Silicone Testing

If your Four Stroke Engine – Viscous Dampers need a Silicone Test you’ve come to the right place!


PJ Diesel engineering A/S is authorized by Metaldyne.

We offer both Silicone Testing, Metaldyne spare parts and high-quality factory-authorized service and have more than 40 years’ experience in servicing, repairing and maintaining Viscous Dampers.


Silicone Fluid Sampling

To monitor the condition of the silicone fluid during the damper life, sampling plugs are fitted into the damper cover and/or back face of the damper casing so that small samples of fluid (1 cm³) can be extracted from the damper.


The first test
The first sample should be taken after 15,000 hours of engine operation or at the first major engine service. After analyzing the fluid, PJ Diesel will advise subsequent sampling intervals via the analysis report.

Special sampling kits complete with instructions are available from PJ Diesel Engineering.

Up to 10 samples of silicone fluid can be extracted from a METALYNE damper without affecting its performance. It is not necessary to top up the fluid in the damper.

By following this sampling procedure and METALDYNE recommendations, the necessity for overhauling or replacing the damper can be anticipated.


Sample test


New silicone fluid is a clear / colourless fluid





Requires Service

Fluid dark brown or black in colour, usually with particles in the fluid. As a general rule, dampers with fluid in this condition have suffered internal mechanical damage and have restricted remaining service life.


Fluid colourless to light shades of yellow / brown, and free from particles. Usually indicates no internal damage. Fluid viscosity will determine suitability of damper for further service periods.


Emergency Condition

A damper with gelled / solidified fluid is unsuitable for service and it should be removed from service as soon as possible as it is no longer protecting the crankshaft from torsional vibration.


Silicone Fluid Analysis

From the silicone fluid analysis, the internal mechanical condition and operating efficiency of the damper can be established. METALDYNE and PJ Diesel Engineering will recommend the service period for the damper before a further sample of fluid must be taken.

Provided no internal damage has occurred, overhaul is recommended when the fluid has reduced 50% in viscosity value. At this stage, the damping efficiency will be 80%. The average operating time to reach this condition is 25,000 / 30,000 hours, but it can be influenced by engine application and loading as well as non-torsional factors associated with the engine’s environment such as vibrations induced from adjacent machinery, engine mountings, shafting systems and hull vibrations.

If the reduction in fluid viscosity is excessive, or the condition of the fluid indicates internal mechanical damage, PJ Diesel Engineering will advise the remaining safe service period before overhaul of the damper becomes absolutely necessary.

The PJ Diesel Engineering laboratory report meets all the requirements of major survey Classification Societies (such as ABS, DNV, BV, KR …) for marine propulsion and auxiliary power installations at the 5-year survey.

In PJ Diesel Engineering we focus on circular economy-based repair and service solutions based on “Waste Less – Lose Less” principle, and continuous optimization, so please contact us with specific application information and we will guide and advise accordingly.


New is not necessarily best!
A Viscous Damper with a wear and damages can in most cases be repaired at a price up to 75% less than buying a new one. It can even improve life cycles compared to new components from the manufacturer – and with even better delivery times.


Availability and fast response are key to our mutual success, and at the same time we can offer to repair parts which often would be stated as non-repairable. Common problems can most likely be repaired in our workshop and along comes always a 24-month liability for defects and shortages.


The PJ Diesel component workshop is located in Rødby, south of Copenhagen, and is specialized in the reconditioning of major engine components. We offer service, repair and maintenance of all types of Viscous Dampers and we have a team of factory trained service engineers working around the clock to service our customers.


Circular flow and Exchange Service


Imagine a shared response program unlocking the value of unused assets and saving you from stockpiling key components for urgent repairs.

Within PJ Diesel Engineering A/S you can join services with other end-users minimizing stock expenses, and at the same time maintaining full flexibility and the advantage of externalizing the risks. Through our exchange program expensive individual ownership costs and delivery time is reduced with shared acknowledged access to key components. Read more about our EXCHANGE SERVICE

Long- and short-term benefits


    • Improving service by enabling programmed maintenance and emergency response
    • Reduce dependency from shore facilities
    • Eliminate delivery time (Time required for repairs from shore)
    • Plug and play solutions
    • Risk reduction
    • Reduced operational cost
    • Elimination of expensive inventory
    • Fixed prices on exchange units - easy budget planning
    • 24 months liability for defects and shortages
    • High availability because of inventory at PJ Diesel Engineering A/S facilities
    • Not stocking expenses
    • No new unit investment
    • Full report and IMO/EAIAPP Validation
    • Repairable damages all included in SEU (Service Exchange Unit) A solution with no extra costs
    • Elevating from supplier to service partner (Trusted supplier)
    • Responsible and sustainable Supply Chain Management