SevereAffected: 2012-201940,000–80,000 miles

Renault Clio Mk4 0.9 TCe 90bhp — Thermostat Housing Leak

The plastic thermostat housing on the 0.9 TCe warps and cracks, leading to a rapid loss of engine coolant and severe overheating risk.

Severity

Severe

DIY Difficulty

Moderate

Est. Cost

£150–£200

OBD Codes

None

Component Diagram

Cooling

Typical layout and location for the Cooling assembly.

Reference Illustration

Symptoms

Coolant level dropping rapidly
Red temperature warning light (the Clio has no temperature gauge!)
Sweet smell of hot coolant from the engine bay
Heater blowing cold air

Root Cause

The plastic housing degrades due to the intense heat cycling of the turbocharged engine. The rubber gasket flattens out and leaks.

How To Fix

Locate the thermostat housing on the right side of the engine (gearbox side).
Replace the entire housing unit (DO NOT just replace the gasket as the plastic is warped).
The part is cheap (£40-60) and relatively easy to access.
Bleed the cooling system carefully. Cost fitted: £150-200

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£60–£80
Independent Garage	£150–£200
Main Dealership	£240–£320

Other Faults on This Variant

Timing Chain Stretch and Rattle

Severe

2012-201950,000–90,000 miles£600–£800

The 0.9 TCe 3-cylinder engine suffers from premature timing chain stretch, causing an aggressive rattle and potentially fatal engine timing slip.

VVT Solenoid Oil Leak

Minor

2012-201950,000–100,000 miles£10–£80

The Variable Valve Timing (VVT) solenoid located on the top of the cylinder head leaks oil, which runs down the front of the engine.

Keycard Failure / Not Detected

Minor

2012-201920,000–100,000 miles£40–£250

Renault's hands-free keycard system frequently fails to recognise the key, refusing to unlock the car or start the engine.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.