MG 3 Common Problems & Reliability

Based on 897 MOT tests from 158 vehicles analysed by VehicleScore®. The figures below describe that VehicleScore® sample. Recurring issues seen in VehicleScore® MOT data are not a claim that every MG 3 has the same fault.

MG 3's have a very good reliability rating of 708/999. The score was calculated from the average of every MG 3 that has had a registered MOT.

We calculated all of the below figures by getting the score from each vehicle make/model/year/fuel, which are each calculated a score. We then generate the average score, taking into account factors such as mileage and emissions.

Also check BHP & performance, road tax, fuel economy, and CO2 emissions for the MG 3.

MG 3 (example)

Check the reliability of your MG 3

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Fuel Type	Year	Reliability Score	Avg Mileage	Sample Size
Petrol	2019	826/999Excellent	68,997 miles	1,673 vehicles
Petrol	2016	681/999Good	66,157 miles	2,080 vehicles
Petrol	2015	618/999Good	72,084 miles	1,064 vehicles

How reliable is the MG 3?

Based on 897 MOT tests from 158 vehicles analysed by VehicleScore®.

Vehicles

158

MOT tests

897

Pass rate

79%

Median mileage

45,202 mi

Recurring issues seen in VehicleScore® MOT data are inspection findings from this sample. They are not a statement that every MG 3 has the same fault. The median VehicleScore® in this sample is 831 out of 999.

Common MG 3 MOT problems

These groups combine equivalent MOT comments, such as the same tyre note on different corners. Counts are comment occurrences in the sample, not a percentage of cars.

Tyre wear

VehicleScore® MOT data includes 154 advisory comments and 19 failure comments in this group. Seen as both an advisory and a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record tyres that were worn, damaged, or close to the legal tread depth when the car was inspected.

What to inspect

Check the tread depth and look for uneven wear, cracking, or damage on all four tyres.

Example MOT wording: NEARSIDE FRONT TYRE WORN CLOSE TO LEGAL LIMIT/WORN ON EDGE (5.2.3 (E))

Brake disc wear

VehicleScore® MOT data includes 65 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record brake discs that were worn, scored, pitted, or corroded.

What to inspect

Look at the disc faces for deep scoring, a lip at the edge, and corrosion.

Example MOT wording: FRONT BRAKE DISC WORN, PITTED OR SCORED, BUT NOT SERIOUSLY WEAKENED (1.1.14 (A) (II))

Corrosion

VehicleScore® MOT data includes 55 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record corrosion the tester could see on the body or structure. Corrosion already named on a spring, brake, or other component is counted with that component.

What to inspect

Inspect the underside, sills, and subframe for heavy corrosion, especially where an advisory mentions it.

Example MOT wording: FRONT SUB-FRAME CORRODED BUT NOT SERIOUSLY WEAKENED (5.3.3 (B) (I))

Brake pad wear

VehicleScore® MOT data includes 41 advisory comments and 6 failure comments in this group. Seen as both an advisory and a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record brake pads that were worn or below the inspection limit.

What to inspect

Ask for recent pad replacement and look at the remaining pad thickness.

Example MOT wording: FRONT BRAKE PAD(S) WEARING THIN (1.1.13 (A) (II))

Suspension arm issues

VehicleScore® MOT data includes 31 advisory comments and 10 failure comments in this group. Seen as both an advisory and a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record a worn, corroded, or damaged suspension arm or its pin.

What to inspect

Look for play or corrosion at the arm and ask whether it has been replaced.

Example MOT wording: OFFSIDE FRONT SUSPENSION ARM PIN OR BUSH WORN BUT NOT RESULTING IN EXCESSIVE MOVEMENT (5.3.4 (A) (I))

Oil leak

VehicleScore® MOT data includes 33 advisory comments in this group. Seen mainly as an advisory. These are comment occurrences, not a share of all cars.

These MOT comments record an oil leak noted by the tester. Shock absorber misting is counted as a damper issue, not as an engine oil leak.

What to inspect

Look under the engine for fresh oil, and check the oil level.

Example MOT wording: OIL LEAK, BUT NOT EXCESSIVE (8.4.1 (A) (I))

Windscreen damage

VehicleScore® MOT data includes 24 failure comments in this group. Seen mainly as a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record chips, cracks, or other windscreen damage in the driver’s view.

What to inspect

Look for chips and cracks, especially in the area swept by the wipers.

Example MOT wording: FRONT WINDSCREEN WASHER PROVIDES INSUFFICIENT WASHER LIQUID (3.5 (A))

Lamp and bulb faults

VehicleScore® MOT data includes 20 failure comments in this group. Seen mainly as a failure reason. These are comment occurrences, not a share of all cars.

These MOT comments record a lamp or bulb other than a headlamp or indicator.

What to inspect

Switch on the side, brake, fog, and number-plate lamps.

Example MOT wording: SUPPLEMENTARY RESTRAINT SYSTEM WARNING LAMP INDICATES A FAULT (7.1.6 (A))

MG 3 MOT reliability by year

A model year is only commented on when VehicleScore® has at least 5 vehicles from that year.

Year	Vehicles	MOT tests	Pass rate	Recurring issues seen
2026	9	0	—	No recurring grouped MOT issue in this year sample
2025	15	1	100%	No recurring grouped MOT issue in this year sample
2024	12	0	—	No recurring grouped MOT issue in this year sample
2023	8	10	90%	Tyre wear, Brake disc wear
2022	13	24	95.8%	Tyre wear
2020	5	20	85%	Tyre wear
2019	13	77	81.8%	Tyre wear, Brake disc wear
2018	17	120	85%	Tyre wear, Corrosion
2017	17	141	82.3%	Tyre wear, Brake disc wear
2016	15	152	71.1%	Tyre wear, Corrosion
2015	17	196	77.6%	Tyre wear, Brake disc wear
2014	10	125	75.2%	Suspension arm issues, Corrosion

What to check when buying a used MG 3

This is an inspection checklist based on MOT comments in the VehicleScore® sample. It does not mean the car you are looking at has these defects.

Tyre wear. Check the tread depth and look for uneven wear, cracking, or damage on all four tyres.
Brake disc wear. Look at the disc faces for deep scoring, a lip at the edge, and corrosion.
Corrosion. Inspect the underside, sills, and subframe for heavy corrosion, especially where an advisory mentions it.
Brake pad wear. Ask for recent pad replacement and look at the remaining pad thickness.
Suspension arm issues. Look for play or corrosion at the arm and ask whether it has been replaced.
Oil leak. Look under the engine for fresh oil, and check the oil level.
Windscreen damage. Look for chips and cracks, especially in the area swept by the wipers.
Lamp and bulb faults. Switch on the side, brake, fog, and number-plate lamps.

Buying a MG 3?

Common problems tell you what can affect MG 3s generally. VehicleScore® can check the history of the actual car you're considering.

Where does this data come from?

VehicleScore® analyses MOT histories from vehicles in its own dataset. Sample sizes vary by model, and a small sample is labelled as such. MOT data records roadworthiness and inspection defects. It does not capture every mechanical or electronic problem a car can have, and a comment on one test is not proof that the model has an inherent fault.

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