Cooling System Resurrection
A complete overhaul of the 166's cooling infrastructure
By Admin
Why Cooling Matters Most
If you buy a Busso V6, the cooling system should be your first priority. These engines are robust, but they do not tolerate overheating. A single overheat event can warp the aluminum heads, and at that point, you're looking at a major rebuild.
The Full Parts List
Here's everything I replaced:
- Nissens aluminum radiator (aftermarket, direct fit)
- Wahler thermostat (82°C opening temperature)
- Graf water pump with metal impeller
- Complete silicone hose kit (11 hoses total)
- Expansion tank with new cap
- All spring clamps replaced with proper worm-drive clamps
- Coolant temperature sensors (both)
The Process
Working on the cooling system of a 166 is a lesson in Alfa Romeo packaging. The engine bay is tight, but everything is accessible with patience. The most challenging part is the lower radiator hose, which runs behind the engine mount. Budget extra time for this.
I opted for silicone hoses throughout. Yes, they cost three times more than rubber. But they will last essentially forever, handle heat better, and look proper in an engine bay that deserves respect.
Results
After the overhaul, the cooling system maintains 85°C rock-steady in any condition. Summer heat, city traffic, Autobahn cruising — the temperature needle sits exactly where it should. The peace of mind alone is worth every euro.