Technical Coolant leak

[Ferru1104]

Hi all, greetings from Sardinia!
Subject is a Seicento from 1999 (VIN ZFA18700000153879), a suite edition which I bought for the missus as first car so she can learn, experience, and if God save us but it breaks, there is not major loss. Nevertheless I must admit it grew to our hearts, this little, boxy tarmac runner with its lively 1.1 engine. I've done the obligatory oil/filters/sparkplugs/leads/brakes/tires/coolant job after the buy and it ran great ever since.
Lately though it developed a coolant leak. First I feared the head gasket went bust, but no signs of that, instead it was a literal leak under the car. Tracing it back I found the leak coming from under the heating matrix box. Of course everything under the sound proofing was full of leaves, spiders and mud, the drain fully clogged but thats usual with 20+ years cars. The coolant puddle is under the heater box, I can't name a specific point where from. Further complexity is that the car, being a suite edition comes with air conditioning (it does work!) and all the pipes are in the middle of the engine bay, adding complexity and bruised knuckles to any repair jobs.
Now I would like to ask the experienced forum members what they would recommend.
1. is there a known weak spot that is prone to leak and there is a known fix
2. is it a pain in the back to remove the heating compartment
3. should I just disconnect the in/out hoses form the heating box close them short with a piece of pipe (I'm very much inclined to do this) In that case no more heating but that's life.
4. are radiator leak stop liquids any good, should I go for this route

Thank you in advance for your positive input, enjoy your summer!

 

[ZaphodB]

Generally speaking....Heater matrix's do (or can) fail... but might it be a hose .... and capilliary action is bringing the leaked water to a point where it's impossble to work out where it's truly emanating from ......

and usually the heater matrix is fitted to the car as an assembly (including most of the dash), cos it's easier for manufacture .... but sadly not for post manufacture repair

 

[Ferru1104]

Just to follow this up it all went t*ts up, the head gasket was bust and had to source another one, the heater radiator is punctured so I closed the heating off shorting the in-out pipes.

 

[ccavalles]

The next job will be to change the heater radiator. After some time looking for a leak, I saw that it was coming from that part. I’ve already bought it and it’s not expensive. I will change it. ...

 

[Mike1alike]

Just to follow this up it all went t*ts up, the head gasket was bust and had to source another one, the heater radiator is punctured so I closed the heating off shorting the in-out pipes.

That doesn't sound too bad. New head gasket and rebuilding the head sonds good. And yes, as @ccavalles rightly advises, put a new heater radiator in and everything will be good.

PS: T*ts up sounds quite good!

 

[Ferru1104]

That doesn't sound too bad. New head gasket and rebuilding the head sonds good. And yes, as @ccavalles rightly advises, put a new heater radiator in and everything will be good.

PS: T*ts up sounds quite good!

Well it was bad. The head was warped and cracked, beyond repair. The mechanic sourced another one, got it resurfaced, built it in, bill was over 500€.
The heating matrix was rusted to hell, I threw it out, if the missus wants heating she can fix it herself, I've had it with this heap of manure.
Just can't figure why it wasn't leaking already when we bought the car, my best guess is some kind of leak stop liquid was added to conceal the bloody throat of the cooling system+cylinder head.

 

[Mike1alike]

my best guess is some kind of leak stop liquid was added to conceal the bloody throat of the cooling system+cylinder head

That or possibly the heater was clogged. The traces inside are narrow and they do use to get clogged pretty often.