Glossary of Terms

Industry Jargon Buster

Welcome to Essex Turbos Glossary of Terms Page. This page’s content has been compiled to help explain some of the current turbocharger industry jargon. Every industry is guilty of using acronyms, descriptions and terms in conversation that can leave the customer feeling none the wiser to what has just been discussed!!! And turbo suppliers, garages, car dealers are no exception.

Turbo / Turbocharger

Turbo is a shortened version for Turbocharger. They are the same part fitted to the vehicle engine.

Reman turbo
Remanufactured turbo / remanufacture turbo. Refers to an aftermarket turbo that has been completely rebuilt. i.e. rebuilt turbo or turbo rebuild
Recon turbo

Reconditioned turbo / recondition turbo. A phrase used to describe an aftermarket turbo that has had some work completed on it. The phrase is often used to mean the same as a reman turbo (remanufactured turbo).

It refers to the work done to only the part of the turbo assumed to be the problem. Often we are told “it’s only the bearings that have gone in the turbo” or “it’s only my seals that have gone in the turbo”. More often than not there are other issues needing attention and the price may well change to reflect that!!
Exchange turbo

Refers to the type of sale made and the requirement that the old failed turbo taken off the vehicle forms part of the sale and is required back.

Old Unit

Refers to the failed turbo taken off the vehicle.


This stands for Original Equipment Manufacturer and is sometimes referred to as the OE number. i.e. vehicle manufacturer’s such as Audi, BMW, Ford etc. this is often seen in connection with a turbo part number to identify the turbo fitted to the vehicle. The OEM part number is issued by the vehicle manufacturer.


This is one of the original big turbo manufacturers. Started in 1936 by Cliff Garrett it has evolved through names such as AiResearch, AlliedSignal, to the Honeywell of today.


This is one of the original big turbo manufacturers. In 1899 the joint-stock company of Kühnle, Kopp & Kausch (KKK) was established in Germany. In 1952 turbocharger development and production started at AG KKK in Germany.

Borg Warner Turbo Systems

In 1928 Borg-Warner Corporation was formed. Founding companies include Borg & Beck, Marvel-Schebler, Warner Gear and Mechanics Universal Joint. In 1997 BorgWarner Automotive acquired a majority stake in AG Kuhnle, Kopp & Kausch (KKK). In 1999 BorgWarner bought Schwitzer and along with 3K-Warner integrate them in BorgWarner Turbo Systems.


In 1998 3K-Warner Turbosystems GmbH was formed as a BorgWarner subsidiary, after the acuquisition of the supercharging systems division of AG Kuhnle, Kopp & Kausch (KKK)


Japanese owned turbo manufacturer. In 1960 Ishikawajima Heavy Industries Co. Ltd and Harima Shipbuilding & Engineering Co. Ltd merge to establish Ishikawajima-Harima Heavy Industries Co. Ltd (IHI)


The trademark stands for Variable Nozzle Turbine. It’s a technology developed to improve the performance of small diesel engines at low RPM incorporating a variable vane assembly. (This is Honeywell Garrett’s version)


The trademark stands for Variable Turbine Geometry. It’s a technology developed to improve the performance of small diesel engines at low RPM incorporating a variable vane assembly. (This is Borg Warner’s version)

Variable Vane Assembly

This is the set of steel shaped ‘fins / blades’ that open and close to control the amount of exhaust gases flowing around the Turbine Housing (Exhaust side of the turbo). This assembly forms part of what people refer to as a ‘VNT Turbo’ or Variable Vane Turbo’.

Carbon build-up

Refers to the sooty deposits left behind in the exhaust side of the turbo from excessively sooty exhaust gases.

Sticky Vanes

The phrase used to describe the effect sooty exhaust gases have when passing through the exhaust side of the turbo and leaving carbon deposits (carbon build-up) around the variable vane assembly. This restriction can cause the turbo to drop into a ‘limp mode’ (limp home mode) due to boost issues. The first thing the driver can experience is the ‘glow plug light’ coming on.

Limp Mode

The vast majority of modern vehicles have an engine management system which is controlled by an ECU (onboard computer). If the vehicle experiences a senor or equipment failure the ECU gets to know. When it detects that something semi-serious is wrong, it enters the limp mode i.e. survival mode, which means that the engine won’t rev beyond a pre-programmed speed. The vehicle goes into limp mode so that the driver can get the damaged vehicle to the next town for repairs. This condition is commonly called ‘limp home mode ‘ because rather than being stranded, you’re able to limp to the next town in either second or third gear

MAP Sensor

The Manifold Absolute Pressure (MAP) sensor is used to monitor intake manifold pressure (engine load). The engine ECU then uses this information to adjust ignition timing and fuel enrichment.

MAF Sensor

Mass AirFlow sensor (MAF) measure the volume and density of the air entering the engine so the computer (ECU) can calculate how much fuel is needed to maintain the correct fuel mixture. The sensing element in MAF sensors can be easily contaminated. An engine with a bad MAF sensor may start and stall or be hard to start. It may hesitate under load, idle rough or run excessively rich or lean. The engine may also hiccup when the throttle suddenly changes position.

EGR Valver

The EGR valve or Exhaust Gas Recirculation valve, is a vacuum controlled valve which allows a specific amount of exhaust back into the intake manifold. This exhaust mixes with the intake air and actually cools the combustion process. Cooler is always better inside the engine. The exhaust the EGR valve recirculates also prevents the formation of Nitrogen related gases. These are referred to as NOX emissions, and are a common cause for failing emissions testing. Unfortunately, the EGR valve can get stuck, causing NOX gases to build up. If the EGR valve is stuck or malfunctioning the car will experience symptoms like rough idle and bucking on acceleration.


A component attached to the turbocharger to help control the turbo boost levels. It is sometimes mistakenly referred to as the ‘turbo activator’.

Pressure Actuator

This refers to the type of actuator used on the turbo. You’ll probably hear the term ‘Pressure controlled turbo’.


This refers to the type of actuator used on the turbo. You’ll probably hear the term ‘vacuum controlled turbo’.

Electronic Actuator

This refers to the type of actuator used on the turbo. You’ll probably hear the term ‘Electronically controlled turbo’. This is the latest generation of actuators used in turbocharger production. BMW, Ford & Mercedes are now using alot of electronically controlled turbos. Example turbos include: BMW 320d turbo p/n: 49135-05671 (7795499K10), Ford Focus C-Max turbo p/n: 760774-5003S (3M5Q6K682CD) and a Mercedes E320 CDI turbo p/n: 765155-5007S (A6420900280)


This stands for Rotary Electric Actuator. This is a type of electronic actuator.


This stands for Simple Rotary Electronic Actuator. This is a type of electronic actuator.


P132B is a common electronic actuator fault code (error code) given by diagnostics machines. P132B relates to a REA fault (Rotary Electronic Actuator) which is the little black box on the side of the turbocharger. The common reason for this failure is a restriction in the movement of the electronic actuator’s arm (the electronic box) usually cuased by a carbon build-up around the variable vanes assembly inside the turbo. This restriction can then generate a fault code in the electronic actuator (the electronic actuator is sometimes referred to by customers as an ‘electronic activator’).