WE RECOMMEND YOU CHANGE YOUR WATER BOTTLE / RADIATOR EXPANSION TANK EVERY 80000km – 100000km ( preventative maintenance).
These bottles are made out of plastic and therefore have a heat cycle. Cracks occur as a result of excessive thermal expansion & contraction.
It will either crack or in extreme cases it will explode with rapid water loss and could result in your car overheating. You will have to have the vehicle towed.
Cars prone to this bottle failure:
• All petrol Be-Em’s – all e46 (3 series 1999 – 2004) , x3, x5, e39, e60 (5 series) & e65 ( 7series) .
• Diesel cars – occurs at a much higher mileage and is not as frequent; these engines tend to be a lot cooler and eminent less heat.
In some cases the coolant light will come on and you will be filling up once or twice a week but with no overheating. This is a slow leak as a result of a hairline crack. Some clients drive like this but it is not advisable. Do get to a mechanic as soon as possible.
You need to know when you have replaced it and keep a record of it. This part has no exact expiration date and there is no warning when the bottle cracks.
When it will happen is unknown, so prevention is better than cure.
The bottle is located on the right hand side of the engine (if you facing it) – next to the radiator.
See diagram for different expansion tanks below.
Note: There is a Vast amount to COOLING SYSTEM; radiator, water pump, flanges, connectors and hoses also age & leak. Hoses in particularly become very brittle.
E90
E60 and E65
Z3 and X5
E46 and X3 most common
