CKFCar Known Faults

Cooling Faults

89 known faults tagged with Cooling

DPF Blockage

2007-201430,000–70,000 miles£150–£800

The small 1.4 TDI Fabia is often used for city commuting — the exact use case that blocks DPFs. The engine's small displacement means low exhaust temperatures even at motorway speeds.

EGR Valve and Cooler Failure

2014-201970,000–140,000 miles£600–£1100

The Ingenium 2.0 TD4 engine in the Discovery Sport develops EGR valve and cooler failures. The cooler can cause coolant to enter the intake on higher-mileage examples.

EGR Cooler Failure

2008-201770,000–140,000 miles£600–£1000

EGR cooler failure on the Insignia 2.0 CDTi causes coolant to enter the intake manifold — a serious failure that requires immediate attention.

EGR Cooler Failure and Coolant Loss

2008-201570,000–140,000 miles£500–£900

EGR cooler failure is common on the B8 A4 TDI. Internal corrosion allows coolant to leak into the intake — initially causing rough running and white smoke.

EGR and Timing Belt Failure

2008-201780,000–140,000 miles£500–£1500

The Q5 TDI shares the EGR cooler failure of the wider VAG TDI family, plus the timing belt must be replaced at 140,000 miles — a job many owners defer dangerously.

EGR Failure and Coolant Loss

2007-201070,000–140,000 miles£700–£1200

EGR cooler failure on the E60 520d N47 causes internal coolant leaks into the intake manifold. Combined with EGR valve carbonising, both components typically need replacing together.

EGR Valve and Cooler Failure

2007-201660,000–130,000 miles£500–£850

EGR failure on the Tiguan Mk1 2.0 TDI causes power loss and in more serious cases, coolant loss from the EGR cooler. Both components often need addressing together.

EGR Cooler Failure

2010-201470,000–140,000 miles£500–£900

EGR cooler failure on the Passat B7 2.0 TDI causes coolant loss and white smoke. The internal corrosion of the cooler allows coolant into the intake manifold.

EGR Cooler Failure and Coolant Loss

2012-201960,000–130,000 miles£500–£800

EGR cooler failure on the Kuga Mk2 causes coolant to enter the intake. Left unchecked this results in rough running, white smoke and potential engine damage.

EGR Valve and Cooler Failure

2013-202140,000–90,000 miles£300–£700

EGR failure on the Transit Custom 2.0 TDCi is extremely common in fleet use. The valve carbons up rapidly in stop-start environments.

Cooling System Thermostat Housing Failure

2007-201070,000–140,000 miles£200–£400

The plastic thermostat housing on the N47 is notorious for cracking and causing coolant loss. BMW used plastic for this component in a bid to save weight — it fails prematurely.

Engine Thermostat Sticking Open

2012-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201460,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2004-201060,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2005-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2010-201960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2004-200960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2013-201760,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2004-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2008-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2008-201760,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2009-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201460,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2011-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2003-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201760,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2009-201360,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201860,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2005-201460,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2011-201860,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2011-201860,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2010-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201460,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2009-201660,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2015-202160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2004-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201860,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201760,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2013-202160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2007-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-202060,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2011-201860,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2008-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201660,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2006-201260,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2005-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2004-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2008-201760,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2012-201960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2010-201560,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Engine Thermostat Sticking Open

2014-201960,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Water Pump and Coolant Pipe Leak

2009-201860,000–120,000 miles£300–£500

The OM651 engine uses a vacuum-actuated water pump that frequently leaks. The plastic coolant junction pipe above it also cracks with heat cycling.

Water Ingress into Spark Plug Wells

2002-200850,000–100,000 miles£100–£200

The core plugs (freeze plugs) between the spark plugs rust, leaking coolant into the spark plug wells.

Thermostat Housing Leak

2012-201940,000–80,000 miles£150–£200

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

Water Pump / Coolant SIlca Bag Rupture

2013-201940,000–90,000 miles£800–£1500

The coolant expansion tank contains a 'Silica bag' designed to extend coolant life. This bag frequently bursts, sending silica gel through the engine and destroying the water pump and heater matrix.

EGR Cooler Recall / Fire Risk

2012-201830,000–150,000 miles0

A huge global recall affects the F30 320d due to the EGR cooler leaking glycol coolant into the intake manifold, which mixes with soot and can catch fire.

Water Pump Leak and Bearing Failure

2005-201160,000–100,000 miles£150–£250

While incredibly reliable, the 1.3 VVT-i engine's most common weak point is the water pump, which develops a leak and noisy bearing.

Water Pump Leak

2014-201950,000–100,000 miles£180–£300

Coolant loss on the Corsa E 1.4 is frequently traced back to a leaking water pump seal. If ignored, the engine will overheat rapidly.

