CEN/TR 16680:2014

SLOVENSKI STANDARD
01-maj-2014
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Liquid petroleum products - Investigation on internal diesel injector sticking deposits
mechanisms and the impacts of corrosion inhibitors
Flüssige Mineralöl-Erzeugnisse - Untersuchung der Mechanismen der interne Diesel
Injektor klebrige Deposite und der Einflüssen von Korrosionsinhibitoren
Produits pétroliers liquides - Récherche des mechanisms des deposits en injecteurs
internes du gazole ét des impacts des inhibteurs corrosives
Ta slovenski standard je istoveten z: CEN/TR 16680:2014
ICS:
75.160.20 7HNRþDJRULYD Liquid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 16680
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
February 2014
ICS 75.160.20
English Version
Liquid petroleum products - Investigation on internal diesel
injector sticking deposits mechanisms and the impacts of
corrosion inhibitors
Flüssige Mineralölerzeugnisse - Untersuchung der
Mechanismen für die Bildung von Ablagerungen in
Dieselinjektionsvorrichtungen und der Auswirkung von
Korrosionsinhibitoren
This Technical Report was approved by CEN on 23 December 2013. It has been drawn up by the Technical Committee CEN/TC 19.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 16680:2014 E
worldwide for CEN national Members.

Contents page
Foreword . 3
1 Scope . 4
2 Normative references . 4
3 Symbols and abbreviations . 4
4 Summary . 5
5 Description of injector sticking problems . 5
6 FIEM/OEM experience . 6
7 Changes influencing internal injector deposits . 7
8 Deposit forming mechanism . 7
9 Potential sources of sodium in diesel fuel . 8
10 Corrosion inhibitors . 9
11 Investigations in France . 9
12 Investigations in Spain . 12
13 Investigations in Denmark . 14
14 Conclusions . 15
15 Future work . 16
Bibliography . 17

Foreword
This document (CEN/TR 16680:2014) has been prepared by Technical Committee CEN/TC 19 “Gaseous and liquid
fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of which is held
by NEN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.
CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
1 Scope
This Technical Report describes the investigation into diesel vehicle common rail fuel injector sticking problems in a
number of countries across Europe since 2005/2006, carried out by the CEN/TC 19/WG 24/IDID Task Force. It
provides conclusions following this work that have been adopted by CEN.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for
its application. For dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
EN 590, Automotive fuels - Diesel - Requirements and test methods
3 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
Abbreviation Meaning
AGQM Arbeitsgemeinschaft Qualitatsmanagement Biodiesel
ACEA Association des Constructeurs Européens d'Automobiles (European Automobile
Manufacturers' Association)
BNPe Bureau de Normalization au service des metiers du Petrole
B7 7 % (V/V) blend of biodiesel (FAME) with diesel fuel meeting the requirements of EN 590
B30 30 % (V/V) blend of biodiesel (FAME) with diesel fuel meeting the requirements of EN 590
CEC Coordinating European Council
CEN Comité Européen de Normalization (European Committee for Standardization)
CONCAWE CONservation of Clean Air and Water in Europe
CRC Coordinating Research Council
DDSA Dodecenyls Succinic Acid
EN European Norm
FAME Fatty Acid Methyl Ester
FIEM Fuel Injection Equipment Manufacturer
FTIR Fourier Transform Infra-Red
HDSA Hexadecenyl Succinic Acid
ICP-AES Inductively Coupled Plasma Atomic Emission Spectroscopy
ICP-OES Inductively Coupled Plasma Optical Emission Spectroscopy
ICP-MS Inductively Coupled Plasma Mass Spectroscopy
IDID Internal Diesel Injector Deposits
MIL Malfunction Indicator Light
Na Sodium
OEM Original Equipment Manufacturer
SPMR Societe du Pipeline Mediterranee Rhone
TRAPIL Societe Des Transports Petroliers Par Pipeline
UFIP Union Francaise des Industries Petrolieres
Abbreviation Meaning
WDXRF Wavelength-Dispersive X-Ray Fluorescence
WG Working Group
4 Summary
At the CEN/TC 19/WG 24, Distillate fuels, meeting on 24 May 2011 in Krakow, Poland there were strong technical
representations from the Vehicle Manufacturers (ACEA) and Fuel Injection Equipment suppliers describing serious
vehicle fuel injector sticking problems in a number of countries across Europe since 2005/2006. The worst affected
country was France although sporadic problems had been reported in Denmark, Germany and Spain in recent
years.
As a result of these diesel vehicle common rail injector sticking field problems WG 24 recommended and
CEN/TC 19 endorsed the formation of an ad hoc task force under the leadership of the WG 24 convenor to urgently
investigate the injector sticking issue and provide feedback to WG 24 on a monthly basis.
5 Description of injector sticking problems
Traditional external “coking” deposits form inside and around nozzle fuel flow holes on the outside tip of injector
and are caused by combustion heat and gases, interacting with diesel fuel and engine lubricant components.
These deposits can affect the fuel spray pattern and volume of fuel delivered to each cylinder.
In the injector sticking case, two new types of internal injector deposits have been reported by vehicle
manufacturers and FIE manufacturers, these two new types of internal injector deposits can also be found together
(salt crystals inside a polymeric matrix), see Figure 1:
• Carboxylate soaps and salt deposits - typically soft, white/tan crystalline deposit;
• Organic amide deposits - lacquer, polymeric in nature, typically hard, tan/orange/brown deposit.
Deposits form on inner component surfaces of the injector restricting fuel flow by reducing armature lift and
affecting injection timing and fuel volume delivery by armature and injector needle sluggishness and sticking (see
also Figure 2).
Both Solenoid and Piezo actuated injectors were affected. Smaller component clearances due to increasing
injection pressure and highly sophisticated injection profiles required to meet increasingly challenging emission
targets make injection technologies more sensitive to IDID formation than previous generations of direct injectors.

