Punto 1.4 petrol engine - loud hissing noise

Filled up the coolant and observed it for couple of days. Drove around 75 kms in that time. Situation is not great - coolant loss continues but at a lower rate. One of the hoses with a spring clamp has wet area around it. That is one of the places where it is leaking. Unfortunately no screws to tighten it, just a spring clamp. Either I have to get a new hose + clamp or at least a clamp with a screw. With 99.rpm stopping Punto and Linea spare parts, I don't have any way of getting the spare parts in my place. I may be able to get a generic clamp of that size from a local automobile shop and try fixing it. For that I have to drain out the coolant first and then try the fix. At the end if the new clamp does not fit or fails to stop leakage or if the hose itself has a problem I will have to drive to Manickbag FASC at Hubli. Around 12 ltrs of petrol + 1 day wasted in the effort. What a pain it has become now

But the real problem is - I am not confident that FASC will be able to give me a definite solution. Manickbak service station at Hubli has some Tata legacy; they believe in trial and error instead of trying definite methods like pressure testing. Though it is possible to pressure test the coolant system I doubt Manickbag at Hubli has equipment and expertise to do that. Please give me suggestions about how to verify coolant system leakage - how can I verify leakages have been fixed for sure. Now I am really a frustrated vehicle owner (won't blame Fiat though - it can happen with any car for that matter).

Today morning when I checked I was surprised to see no traces of new leakages. I will be really worried if I don't see any leakages but the coolant level keeps doing down - head gasket blow up? or may be air lock perhaps? This car engine has never been revved beyond 3500 rpm. Always serviced well in time. Engine temp gauge has never crossed middle mark. What is going on?!

Might have to do with some radiator leak. Sometimes not so easily visible to eye. Had this issue with the Siena got it fixed by a local radiator specialist.

I agree with you @asimpleson - it is hard to find minor leakages in the radiator fins because it is not a straight surface to look at. I will have to first find a local mechanic who can investigate it. Sad part is - this GP seems to have aged all of a sudden as soon as its 5th birthday approached! It will be tough to live with it if it keeps throwing new surprises frequently like this. Problems I faced in last 1 year:

1. Battery failure. OEM Exide failed in 4 years. Replaced with Amaron through Battery Bhai.
2. AC relay failure draining out the battery completely. Fixed DIY.
3. Driver side central lock failure. Fixed DIY.
4. Rear shocks had leakage. Replaced them at FASC.
5. The hiss sound explained in the beginning of this thread. Had to tow it 100 kms. Fixed as FASC.
6. Suspected coolant leakage. Partly fixed at FASC. Still under investigation.

Apart from this I had to do other periodic replacements like belts etc. which are part of maintenance schedule. So I will not take them as a problem.

Now I am scared to take it out at odd hours or on long trips. I feel its reliability has come down drastically. I am always little scared about this stopping on the road (can't even imagine towing it because of previous bad towing experience). Can I do some proactive service to improve the reliability of the car? I will do whatever is needed to keep it for another 5 years if possible. Please suggest.

Check the wheel bearings, lower arms and tie rods (or if possible all suspension components), the entire coolant lines once again, keep an eye on engine temp. gauge a bit more cautiously for some more time. How is the car body, try getting some anti-rust treatment again. Power steering oil needs complete change at fixed intervals do see if that is done. Is the transmission oil changed at any interval, you might consider that (I generally go for fluid changes a bit before schedule).

@asimpleson thank you very much for the inputs.

Wheel bearings, suspension etc. have been inspected in last service done in Dec-2014. Some suspension components have been changed. Everything else looks good.

Car body is in very good condition. I have not noticed any rust anywhere except one wheel arch panel which has a minor dent. Probably I don't need antirust treatment again at this time because the previous under body antirust has not come off anywhere.

All fluids have been changed strictly as per maintenance schedule. In my case every 2 years because time limit comes before I run the car beyond mileage limit for the maintenance.

So far the car has run average of 8000 kms a year. In future it will come down because I have moved to my home town and work from home all the time. No daily office commute. No commute to drop the kid to school since he is on home schooling so far. Only commute is for some errands in the town + occasional commute to my parents' place 60 kms away. Hope I can enjoy this beautiful machine for some more years!

Yes, it should serve you well for years as far as you manage to keep the engine healthy. Might I suggest you to install and use a battery terminal switch or car battery switch looking at your usage profile and location. Better for keeping the electricals from malfunctioning and also to keep battery in best health in periods of inactivity. You need to install it on -ve side terminal (strictly).

@asimpleson As you suggested did a trip to FASC today. Got the coolant lines checked. One hose going from engine block to the heater had cracked. Replaced the hose @ 700 Rs. Plastic socket at the engine end of the flexible rubber hose going from engine to coolant tank was leaking. They just cut the plastic socket and clamped the pipe to the engine block. Coolant hose had a leakage in another place too - changed the clamp from spring clamp to hose clamp with screw. They sealed all the joints they had opened with what is called as "slag" in their terminology. Actually the "slag" is a compound named shellac used for sealing engine head gasket. When I was a boy I had seen my uncle using it for sealing the head gasket of 1/2 HP water pump engines. It is the same thing they used for sealing the coolant line joints. I think Fiat customers are getting the benefit of TATA service station in the same campus

Now after reaching home I see some black stuff on the inner top surface of the coolant tank. Wondering whether the mechanics emptied the coolant in a dirty bucket and poured it back May be I will have to drain the coolant once and pass it through a filter to remove the gunk? or even replace the coolant? or stop worrying about it if that is a common thing in the coolant tank. Please suggest.

I think filtering should do the trick. Filter it twice outside and then fill in coolant again. Repeat again after few day of running.

They must order this one and replace again I guess. Will that quick fix you mentioned work. No clear idea, just be cautious. Coolant is so critical, even more on diesels.

I think that quick fix is functional, though not as intended by Fiat. It looks like Fiat's design was made so that the plastic socket snaps and dumps the coolant if the pressure inside the coolant circuit exceeds some preset limit. Probably the coolant tank cap also has similar protection mechanism - it looks like the rubber washer in the cap is made to sacrifice itself and dump the coolant if the pressure increases beyond some limit.

The more I go to Manickbag FASC in Hubli, the more repulsive it gets. Those guys are road side mechanics in Fiat uniform - that's it. Given an option I will not go to Manickbag in Hubli. If I leave Hubli next nearest is Belgaum - which is double the distance. However, there also mechanics will of same nature because it is all same belt (North Karnataka belt known for hardy people - I am being nice in this description; you will know what I mean if you have dealt with those people). I am waiting for 99.rpm to start Punto and Linea parts sale. With 99.rpm shutting down Fiat spare parts I am worried to touch anything. What will I do if it breaks? That fear is holding me back from trying it on my own. I will order such things and change it myself. Is there any other option for Fiat parts? Please send me contacts if you know any.