Motor Mechanic Terminology to Get You Started

mechanic holding a spanner in front of a car engine

Motor mechanic terminology can mystify many people, especially those with no background in working on vehicles.

As a mechanic, however, it is a part of the job to know what all the terms mean and apply them whenever necessary.

While working as a mechanic means constantly learning new things, it’s always best to get a head start before you throw yourself into it.

Below, we’ve listed the most common mechanic terminology found in the industry which tend to cause the most confusion among customers and novices alike.

Advisory Notices

When a car comes in for an MOT inspection and it passes, this means that it goes straight back to the customer with no further action required.

However, as a mechanic, you could pass it but offer something called “advisory notices”. The third option, of course, is to fail the vehicle’s MOT.

But what are advisory notices, precisely? Essentially, they’re notes for the customer on faults with their vehicle that don’t violate safety standards.

This notice is, in essence, an essential document as it takes a record of repairs which may become necessary in future. Otherwise, the customer could fail their next MOT.

The most common items to be put on an advisory notice tend to be the general wear-and-tear components such as brakes and tyres.

It is worth noting that just because a car has passed its MOT, that does not mean it won’t need future servicing or that the customer should ignore any potential issues.

It is best to advise customers, therefore, to pay close attention to the advisory notice and get the issues fixed as soon as possible.

Brake Discs & Pads

The two main parts to any brake system are the discs and the pads. If a mechanic says, “your brake discs are warped” it means that it might need replacing entirely.

A brake disc is the primary part of the braking system that allows you to slow down. The pads clamp down onto the spinning disk when you press the brake pedal.

The friction between the two allows the vehicle to brake and due to them constantly being used, they will be one of the most commonly replaced parts.

If a brake disc becomes warped, it presents an enormous hazard as the pads won’t be able to press as firmly down on the flat surface, preventing the car from slowing.

It will need to be replaced as warped brake discs cannot be repaired. Brake pads also tend to wear down through use and will eventually need to be replaced too.

Fan Belt

In all your time as a car mechanic, you’ll come across terms which can be pretty confusing. On the one hand, the meaning of this one is in the name.

The fan belt is a belt under the bonnet that is slipping on the pulleys, which is what the mechanic means when they say, “your fan belt is slipping.”

But this is the confusing part - the fan belt has nothing to do with the fan that drives the engine. It is the belt that drives the alternator.

The alternator is basically the car’s electrical battery that allows it to power all the electrical things associated with the vehicle, such as lights.

This is why lights get dimmer when the fan belt gets loose; the power supply to the battery gets interrupted.

Many customers can diagnose this themselves and won’t seek repair services, however it is still essential to know this as there is every possibility that they either misdiagnose the problem or simply don’t check.

Head Gasket

A much more common problem with older cars, a blown head gasket could lead to other serious problems with a vehicle, making it essential it is diagnosed and fixed as soon as possible.

Another problem the customer can diagnose themselves, thanks to the white gunk (or “mayonnaise” as it is also known as) that spills out of the oil cap, it is nevertheless an essential term for all mechanics to familiarise themselves with.

But what exactly is the “head gasket”? It is the seal that is vital in keeping everything airtight and that no fluids (like water and oil) mix in with each other.

This is what results in the “mayonnaise” spilling from the oil camp. In other words, the breakdown of the head gasket violates any health and safety regulations in terms of roadworthiness.

It is, nevertheless, a simple fix. However, depending on the extent of the damage as well as the size of the engine, the fix could get more expensive.

You should make the customer aware of this when you bring their attention to the problem. They will thank you for it later.


When a car “misfires” this refers to the combustion process that ignites the engine. It means one of the engine cylinders is not firing up properly or not firing up at all.

This can be the result of a few factors, ranging from the electrical flow from the spark plug is faulty to no electricity being sent whatsoever.

It, like others on this list, is a simple problem to diagnose. The engine, when turned on, makes a rattling sound and the reduction in power will be very noticeable.

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