Coolant Leak

When looking at another issue, I noticed that the coolant in the car was looking very low and needed topping up, normally the car does not use any extra coolant, so I gave the engine bay a good inspection to see if anything looked amiss.

I have found that around where one of the main coolant hoses goes into the engine on the top right there is a very crusty build up of what looks like coolant.

Looking at the manual I cannot seem to find the part that the pipe joins onto or is it part of the engine.

If you look at the pictures below, it does look like the metal part is leaking where the hose connection onto, but I would be surprised if it was that part , is that part replaceable?

I have the 1L manual.

Looking at the photo, I would think that the metal spigot is either pressed or screwed into the engine block. It likely has an o-ring on it, sealing the coolant circuit. 

Do you have access to a microfiche? May be worth a look to see if Toyota quote a part number for a sealing ring here? 

These aren't the best drawings I have seen, but better than nothing maybe? Maybe not... 😅

Radiator & water outlet for Toyota iQ GJ10, 1 generation 11.2008 - 03.2016 - Toyota Car and Auto Spare Parts - Genuine Online Car Parts Catalogue - Amayama

I'm guessing if it's pressed, there would not be able to repair it, is there a possibility that it's coming out of the hose and just collecting in this area do you think. 

Possibly? 

How mechanically minded are you? 

If it were me, I'd drain the coolant, remove that hose, and have a look for any witness marks of antifreeze making its way out of the seal between the hose and the spigot. 

Clean up the crusty rubbish on the spigot, clean up the inner bore of the hose, use some silicone grease to refit the hose and use a jubilee screw clasp to tighten the hose in place as opposed to those stupid spring clips manufacturers insist on using. 

If it continues, and the witness is the same as it is now, then you know you have an issue with the spigot itself. 

Might also be worth looking inside when the hose has been removed to see if you can identify whether the spigot is pressed, screwed, or if it is cast onto the cyl. head and has indeed cracked. 

If you don't fancy this, just check the coolant once a week and drive the car until it becomes an MOT failure (minor leaks are often just advisories).