If you own a Defender or Disco with the Tdi 300 motor , are you aware of the strange mod introduced by Land Rover to the radiator ?
This mod really appears to be an example of the tea girl altering specs , while the engineers were out of the office. If this has caught your eye , read on...
The hot coolant enters the radiator at the top left side and exits at the bottom left side.(as viewed by the driver in the car ). I would expect that the coolant would have to follow a path that spreads its flow over the entire radiator . But no , there is an opening inside the radiator, about the size of a R5 coin, that allows coolant to by pass the main radiator core and flow directly out of the bottom and back to the engine. Over time the radiator core will certainly show a build up of calcium deposits , thereby forcing an ever increasing portion of coolant to by pass the core. Small wonder then that 10 year old Tdi ' s often develop cooling problems.
There are cases reported where this by pass hole is closed up , eliminating overheating problems . Also owners with modified radiators report a slower warm up after start up.
I intennd as a precautionary measure to have my Tdi rad recored and to close up this by pass .
Bookmarks