are casting plugs or expansion plugs in the sides of the engine block and/or cylinder head. The flat steel plugs can corrode from the inside out, and eventually permit coolant to leak from the engine. The plugs may be difficult to see because they are behind the exhaust manifold, engine mount or other engine accessories. The heater matrix is located inside the heating and ventilation, or AC, unit under the dash. It is out of sight so you seldom see a leak directly. But if the heater matrix leaks, or a hose to the matrix leaks, coolant will seep from the matrix or air-con and drip on the carpet. INTERNAL COOLANT LEAKS These are the worst kind of coolant leaks. They are impossible to see because they are hidden inside the engine. They also can be very expensive to repair. Internal coolant leaks are most often due to a failed head gasket. The head gasket may leak coolant into a cylinder, or into the crankcase. Coolant that leaks into the crankcase dilutes the oil and can damage the engine bearings. Workshop repair involves removal of the cylinder head to replace the gasket. This is typically a £400 to £1200 repair job. Head gasket failures are often the result of engine overheating. The overheating may have occurred because of a coolant leak elsewhere in the cooling system, a bad thermostat, or a defective electric cooling fan. When the engine overheats, thermal expansion can crush and damage parts of the head gasket. The damaged areas may then start to leak combustion gases and/or coolant.

Core (Freeze) plugs

Heater Matrix (Core).

Failed head gasket.

Coolant Repair Co

+44 (0) 7722 963863

head gasket and cooling system repairs

e : contact@coolantrepair.co.uk