Mechanic jargon buster

Nick Francis

19 Nov 2020


Taking your car in for repairs isn’t a pleasant experience, it’s a nerve-wracking wait to find out what’s wrong with it and how much it will cost to fix. But a new survey by the RAC has found 56% of drivers struggle to understand the language and phrases used by mechanics at service centres, which is makes the ordeal even worse.

Phrases like ‘big end’ and ‘your tracking is off’ leave many bamboozled, which is a problem because it’s important to know what is going on with your car – you’re the one paying for it after all. Don’t worry though, our guide explains the key phrases of ‘mechanic speak’ in good old plain English, so you no longer just have to nod and smile and wait for the bill.

“Your head gasket has blown”

First of all, this is not good news. The head gasket is essentially the seal between the engine block and the cylinder heads, and it’s there to stop oils or coolant getting into places they shouldn’t and ruining the engine. If it has ‘blown’ it means it is damaged and things could be leaking, which is problematic and can be expensive to fix because it requires a lot of labour, sometimes up to 10 hours. In 2018 the average cost of repairing a head gasket was £574.

“Your car is misfiring”

Misfiring means the cylinders in the engine aren’t getting the right mix of fuel and oxygen to ‘fire’ properly. Remember, a combustion engine powers the wheels via a series of controlled explosions which happen in the cylinders, in turn driving the crankshaft. You should be able to tell when your car is misfiring because it will jerk and lurch while driving.

“I need to reset the ECU”

A common one, and not the end of the world. The ECU is the car’s Engine Control Unit – the computer which controls the car. It sometimes needs a reset when an error code or warning light has come up on your dashboard which is found to be incorrect on inspection, or when the warning light won’t turn off once the problem has been fixed. It can be annoying as resetting the ECU deletes its memory, so any driving data you have built up will be gone, and the ECU learns your engine as it goes, so it will have to start again. Crucially though, it is an easy job which takes a few minutes.

“There’s too much play in that”

This can be referring to more or less any part of the car, but it’s usually used when talking about the car’s steering or suspension. When a mechanic says ‘play’ they mean movement or give, so if there’s too much play it’s moving more than it should be. When you turn your steering wheel does it turn a bit without moving the wheels, and turn very loosely at first? That loose movement is the ‘play.’

“Your tracking is off”

Tracking is your front wheel alignment, so the angle they point at. Obviously you want your wheels to point dead-forward when the steering wheel is in the central position, and turn with the steering wheel, but it’s common for the tracking to gradually slip, so the wheels end up pointing to the left or right slightly and steering becomes harder. When driving, does your car steer slightly to the left or right when the steering wheel is central? If so your ‘tracking is off’. Not an expensive or difficult fix.

“The fan belt is slipping”

A confusing one, because it has nothing to do with the fan connected to a car’s engine. The fan belt actually drives the alternator, which is the part which generates electricity and keeps your battery powered up, among other things. If it is slipping then it has come loose and isn’t doing its job properly. You will probably be able to tell when your fan belt slipping as you should hear a high pitched squealing sound from under the bonnet, which sounds awful but isn’t too big a cause for concern. The fan belt may need adjusting or replacing, but it’s a relatively simple and inexpensive job.

“The exhaust is blowing”

This happens when there is a hole in the exhaust system somewhere, and it’s not an uncommon problem. The terminology comes from the fact a hole in the exhaust causes a raspy ‘blowing’ sound, which you should be able to hear while driving. This normally isn’t a huge repair job because the exhaust system is broken down into sections, so the workshop should be able to fix the affected section rather than replace the entire system.

“The pads and discs need replacing”

Here the mechanic is talking about your brakes. The brake pads and discs are what enable you to stop the car, so it’s important you keep them in good condition and repair any damage. It’s a common job, often spotted during MoT tests which examine the amount of life the pads and discs have left in them. Brake pads grip the brake discs to cause the friction to stop the wheels turning, so both the pads and discs wear down over time. They’re designed to do this, don’t worry. And replacing them isn’t hugely expensive.

Nick Francis

19 Nov 2020

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