Technical Fiat Stilo Heater Core Replacement?

[Ralf S.]

My thought is that if the pollen filter is blocked/dirty it would be an obstacle for the air coming into the car, in which case the heater would draw in air from the car rather than outside... and so the air would feel warmer (similar to using the Re-circulation button).

I'll fish out my IR thermometer this weekend and see what mine does.


Ralf S.

 

[aschiuta]

My thought is that if the pollen filter is blocked/dirty it would be an obstacle for the air coming into the car, in which case the heater would draw in air from the car rather than outside... and so the air would feel warmer (similar to using the Re-circulation button).

I'll fish out my IR thermometer this weekend and see what mine does.


Ralf S.

Wrong assumption, the pollen filter is after the blower fan so remove it and and notice what is happening.

 

[Mike1alike]

wellu, I think this is your fix, cleaning the heater. This is the best and effective way to do it:

I fixed the car heater (little radiator inside the car) | FIAT Punto (Mk2/2b)

Hello everyone, I will share with you this great fix, for the case your heater is not working but cooling system works fine, engine temperature is steady good and thermostat works fine. So everything works just fine, then winter comes alog and you have no heat inside the car. And also, it's...

www.fiatforum.com

 

[wellu]

wellu, I think this is your fix, cleaning the heater. This is the best and effective way to do it:

I fixed the car heater (little radiator inside the car) | FIAT Punto (Mk2/2b)

Hello everyone, I will share with you this great fix, for the case your heater is not working but cooling system works fine, engine temperature is steady good and thermostat works fine. So everything works just fine, then winter comes alog and you have no heat inside the car. And also, it's...

www.fiatforum.com

Lemon salt would really be that good..? I've already flushed the heater with hot water on both directions. I think that i wil try those "on the market" products to wash heater system. This is probably only possibility to le right now, because it's now -15°C in here where i live and i cant get this car anywhere warm to flush and fill the system with water. I can uae my workplace's garage, but there is not water available at the garage (or is, but it's water from lake nearby and heated).
One finn merc-addict had good results with CRC radiator cleaner, that can be mixed with coolant. I think that i'll try that and let the car run 1-2h and after that flush water system and heater again. Then fill with pure water, flush and finally coolant.

 

[Ralf S.]

Lemon salt? Is that the same as citric acid..?

It might be worth a try... but I'd have thought a specialist radiator flushing/cooling system cleaner would also contain ingredients to remove coolant-related sludge. Whatever works, I guess..

Ralf S.

 

[Mike1alike]

Yes, that is citric acid (100%).
The comercial radiator cleaners are good for nothing, none of them work. I used one before using citric acid and it did nothing. And check the pictures in my post, the first one with that dirty water that came out of the cooling system. That came out after I used citric acid.
Wellu, the water you use should be demineralized water, so you have to buy it. It's not a large quantity. Punto's cooling system capacity is 4.2 litres, your Stilo is about the same. Use one for first clean (with citric acid) and one or two rounds to rinse the system. Then you put the coolant.
So, you can either do that in your workplace garage or you can do it at your home on hot engine. Heat up some water and take it out to test how long it resist before cooling down and starts freezing. But I think is doable, you don't need much time, it's an easy job. So you have the engine heat up, than carefully take out the antifreeze and put hot water+lemon salt instead (using a funnel). Next, start the engine and in 20 mins of it running it's all clean and you will fill the heat inside the car's cabin, the heater will work again. Of course, you can let the engine running a little more, just to be safe, but that is it. After that, still carefully flush the system and rinse it by putting hot clean demineralized water inside. And finally you put the antifreeze in and that is it.
It really works and is the only solution that I've heard of that works. The alternative is to replace the heater, but that is a lot of work and is no need for that.
I had the problem for about 3 winters and in the 3rd one, when I've cleaned the heater I was reluctant to believe that this will work after I tried the years before all kind of other solutions to clean it. But this really works and the heat inside the car is really really nice since I've performed the cleaning!

 

[wellu]

Now i get it, citric acid. That wont do anything to the aluminium-heater matrix? I've been wondering that it would definetely work but haven't found any information that will it destroy my heater matrix completely.

But if it worket with your punto (even after several attemps with commercial products), i will try that.

 

[Mike1alike]

No, citric acid doesn't do anything bad to aluminum nor to any other component of the cooling system.
People tested it and have reached to this conclusion. I got this working method from an Opel forum and the man that posted it came back after 9 years and said that heat in his car still works great and in fact it works better than in his other newest car and he should make time to clean the heater and cooling system in the new car as well.
Good luck to you and I am certain that it will work at yours, too and you will have a heated inside of the car again and a working heater, fully functional!

