Lubricants for Underhood Applications

New and emerging environmental regulations require engineers to design internal combustion engines that comply with strict emission standards without sacrificing performance. As a result, OEM’s require engine controls to ensure that both emission and performance requirements are met. Even hybrid vehicles with smaller engines need engine controls to achieve desired performance levels. Flex-fuel vehicles also need engine controls to maintain performance with changing fuel mixes. Actuators, pumps, and valves require lubricants to improve the reliability and extend the life of engine controls. Lubricants for these applications must be carefully selected to withstand the demanding underhood conditions

Which Factors Can Impact the Performance of Underhood Lubricants?

Chemical Exposure

Lubricants for on-engine applications must be able to withstand the harsh chemicals, fuels, and exhaust present underhood. Perfluoropolyether's (PFPEs) thickened with Polytetrafluoroethylene (PTFE) are recommended for these applications as they are inherently chemically inert and unaffected by corrosive gases and liquids.

Extreme Temperatures

Internal combustion engines are designed to run hot. Lubricants for these applications should be stable at high temperatures to prevent varnishing and breakdown. The ideal lubricant should also remain fluid at low temperatures to provide sufficient lubrication and ensure that engine controls work properly during cold starts.

Fretting Corrosion

Fretting corrosion is the result of micromotion caused by vibration and/or thermal expansion due to heating or cooling cycles. In electrical connector applications, these micromovements wear down through the metal coatings into the base material and promote oxidation. The formation of this oxide layer can result in power failure or signal loss. In bearings, fretting can prematurely wear the raceway in the form of hollow dents, also known as false brinelling. In both cases, oxides can lead to premature failure.

Particle Size

Any particle that acts like a “speed bump” in the motion of the bearing, no matter how small and subtle, is a source of early failure. These bumps translate into vibration and ultimately wear and noise, so removing the particles is particularly important in precision bearings and instruments. For these reasons, a smooth grease with fewer particles may be required in certain underhood applications.

Which Underhood Applications Require Lubrication?

Lubricants are required to protect connectors, gears, and bearings to extend the life of engine controls and improve performance.

Actuators

Diesel Engine Smart Remote Actuator
EGR Actuators, Turbocharger Actuator
Motorcycle EGR Actuator
Throttle Body Actuator

Pumps

Fuel Pumps
Water Pumps
Hydraulic Pumps

Valves

EGR Valve
Idle Air Control Valve
Coolant/Thermostat Valves