AAZ Preferred BMW2EXPTNKKIT Expansion Tank/Coolant Reservoir; Reservoir, Pressure Cap, Tank Thermostat; KIT – BMW

$72.78

SKU: BMW2EXPTNKKIT Category: BMW Parts

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P/N: BMW2EXPTNKKIT AAZ Preferred
KIT

Description:

Reservoir, Pressure Cap, Tank Thermostat; KIT

Complete replacement expansion tank, pressure cap, and automatic transmissions thermostat at expansion tank kit to stop coolant leaks on BMW E46, E83, and E53 models with L6 engines
(1) 17137787039 – Original equipment Rein Automotive EPT0018 replacement expansion tank/coolant reservoir for BMW E46, E83, and E53 models with L6 engines
(1) 17111437362 – Uro Parts 17111437362 replacement 80° C expansion tank thermostat for automatic transmissions oil cooler
(1) 17111742231 – Genuine BMW replacement 2.0 BAR expansion tank/coolant reservoir cap with seal
Only fits models with automatic transmissions
Fits BMW 323Ci 2000, 323i 1999-2000, 325Ci 2001-2006, 325i 2001-2005, 325xi 2001-2005, 328Ci 2000, 328i 1999-2000, 330Ci 2001-2006, 330i 2001-2005, 330xi 2001-2005, X3 2004-2010, and X5 3.0i 2001-2006

The expansion tank is the reservoir that holds excess coolant until needed by the engine and allows for the expansion and contraction of coolant as it heats up and cools down.

Expansion tanks are often the highest point in the cooling system of your BMW, whether attached to the radiator or set apart in the engine compartment and connected to the cooling system using a hose. This placement allows any air trapped in the cooling system to be pushed into the expansion tank, where it can escape, and allows coolant to be added to the cooling system without allowing air to enter.

Detecting a Faulty Expansion Tank

Expansion tanks fail when they can no longer hold enough air pressure to prevent the cooling system from overflowing or when they can no longer hold coolant. Expansion tanks that are not holding pressure allow the cooling pressure to release, lowering the coolant’s boiling point and allowing the coolant to expand and aerate and the engine to overheat. Expansion tanks that are leaking coolant allow air to enter the cooling system instead of coolant, causing engine overheating. Steam coming from the expansion tank or coolant dripping from the expansion tank are signs that it has failed.

Failed expansion tank caps can mimic an expansion tank that does not hold pressure. Checking the expansion tank cap and replacing it may solve the problem of an expansion tank not maintaining pressure.

Replacing Your BMW Expansion Tank

Replacing an expansion tank is usually simple. With the exception of expansion tanks mounted to the radiator, crimping the hose from the expansion tank to the cooling system will allow you to unbolt, remove, and replace the expansion tank without draining and refilling the cooling system.

BMW Expansion Tanks.

Left = Driver side and Right = Passenger side.

All parts are priced individually unless identified as a set or kit. “Per car” notes identify how many of a given part your car has and
“Left/Right or Front/Rear” notes means the part fits the left or right side of the car. These parts are still sold individually and you’ll
need to select the appropriate quantity if you plan to replace more than one of this item.