Category: Glossary of Car Terms

What is Neutral?

Neutral (gear). Neutral is actually not a gear. When your vehicle is in neutral, the gearbox and engine are completely disconnected. Thus, your car is able to roll freely whether the engine is on or off.

What is Natural Pollutants?

Natural pollution has been present on earth since before man appeared and continues to be a factor when discussing air pollution, although it causes only a small percentage of the overall pollution problem. It is the direct result of decaying organic matter, wind born smoke and particulates from such natural events as plain and forest…

What is MIL?

A Malfunction Indicator Lamp (MIL), commonly referred to as the Check Engine Light is an indicator of malfunction of the computerized engine management system. It is found on the instrument console of most automobiles. When the MIL is lit, the engine control unit stores a fault code related to the malfunction, which can be retrieved…

What is Owners Manual?

The owner’s manual is the booklet supplied with all cars when they are sold new. It is usually placed in the glovebox. Your owner’s manual contains information about the equipment your car has, what kinds of fluids and lubricants to use, and how to maintain your car. If you don’t have an owner’s manual, you…

What is ORVR?

On Board Refueling Vapor Recovery (ORVR). Nissan/Infiniti uses the ORVR system to recover the vapors from the gas tank. From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and…

What is NOX?

An acronym for Oxides of Nitrogen, a primary emission produced in the combustion chamber under high temperatures when nitrogen combines with oxygen. Oxides of nitrogen contribute to the formation of smog.

What is PCV?

The Positive Crankcase Ventilation (PCV) system provides effective evacuation of crankcase vapors. Fresh air from the air filter housing is supplied to the crankcase, where it is mixed with the blow-by gases and passed through the PCV valve and into the intake manifold. This mixture is then passed into the combustion chamber and burned. The…

What is Oxygen Sensor?

The oxygen sensor is part of the exhaust and emission systems. It senses the amount of air in the exhaust and adjusts the fuel system’s operation accordingly to minimize emissions while improving econmy and performance.

What is OHV?

Over Head Valve (OHV). An overhead valve engine has its camshaft in the engine block. It uses lifters, pushrods and rocker arms to open and close the valves in the cylinder head.

What is OHC?

Over Head Cam (OHC). An overhead cam engine has its camshaft in the cylinder head, above the valves and cylinders. This allows the camshaft to directly open the valves without using pushrods.