IsItAGoodCar
Reliability Guide

Common Problems with the
2021–2022 Morgan Plus Four / Plus Six (CX-Generation)

We've identified 5 known issues that can affect the 2021–2022 Morgan Plus Four / Plus Six (CX-Generation). 1 of these are serious faults that could be expensive to repair.

5
Known Issues
1
Serious
3
Moderate
1
Minor

All Known Issues

Brake Master Cylinder Recall

SeriousBrakes

A critical safety recall was issued for the brake master cylinder which could lead to a loss of braking pressure.

Est. Repair Cost: £0 (Recall)
Warning Signs:

Long brake pedal travel, Soft pedal

What to Inspect:
  • Verify the brake recall has been signed off by a Morgan dealer.
Verified by IsItAGoodCar Research Team

Radiator Leaks

ModerateCooling System

Several early CX-generation cars suffered from failing radiator cores, leading to coolant loss.

Est. Repair Cost: £600–£1,000 (Often warranty)
Warning Signs:

Coolant smell, Low coolant warning, Puddle under the front of the car

What to Inspect:
  • Check the bottom of the radiator for staining.
Verified by IsItAGoodCar Research Team

BMW B58 Oil Filter Housing & Coolant Leaks

ModerateEngine

The B48/B58 engines can suffer from cracked oil filter housing gaskets and coolant return line leaks. The filter housing sits under the intake manifold, making access difficult and labour-intensive.

Est. Repair Cost: £500–£1,200
Warning Signs:

Oil drips under the car, Coolant loss, Sweet smell from engine bay

What to Inspect:
  • Check under the intake manifold for oil or coolant residue.
  • Inspect coolant return hoses and jubilee clips.
Verified by IsItAGoodCar Research Team

BMW B58 Oil Filter Housing & Coolant Leaks

ModerateEngine

The B48/B58 engines can suffer from cracked oil filter housing gaskets and coolant return line leaks. The filter housing sits under the intake manifold, making access difficult and labour-intensive.

Est. Repair Cost: £500–£1,200
Warning Signs:

Oil drips under the car, Coolant loss, Sweet smell from engine bay

What to Inspect:
  • Check under the intake manifold for oil or coolant residue.
  • Inspect coolant return hoses and jubilee clips.
Verified by IsItAGoodCar Research Team

Water Ingress & Weatherproofing

MinorBodywork & Rust

Even modern Morgans are not fully watertight. Doors, windscreen seals and hood fitment can allow water into the cabin, particularly at speed in rain. Owners often fit foam strips to door edges.

Est. Repair Cost: £50–£200 (DIY sealing)
Warning Signs:

Wet carpets or seats after rain, Wind noise at motorway speeds, Water dripping from door edges

What to Inspect:
  • Inspect door seals and windscreen perimeter.
  • Check for water stains on interior wood or leather.
  • Test hood fitment in wet conditions.
Verified by IsItAGoodCar Research Team

Buying Tips for 2021–2022 Morgan Plus Four / Plus Six (CX-Generation)

  • ✓Check the BMW-sourced automatic gearbox (if fitted) for smooth shifts, particularly when cold.
  • ✓Inspect the wire wheels (on Plus Four) or alloy wheels (Plus Six) for any signs of curbing or damage.
  • ✓Verify the fit and finish of the traditional ash frame and hand-beaten aluminium panels, ensuring panel gaps are even.
  • ✓Test the modern digital dashboard and infotainment screen (if fitted) to ensure they operate without glitches.
  • ✓Check the condition of the mohair hood; it is vastly improved over classic models but still requires careful folding.
  • ✓Ensure the vehicle has a full service history; while the engine is BMW, the chassis requires Morgan specialist knowledge.