Skip to Main content Skip to Navigation
Journal articles

Understanding carbonaceous deposit formation resulting from engine oil degradation

Abstract : The formation processes of carbonaceous deposits in the first piston ring grooves of direct injection diesel engines have been studied. Deposits generated during engine tests were analysed by SEM/EDX, thermogravimetric analysis, pyrolysis/gas chromatography/mass spectrometry, and FT-IR spectroscopy. These analyses showed that the deposits, with a structure of cracked varnishes, mainly resulted from the degradation of lubricants. Their state strongly depends on the severity of the tests, which resulted in the formation of two kinds of deposits, termed as 'oily' and 'dry', according to their content of volatile organic matters. Then, to better understand the deposit formation process, a thermo-oxidative degradation of the lubricating oil was carried out in a tubular furnace, while varying temperature, duration of the test, and adding metallic elements to simulate the engine wear. The consumption of antioxidant additives and the lubricant carbonization were highlighted. Temperature level was identified as the most influential parameter during the lubricant degradation process. The presence of metallic elements appeared to act as a catalyst by speeding up the degradation when the tests duration was increased. Cop. 2008 Elsevier Ltd. All rights reserved.
Document type :
Journal articles
Complete list of metadatas
Contributor : Denis Roura <>
Submitted on : Thursday, November 21, 2013 - 2:50:55 PM
Last modification on : Thursday, March 5, 2020 - 6:18:48 PM




Moussa Diaby, Michel Sablier, A. Le Negrate, M. El Fassi, J. Bocquet. Understanding carbonaceous deposit formation resulting from engine oil degradation. Carbon, Elsevier, 2009, 47 (2), pp.355. ⟨10.1016/j.carbon.2008.10.014⟩. ⟨hal-00904654⟩



Record views