Engine Cooling System Failure

[Gravy]

I am the second owner of a 2000 build 4.4L V8 X5, vehicle has travelled approx 126000 Km.

I am becoming very sceptical regarding BMWs ability to produce a vehicle that has longevity after the latest component failure.

It took me some time to analyse why the vehicle was requiring engine coolant top ups. Investigation found that the radiator overflow tank had failed. Longitudinal cracks were evident in the casing below the flange where the top of the tank is attached to the bottom section also hairline cracks were found in the top in close proximity to where the radiator cap is installed.

An attempt to repair the cracks using "Araldite" did not provide a positive outcome.

Replacement of the tank and a new cap have resolved the problem. The cap was replacd as a preventive measure in case high pressure had caused the tank failure.

Two issues evolved from this exercise;

1. The original level sensing switch could not be installed without increasing the clearances on the bayonet fitting,

2. The new radiator cap could not be tightened sufficiently to achieve a seal until the root diameter of the male thread on the tank was reduced.

Confidence level in BMWs replacement parts QA is now compromised and I wonder what other gremlins will become apparent during the life of the vehicle.

I raise this issue because I have owned numerous Japanese and Australian built vehicles, at 30% of the capital outlay, in the past and have not seen the gravity of failed components in vehicles of similar age.