Citroen C4 Radiator: Specs, Fitment & Common Faults
On the C4, a genuinely specific detail before DIY thermostat housing work: real torque figures that prevent over-tightening from causing the exact leak you're trying to fix.
Illustration for editorial purposes
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A Genuinely Specific Detail Worth Knowing Before DIY Thermostat Housing Work
If you're replacing the thermostat housing yourself, it's genuinely worth knowing a specific detail that catches many DIYers out: on several engines in this range, the housing is secured directly onto the cylinder head with a thin bead of RTV sealant rather than a conventional gasket, using a relatively large number of bolts (commonly 8) tightened to a comparatively light torque figure — documented at around 8Nm on some engines — rather than fewer bolts at high clamping force. Over-tightening these bolts, assuming a higher torque figure "seems safer," can actually crack the housing or distort its sealing surface, causing exactly the leak you were trying to fix. Confirming the genuine torque specification and sealing method for your specific engine before starting is worth doing rather than guessing.
It's also worth knowing that a genuine air lock trapped in the system after any coolant work is a common cause of the same overheating symptoms as a faulty thermostat or pump — always follow the correct bleeding procedure for your specific engine after any repair in this area.
Citroen C4 Radiator: The Part That Keeps Everything Else From Cooking
It's an unglamorous part, but on the Citroen C4, the cooling system is behind almost every serious non-wear engine failure that could have been prevented. Spotting trouble here early is about as cheap an insurance policy as exists against a genuinely expensive repair bill.
Citroen C4 Radiator: OEM Part Number
| Manual gearbox, all engines | Standard radiator with no transmission cooling circuit |
|---|---|
| Automatic (EAT6/EAT8), all engines | Genuinely uses a separate automatic transmission oil cooler, connected via pipes into the radiator's coolant circuit — confirmed shared across the wider PSA Group range (Peugeot and Citroen models sharing one common part number), not a tank built into the radiator itself |
Radiator specification varies significantly between petrol/mild-hybrid and fully electric ë-C4 versions — the electric version uses an entirely different cooling architecture for its battery and motor rather than a conventional engine radiator. Confirm your exact powertrain before ordering.
Citroen C4 Radiator: What It Does
On the Citroen C4, heat from the engine coolant is shed to the surrounding air through the radiator, keeping engine temperature in a safe range. On automatic gearboxes, it often doubles up, cooling transmission fluid through a separate internal circuit too — which is why getting the exact part number right matters more here than on a simple heat exchanger.
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Citroen C4 Radiator: Faults, DIY Difficulty & Aftermarket Advice
These are the same regardless of make or model — see our full Radiator Guide for the three common failure modes, confirming fitment against your VIN, and OEM vs aftermarket guidance.
More Citroen Radiator
The same part, covered across other Citroen models.