Figure 1 — Types of injector deposits (courtesy PSA)
An increased rate of injector sticking cases was reported in wintertime. Fuel Injection Equipment Manufacturers
(FIEM) manufacturers believe the formation of the soaps continues all year round but that deterioration of fuel
injector performance is likely to be more apparent to vehicle drivers under cold starting and operating conditions
where deviations in precise control of the fuel injection becomes much a more perceptible phenomenon .
The IDID Task Force agreed to focus on the carboxylate soap deposits initially as these appeared to be the most
serious and independent of the Amide deposit issue which was thought to be related to performance additive
detergent (PIBSI). It should be noted however that the amide deposits contribute to the overall level of deposits
increasing the likelihood of an injector malfunction or even sticking failure.

Key
injector needle (left):- aubern and white crystalline deposits
armature/solenoid (middle and right): golden brown paste like deposit
Figure 2 —Example of caboxylate injector deposits (courtesy Daimler)
6 FIEM/OEM experience
Problems with injector sticking reported in specific geographic areas:
• France was the most affected country followed by Denmark and Spain, with occasional issues in
Germany.
• A higher number of injector sticking cases were reported in the northern part of France.
• The injector sticking issues in Denmark were however believed to be related to the use of a specific
corrosion inhibitor additive - Dodecenyl Succinic Acid (DDSA).
Prior to 2003, no injector sticking problems had been reported in France. ACEA experts reported that all OEM’s are
affected to some extent and that injector sticking failures are not just restricted to Europe as most major US
manufacturers of both on and off highway equipment applications with common rail systems have also reported
injector sticking failures. The US failures were primarily with heavy duty engines as there are relatively few light
duty diesel vehicles in the US vehicle parc. The Coordinating Research Council (CRC) Diesel Performance
Committee diesel deposits panel have formed a technical group to investigate injector sticking in cooperation with
the Engine Manufacturers Association (EMA).
In general vehicles covering higher mileages such as taxis and delivery vans are affected the most. Reported
injector sticking symptoms include:
• loss of power and acceleration
• poor idle stability
• increased diesel knock
• misfire - especially during cold condition
• difficulty in starting particularly in cold conditions
• rough running
• Malfunction Indicator Light (MIL) illuminated in some cases
• major drivability concern and in extreme cases - no engine start
• emission deterioration and non-compliance with long-term emission requirements
Problems seem to increase with higher biodiesel content but are not always restricted to biodiesel blends. However
fleets running B30 in France have not experienced any problems although this could be due to the increased
solvency of the B30 from the higher level of FAME.
Problems have also occurred under high load/high rpm conditions on engine test benches but only with EN 590
diesel fuel with a biodiesel content of at least 5 % v/v. The first indications of similar problems under real driving
conditions for passenger cars and medium/heavy duty vehicles driving more frequently at the high load/high rpm
conditions occur after a mileage of 50.000 km to 100.000 km. Injectors retrieved from field vehicles show an
accumulation of deposits over time exceeding a tolerable level, particularly when additional deposit material from
fuel contamination or by additive compatibility issues is also taken into account.
Problems were experienced with light commercial vans in France during 2010/11 timeframe, with a regional
distribution of cases (Alsace Lorraine) in western France and also cases of taxi vehicles in Denmark 2010/2011.
A large number of technical papers have been published by the industry describing research into injector sticking
and references are provided in the Bibliography of this report.
7 Changes influencing internal injector deposits
A number of changes in vehicle and fuel quality requirements are believed to be responsible for internal injector
deposits:
• More stringent Euro IV and V
...