Ford Focus: Coolant leaks - thermostat housing gasket, turbo lines and radiator end tank (XR5 Turbo / ST225)
Coolant leaks - thermostat housing gasket, turbo lines and radiator end tank (XR5 Turbo / ST225) is a common cooling fault on the Ford Focus on the 2006–2011 cars, and we rate it major. Putting it right costs $300 to $1,800 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 37 documented faults on the Ford Focus.
- Vehicle
- Ford Focus
- Years
- 2006–2011
- Fuel
- petrol
- System
- Cooling
What you are looking at
Example of the part — not this vehicleA double-valve engine thermostat, labelled: the wax capsule is what sticks.
What goes wrong
XR5 Turbos leak coolant from several specific points: the thermostat housing gasket on the cylinder-head side (the leak hides in the bottom corner and needs a mirror to see), the turbo coolant feed and return lines, and the radiator top hose joint at the back of the engine. On 2008-2010 cars the driver's-side bottom corner of the radiator also leaks where the alloy core meets the plastic end tank - and a factory sponge below the radiator soaks up the drips, so the driveway stays clean while the level falls. Aged hoses also delaminate internally and swell. Unfixed coolant loss on this engine feeds directly into the cracked-liner problem, so small leaks here are not cosmetic.
What you would notice
- Coolant level drops but no puddles on the ground
- Coolant smell after a drive
- Swollen coolant hoses; crusty pink/white residue at hose joints
How to check it
Where to look. Thermostat housing at the cylinder head, turbo coolant lines, radiator bottom corner on the driver's side and top hose joint at the rear of the engine
Open the bonnet when the engine is cold: check the expansion tank is at the level mark and look for dried coolant residue (white or pink crust) around the thermostat housing area, hose joints and the driver's side bottom corner of the radiator. Use your phone torch and camera to photograph down behind the engine where eyes cannot reach. Squeeze the main hoses - a spongy or visibly fat hose is delaminating. After the test drive, sniff the engine bay: hot coolant has a sweet smell. Ask when the radiator or any coolant part was last replaced. If a workshop inspection is possible: a cooling-system pressure test at each service is the specialist recommendation for this model - ask for one pre-purchase.
What it costs to put right
$300 to $1,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Does it ever need coolant topped up between services?”
- “Has the radiator, thermostat housing or any coolant hose been replaced?”
Now check the Ford Focus you are actually looking at
Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.
Where this comes from
- AustralianCar.Reviews 'Recalls & faults: Ford Focus XR5 Turbo (2005-11)' (coolant leaks)
- JXL Performance 'Ford Focus ST Mk2 (ST225) Buying Guide' (cooling system issues)
Ford Focus buyer questions
Is coolant leaks - thermostat housing gasket, turbo lines and radiator end tank (xr5 turbo / st225) serious on a Ford Focus?
We rate it major and common on the Ford Focus. XR5 Turbos leak coolant from several specific points: the thermostat housing gasket on the cylinder-head side (the leak hides in the bottom corner and needs a mirror to see), the turbo coolant feed and return lines, and the radiator top hose joint at the back of the engine. On 2008-2010 cars the driver's-side bottom corner of the radiator also leaks where the alloy core meets the plastic end tank - and a factory sponge below the radiator soaks up the drips, so the driveway stays clean while the level falls. Aged hoses also delaminate internally and swell. Unfixed coolant loss on this engine feeds directly into the cracked-liner problem, so small leaks here are not cosmetic.
How much does it cost to fix on a Ford Focus?
$300 to $1,800 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.
Which Ford Focus years are affected?
Our research records this fault on the 2006–2011 Ford Focus. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.
How do I check for it before I buy?
Open the bonnet when the engine is cold: check the expansion tank is at the level mark and look for dried coolant residue (white or pink crust) around the thermostat housing area, hose joints and the driver's side bottom corner of the radiator. Use your phone torch and camera to photograph down behind the engine where eyes cannot reach. Squeeze the main hoses - a spongy or visibly fat hose is delaminating. After the test drive, sniff the engine bay: hot coolant has a sweet smell. Ask when the radiator or any coolant part was last replaced. If a workshop inspection is possible: a cooling-system pressure test at each service is the specialist recommendation for this model - ask for one pre-purchase. Look here: Thermostat housing at the cylinder head, turbo coolant lines, radiator bottom corner on the driver's side and top hose joint at the rear of the engine