60k on the clock with not a single problem but just notice a leak bottom at the bottom of the radiator on nearside sludgy black stuff

Any ideas on cause, intercooler, turbo seals or hose seals, whatever it looks expensive

Hose seals. Replace the seals or tighten them up and you'll be fine.
That section of the intake is always with a positive, higher than atmosferic, pressure.
And you'll always have some oil in the intercooler because of the crankcase ventilation system.

Alex,

thanks and should I tighten up first see if it still leaks & then replace seals.

Is it difficult to do replace the seals, looks like underneath the car is the only access.

Clean the area after tighthening up in order to see more efficiently if leaks again...
For ease, use a brake cleaner.

is it possable that the intercooler wants removing and flushig out to clean it i remember that on my old disco this was recmended at approx 60.000 miles  rainy-city
xs

Is that recommended on Freel2 at 60k?

hi dont know but i do know,i am sure somebody on here will know if you ask you always get a certain amount of oil resadue in any intercooler on a diesel (this does not mean that the turbo seals are on the way out ) its normal as long that its not excessive amount if you do decide to clean it remove the intercooler a little petrol wash it out but let the petrol vapours evaporate b4 you re fit and start the engine hope this helps you  rainy-city
xs

Well just had my steering rack, pump etc replaced and ask the dealer to take a look at this leak while they had the undertray off.
Anothe problem they reckon the intercooler welds are cracked and leaking oil? sounds dodgy to me I know that there is a lot of pressure going through that system but on a 5 year old car?

Cracked intercooler - you have been trying hard, or has the car had a front end impact?

Hot compressed air with a tiny amount of oil vapour (from turbo), enters a chiller - the intercooler. It is natural the the vapours should condense out, so the intercooler will get contaminated with oil. The intercooler is under pressure from the turbo, so when oil accumulates, if there is a means of escape it will find it.

The good news is if the air flow is blocked, the intercooler doesn't work and you have no oil residue - I speak from bitter experience, so yours is working.
Our old Skoda and the sons Audi both benefitted from cleaning with a strong solvent at around 70K.
No one is going to give a definate answer as to when it should be done as, it does depend on several factors, such as:
Turbo condition, Oil type, operating temperature, driving style, long/short journeys.

The good news is, it's a good sized intercooler, so a small amount of oil (which can produce a large stain!), isn't going to drastically effect it's operation. But it would be wise if you do take it off, to spend an hour with some "solvent" cleaning it.

I'm sure I wouldn't reccomend petrol as the solvent due to it's flamability, but .... Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner