-74172 Neckarsulm Editors: Uwe Schilling Alexander Schäfer Authors: Bernd Waldhauer Uwe Schilling Simon Schnaibel Johann Szopa Technical Contributors: Andreas Bühl Jean-Pierre Brigaud Bernd Greiner Mike Knowles Karl Leitgeb Uwe Scherzer Graphical design and production: Margot Schneider Uwe Schilling Hela Werbung GmbH, Heilbronn |Germany This document must not be reprinted, duplicated or translated in full or in part without our prior written consent and without reference to the source of the material. All content including pictures and diagrams is subject to alteration. We accept no liability.

Seizure due to insufficient clearances ................................10 General information about seizures due to insufficientclearances ..10 Seizure on the piston skirt due to insufficient clearance .............11 Seizure due to insufficient clearances next to the piston pin bores (45° seizure marks)............................................12 Seizure due to insufficient clearances at the lower end of the skirt ..14 Seizure due to lack of lubrication .......................................16 General information aboutseizure due to lack of lubrication ......16 Seizure due to lack of lubrication on the piston skirt...................17 Piston skirt seizure on one side only without matching areas on the counterpressure side ..................18 Dry running damage due to lack of lubrication caused by fuel flooding............................................................... 20 Piston top land seizure on apiston from a diesel engine.............21 Seizure due to lack of lubrication caused by scuffed piston rings ....22 Seizures due to overheating..................................................24 General information on seizures due to overheating ...................24 Seizure due to overheating centered around the piston top land.25 Seizure due to overheating centered around the piston skirt......26 Damages due to abnormal combustion ................................27 General information about piston damage due to abnormal combustion ......................................................27 Removal of material by melting from the piston crown and ring zone (gasoline/petrol engine) .......................................31 Material removal/fusion due to melting on the piston crown (dieselengine).....................32 Cracks in the piston crown and piston combustion bowl (diesel engines).............................34 Ring land fractures .....................................................................36 Impact marks on the piston crown (diesel engine) ......................38 Hole in the piston crown (gasoline/petrolengine).............................................................40 Piston top land seizure due to the use of incorrect pistons (diesel engine)............................................................................42 Erosion on the piston top land and on the piston crown (gasoline/petrol engine).........................44 Piston and piston ring fractures .........................................46 General information about piston fractures...