Cooling system fault
There Is Brown Sludge in My Coolant Tank
Search that symptom and the internet says head gasket in four seconds. Four faults produce it, at wildly different costs. Do not guess at this one.
Service
Cooling Systems
Radiator, thermostat, water pump, and coolant flush services.
Cooling system neglect is the fastest way to a blown head gasket. We pressure-test, flush, and replace every component to factory specification using the correct coolant chemistry for your engine.
European engines run at high operating temperatures, and the cooling system works under pressure to hold them there. A small leak, a sticking thermostat or a failing water pump often shows first as a coolant level that keeps dropping or a temperature gauge that climbs in traffic.
We pressure-test the system to find leaks that do not drip, check the coolant for oil or combustion gas contamination, and replace components to factory specification with the correct coolant for your engine. Mixing coolant types is a common way these systems fail early.
From$220coolant flush and pressure test - final price quoted before work starts.
Book this serviceWhat is included
- Cooling system pressure and leak test
- Radiator and expansion tank replacement
- Thermostat and housing renewal
- Water pump and drive belt replacement
- Full system flush with correct coolant
- Heater core and hose inspection
Signs you need this
- You keep topping up the coolant but nothing shows on the driveway
- The temperature gauge climbs in traffic and settles on the freeway
- Brown sludge or oil in the coolant tank
- A sweet smell after driving, or steam from the engine bay
- The heater blows cold at idle
From the workshop journal
Further
reading.
Cooling system faultThe Temp Gauge Climbs in Traffic But It Is Fine on the Freeway
A 2016 Mercedes-Benz C300 that ran warm at idle and normal at speed, with no puddle on the driveway. What a cracked thermostat housing looks like early.
Cooling system faultI Keep Topping Up the Coolant But There Is Nothing on the Driveway
Coolant going down every few weeks with nothing under the car. On VW Group 1.8 and 2.0 turbo petrol engines that is often a leaking water pump housing.
Questions
Common
questions.
It can escape as vapour from a hot component, seep onto hot surfaces and evaporate, or leak internally into the engine. A pressure test finds it. Our article on topping up coolant with nothing on the driveway explains each route.
Not necessarily. A failed oil cooler is a common cause and a much smaller repair. Testing tells the faults apart before anything is quoted.
No. European manufacturers specify particular coolant chemistries, and mixing types can cause deposits and corrosion. Use the specified type, or have it topped up here.
Also in the workshop
Other
services.
- Logbook ServicingManufacturer-compliant servicing that protects your warranty and preserves resale value.From $395
- DiagnosticsDealer-level fault finding and full system scanning across all European ECUs.From $145
- Performance UpgradesECU tuning, exhaust systems, intake upgrades and bespoke enhancements.
Not sure this is the right service?
Book a diagnostic. We will scan every module, road-test the car, and send you a written report with costs before anything is repaired.