Category: Cooling & Overheating

Coolant does more than stop freezing, and the corrosion inhibitors are the part that matters. Why mixing types and topping up with water cause real damage.

Overheating in traffic but fine at speed points straight at the fan. How to test the circuit properly, including the air conditioning trick that isolates it.

A heater blowing cold is often the first sign of a cooling system problem rather than a heater problem. How to tell which, and what a sweet smell means.

Both cause overheating but the repair cost differs enormously. How to separate a thermostat fault from a failing water pump using hose temperatures, a bench test and live data.

Head gasket failure gets diagnosed far too readily. What genuinely confirms it, which cheaper faults produce identical symptoms, and the tests worth doing before authorising major work.

Coolant is never consumed, so if the level keeps dropping it is going somewhere. A methodical guide to finding hot-side leaks, internal losses and cap faults on a diesel van.

A structured diagnostic approach to overheating on all three Vivaro generations, from reading the pattern of the fault to pressure testing, fan checks and knowing when to stop.