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MOTRS

MGF / MG TF

1995-2011 / Roadster / United Kingdom

All MGF / MG TF problems All workshop problems
Critical Cooling System Issues

Expansion Tank Cracking

Symptoms

Coolant weeps or sprays from a crack in the plastic expansion tank. The tank may split suddenly under pressure, dumping all the coolant. Coolant level drops with no apparent engine fault.

Cause

The expansion tank is made from plastic that becomes brittle with age and heat cycling. After 15--25 years, these tanks are living on borrowed time. The pressurised cooling system subjects the tank to constant stress.

Fix

  1. 1 Replace the expansion tank ($40--80 AUD). Inspect it at every service -
  2. 2 look for discolouration, stress marks, and hairline cracks, particularly around the cap seat and hose connections. Some owners carry a spare tank in the boot as insurance
Cost mentioned in fix
$40

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// More MGF / MG TF problems

Other known issues

Minor Cooling System Issues

Thermostat Failure

The engine overheats, particularly at sustained speeds. Alternatively, the engine never reaches operating temperature (thermostat stuck open), which causes poor fuel economy and increased wear.
Critical Cooling System Issues

Water Pump Failure

Coolant leak from the pump weep hole. Bearing noise (grinding or whining) from the pump area. Overheating from reduced coolant flow if the impeller corrodes or the bearing seizes.
Critical Cooling System Issues

Coolant Hose Deterioration

Coolant leaks from split or perished hoses. Hoses feel soft, swollen, or show surface cracking.
Minor Cooling System Issues

Air Locks After Coolant Work

After any work that opens the cooling system, the engine overheats despite the system being full of coolant. The heater blows cold air. Temperature gauge spikes erratically.
Minor Head Gasket Failure (K-Series Engine)

What Happens
Minor Head Gasket Failure (K-Series Engine)

Why It Happens
All MGF / MG TF problems