DPF Blockage and Eolys Fluid Depletion

2006-201260,000–100,000 miles£200–£500

Peugeot uses a wet DPF system requiring an additive (Eolys/Cerine fluid) to lower the burning temperature of soot. The fluid runs out, or the DPF blocks from short trips.

Porous Cylinder Head (BKD Engine)

2003-200850,000–120,000 miles£1200–£2000

Early 2.0 TDI 140bhp engines (engine code BKD) suffered from porous cylinder heads, causing coolant to leak directly into the combustion chambers or oil ways.

Thermostat Housing Leak and Failure

2006-201340,000–90,000 miles£200–£350

The plastic thermostat housing on the R56 warps and cracks, causing coolant leaks. The integrated temperature sensor also fails, causing erratic fan behaviour.

Water Pump and Timing Belt Failure

2004-200960,000–120,000 miles£350–£1500

The water pump on the 2.0 TDI is driven by the timing belt. If the pump fails or seizes, it destroys the timing belt, leading to catastrophic engine damage.

Diesel Particulate Filter (DPF) Blockage

2007-201280,000–150,000 miles£250–£1500

A blocked DPF on the N47 is highly common, often a secondary symptom of thermostat failure, glow plug module failure, or exclusively urban driving.

EGR Thermostat Failure preventing DPF Regeneration

2007-201260,000–120,000 miles£250–£400

The E90 320d has two thermostats (main and EGR). When either fails open, the engine never reaches the 88°C required for DPF regeneration, leading to inevitable DPF blockage.

Glow Plug Failure and White Smoke on Cold Start

2011-201880,000–150,000 miles£100–£250

Glow plug failure on the Focus Mk3 TDCi is a common higher-mileage issue. Failed plugs cause white smoke and rough running when cold, clearing quickly once the engine reaches temperature.

EGR Cooler Failure and Intake Contamination

2012-201570,000–130,000 miles£500–£800

EGR cooler failure on the Astra J 1.6 CDTi causes coolant loss and in severe cases, coolant enters the intake manifold. This is a more serious failure than a simple EGR valve block.

EGR Valve and Cooler Failure

2011-201860,000–120,000 miles£400–£700

The EGR valve and cooler on the Mk3 Focus 1.6 TDCi are known to fail together. EGR cooler failure can cause coolant to enter the intake — a more serious failure than a simple blocked valve.

Water Pump Failure (Belt-Driven Internal)

2011-201880,000–140,000 miles£250–£500

The 1.0 EcoBoost uses a belt-driven water pump. When the pump fails, coolant circulation stops and the engine overheats rapidly. Because it is inside the engine, early detection requires vigilance.

Coolant Loss from Integrated Exhaust Manifold

2011-201860,000–120,000 miles£500–£900

The 1.0 EcoBoost's unique integrated exhaust manifold/cylinder head design causes head gasket stress. Coolant loss without visible leaks is a known issue on higher-mileage Focus Mk3 examples.

Coolant Loss and Head Gasket Failure

2014-201960,000–120,000 miles£500–£800

The Corsa E 1.4 turbo shares the head gasket vulnerability of its predecessors. Coolant loss without visible external leaks is a red flag that demands immediate investigation.

Thermostat Failure and Overheating Risk

2012-201850,000–100,000 miles£80–£180

The plastic thermostat housing on the 1.0 EcoBoost is prone to cracking. A stuck-open thermostat causes the engine to run cold and burn more fuel; a stuck-closed thermostat causes rapid overheating.

Coolant Loss and Head Gasket Failure

2006-201460,000–120,000 miles£400–£700

The Z12XE and Z12XEP 1.2-litre petrol engine in the Corsa D is known for coolant loss. In many cases this escalates to head gasket failure if not caught early.

Timing Belt Failure and Water Pump Failure

2011-201580,000–130,000 miles£800–£1500

The 2.2 SD4 Freelander 2 has a timing belt with a 120,000-mile interval but the water pump is driven by the same belt — and water pump failure destroys the belt. This is a common and expensive failure.

EGR Cooler and Valve Failure

2007-201270,000–130,000 miles£600–£1200

EGR cooler failure on the N47 is common from 70,000 miles. Coolant leaks into the intake manifold and the EGR valve sticks, causing power loss and rough running.

EGR Cooler Failure and Soot Ingestion

2009-201360,000–120,000 miles£400–£800

The 1.6 TDI common-rail engine has a well-documented EGR cooler failure. Coolant can leak into the intake causing rough running or, in severe cases, catastrophic engine failure from hydro-lock.

Coolant Loss from Cylinder Head

2012-201860,000–120,000 miles£500–£900

The 1.0 EcoBoost has an integrated exhaust manifold cast into the cylinder head. This design causes head gasket stress and coolant loss, sometimes causing overheating.