Overheating

[biker1981]

Bought a new t25 with Passat Diesel engine was told it over heats after 9 miles. I asked how he knew and he said the expansion tanks starts leaking,

I was thinking of buying new radiator as its not really getting hot, and replacing water pump.... I know they can be hard to bleed,.... Any advice on what else I should look at please ? Also... Sorry if silly question but should I buy a t25 radiator or a Passat one and make it fit ?

[kevtherev]

No you just need a T25 Diesel radiator (thicker)
how do you know you need one?
If the radiator isn't getting hot then the thermostat is not working
if the expansion tank leaks from the cap you need a new cap
if the expansion tank leaks from a split you need a new expansion tank

not hard to bleed, just follow the guide in the wiki.

[Oldiebut goodie]

Read all the posts on AAZ/1.9 overheating - it will give you an idea as to which could be causing the overheating. Could be radiator, could be water pump rotation setup is wrong. Loads of like posts on the Brickyard. Rarely is the thermostat as people put new ones in as the easiest option to start with and has no effect.