Know your car jargon, learn to speak mechanic and don’t get ripped off

car jargon

They might both be talking English but does what he’s saying make sense? (Picture: iStock/photo_concepts)

Every industry has its own language; jargon that only the people working in the business understand. The car industry is no different. We’ve all had a mechanic take one look at our car, shake their head, suck air through their teeth and mutter something using words that might as well be in another language.

The result is people don’t trust garages. One study found that nearly half of drivers think technicians hiding behind confusing car jargon have ripped them off. According to property company Pentific, mechanics rank alongside politicians, car sales execs, journalists, estate agents and builders for being untrustworthy. But you need never be baffled again. Here we explain six pieces of commonly-used car jargon.

Big end

Car jargon

The big end at the bottom of each piston is an integral part of the engine (Picture: iStock/Jannoon 028)

This is frequently used in terms of a big end ‘going’. It sounds painful and for an engine, a big end failure is catastrophic. All internal combustion engines have pistons which go up and down. These connect to a crankshaft that converts the pistons’ energy to power the wheels. The big end is the physical mechanism that joins the pistons to the crankshaft.

It has bearings that are semi-circular metal sleeves. These take a lot of punishment and can wear out. If they do, there’ll be a loud knocking noise from the engine, parts will no longer be as synchronised as they should be and eventually the engine will literally grind to a halt.


A technician usually refers to this as clogged. All modern diesel cars have a DPF or Diesel Particulate Filter. It works by catching the smoke which is made up of harmful particulates. Hot exhaust gases turn the contents of the filter into ash to prevent it from clogging. The trouble is, on short journeys the exhaust gases don’t get hot enough to clear the filter which gets blocked. New filters are expensive and removing them completely isn’t an option if cars are to remain road legal.

Excessive play

It sounds like something adults might accuse kids of getting up to in the school holidays. Actually it’s used in relation to any kind of mechanical connection. It means the part is moving more than it should or in a direction that it shouldn’t. This is usually employed in relation to steering and suspension components.

Diagnostic check

Two words you’ll be hearing increasingly with modern cars. The implication is a technician will do something complicated with a computer, then spend hours carefully poring over spread sheets of data. That couldn’t be further from the truth.

The technician simply plugs a computer into a port in one of the car’s front footwells. The software on the laptop then talks to the car’s computer which reveals any faults it’s detected. As they’re computers they talk in code (mechanics might mention fault codes) but technicians can easily decipher these. The diagnostic check will frequently tell the mechanic the symptoms. They should then be able to work out what the problem is.

Bushes and wishbones

When a mechanic starts talking about bushes and wishbones, they haven’t developed a sudden interest in gardening and poultry. The bush is a vital part of your car’s suspension; the wishbone a suspension component that looks a bit like a chicken bone.

The bush is a rubber liner that keeps the suspension joints snug and stops metal grinding against metal. But because they’re rubber they wear out. The older a car is, or the more miles it’s covered, the more likely its suspension bushes are to wear out. But don’t worry, it shouldn’t be too expensive.


Car jargon

Mayonnaise is a white emulsion-like substance inside the oil filler cap (Picture: iStock/Tomas Majchrowicz)

Oil lubricates engines; water cools them. The two shouldn’t mix. However, sometimes worn engine parts mean water or condensation gets into the lubrication system. The water combines with oil forming an emulsion that looks like Hellmann’s finest. This mayonnaise then gathers on the inside edge of the oil filler cap.

It can mean that the engine’s head gasket is failing. But it might be that the engine isn’t warming up sufficiently in cold weather. If the problem persists in all conditions, take the car to a garage you trust and ask them to investigate. A compression test should warn of any serious problems.

9 comments on “Know your car jargon, learn to speak mechanic and don’t get ripped off

  1. Ray Stevens 31/07/2018 1:28 PM

    reminds me of having purchased a used car last year, which in turn was losing coolant at the rate of 400ml every 7/8 ltrs diesel took it in to the main agent to be told the water was leaking at the jubilee clip on a pipe from the thermostat, 300 pounds later still same problem so took car back to garage then i was informed it needed a new thermostat, you guessed correctly expensive again, then still had the same fault to get the problem sorted, so took it to an another garage who did find the fault it was leaking from the pipe that runs from water pump to the engine block unfortunately he was unable to repair it and suggested i take the car back to main dealer advise them of their findings and then suggest to them Get the job done properly, which they did.. plenty of mechanic and sales chat in between job sorted probably cost me in the region of 800.00 pounds in total NOW the car is perfect…

  2. fred bingham 08/10/2018 8:13 PM

    The ‘con’ rod connects the piston to the crank shaft. the big end is the big end of the con rod and connect it to the crank shaft. The piston end of the con rod is the little end.

  3. Mr A M J Howlett 09/10/2018 11:47 AM

    Nice one, probably could add a few more. 50 years in the motor trade. From tuning and racing in57/60/70. The latter year’s a sevice engineer with MG/Rover.At 76 years old, reluctant to pay for servicing and repairs.

  4. john french 09/10/2018 7:35 PM

    That was very interesting I have heard the terms been used

  5. Stephen Edwards 09/10/2018 7:38 PM

    Surely you should have got some of your money back. I have been a mechanic now for over 40 years and worked on a large variety of vehicles. Due to my age I am now having to take my car to a garage, which at times have tried to kid me, but with no success. I do feel for those who rely on garages for repairs with no experience of what they are talking about and getting charged a large amount of money.

  6. N.L.Parry 10/10/2018 3:26 PM

    Your illustration of a big end is incorrect. The arrow in the picture is pointing at the small end bearing area, where the con-rod connects to the piston. The big end, as I’m sure you knew, is where the larger end of the con-rod connects with the crankshaft via a journal/big end bearing.

  7. Elaine 10/10/2018 6:25 PM

    I know there is something wrong with my car but it has recently passed its MOT so it is obviously nothing too serious. As a woman driver I am terrified of taking it to a garage and asking them to find out why it feels like I am driving a car with no tyres. It shouldn’t have to be so difficult to get a decent reliable diagnosis. I had a headlamp replaced by a garage I had used for years only to find out that they hadn’t properly aligned the beam so that almost failed me my MOT that year.

  8. Lin 10/10/2018 9:45 PM

    I am lucky enough to have a very trustworthy garage to look after my car. I cannot fault anything they do and my Colt passes the MOT test every year, first time. The garage in question is Service u Right at Shaftesbury. Thanks guys!

  9. AeternoSolus 12/10/2018 3:58 AM

    Surely if you take a car to a garage to fix a problem and they charge you but don’t fix the problem you shouldn’t have to pay again. If a plumber came into your house to fix a leaky boiler, charged you and went away but the boiler was still leaking, you’d get him back to put it right. But you wouldn’t pay him again to fix a problem you had already paid to be fixed. Why are garages seemingly exempt to this rule? I get that cars are complicated pieces of machinery but that’s why you give them to an expert to sort out.

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