 

[Mike1alike]

I'm expecting warm news from you, Wellu, hot even!

 

[wellu]

Okay, yesterday i planned to go at the garage to flush heater again with citric acid. It was -23°C/-9°F here so i planned to install a block heater to heater return hose also.

I went to the parking lot and started the car - started barely (weak battery). After maybe 30 seconds of idling i heard "BEEB BEEB BEEB" and engine stopped with text "check engine" and a red engine light. Started again and light turned to yellow. Openet hood and check that is everything alright....well not...

Radiator's had enought of freezing temperatures and had leaked the reservoir empy. There was still coolant in the system so i managed to drive at work, where "my garage" is.

I runned leak fix trought radiator (blocked heater hose before this) and after that flushed the whole system. Because i had to be careful with radiator now, i boiled some water and poured that with citric acid straight to heater hose (and wrong way around). After that i waited 30-40 minutes before started flushing the system again.

Something pretty dark and slimy came out from the heater, but after maybe two minutes of flushing the water that came out was clear. I still continued flushing the whole system for about an hour. Water that i used for flushing was +60°C/140°F

Then installed the hose-heater, connected all the hoselines and put coolant in. With bleeding i was carefull and runned the engine something like 15 minutes, changing rpms betweed idle-3000-4500. It was blowing hot air and nothing was leaking - great!

During the fixing and flushing, temperature outside had dropped around -25°C/-13°F. This is so cold that very few cars are warm anymore. When engine reached normal running temperature, air that is coming from dash vents was between 40-45°C. It's managable thus rear windows stay frozen. When i measured the temps before (in this thread), outside temp was -7°C so something has happened. When stationary revving the engine hard, i can get +60°C air to the cabin.

I think that the heater is working as good as it can. If i idle or city-drive, enigne temps start to drop if fan is at speed 3 or 4. Heater is then cooling the engine "too much" to keep temperature up. So i think that this is so called "case closed" with this stilo.

Now i have to figure out a way to change the radiator, because it's leaking again (not much but enought). Only pain-in-the-ass with it is those hose connectors. After 17 years of sitting tightly they wont open i'm pretty sure. If i only could find a radiator with normal hose connectors, i'd be more than happy...

 

[wellu]

This topic came back to my mind today and i was thinking that maybe i'll write the wrapup about this winter.

So, radiator held up pretty good almost whole december, but at the dec. 23 (day before christmas) it blow. Leaked all of the coolant straight out from reservoir.

So, i changed the radiator between christmas and new year and it has worked fine after that. Actually it felt like that heater worked better after the replacement of the radiator. Maybe there was a leak all this time and cooling system wasn't pressurised properly? Anyway, at -25°C temperatures it was still warm inside without any frostbites. So i'll call this operation a success.

If anyone is wondering about changing the radiator, i'd say that it's pretty easy job. I had the car on ramps, bolted the underside's plastic plank away, disconnected the hoses and dropped the old radiator downwards. New went in from bottom up, then cleaned the hose-connectors with silicone-based lubricant and connected them. Didn't have any problems with those connectors allthought it's good to have a large enought pliers for removing them. I used large adjustable pliers that i used to press the metal-klips that are locking the hose connector to it's place. Then just carefully tapped those pliers with hammer to disconnect the hose-radiator assembly.

 

[wellu]

Hello! I'm back with the same topic "Stilo heating and fogging issues".
As I said before, the heater was powerful enough (I'd say semi-ok when compared to Marea or Bravo/-a mk1) for winter driving that I didn't get any frostbites or feel uncomfortably inside the cabin on longer journeys. But there was still a problem with fogging windows (this seems to be some kind of typical issue with Stilo M.W. if you search it via google) and this was a problem in the summer also (use of AC helps, but it won't completely remove the fog from rear windows). I was planning to do air ducts from the centre console to the rear windows, but then I noticed that the air passages/vents from the cabin to the air exit vents behind the rear bumper were fake!
I mean these:

So I took the interior of the trunk apart and found that those fake vents were actually removable pieces of plastic. It was attached with plastic "nails" or clips, which were melted to prevent opening them. Ok, brute force with a small flat driver solved that problem and I got those grills removed.

Vents were just like they should be open, but they were not. I decided to open them with a gas-powered soldering iron that had the scalpel attached to it. But, then I ran out of gas and didn't have any in reserve. I tried different knives and even a chisel with a hammer, but with no success... So, I went with the angle grinder.

After opening that vent from both sides, I put the interior of the trunk back together and this is the result:

I also found some foam blocking the exit air vents from both sides of the trunk:

That piece of foam was straightly in front of that vent, blocking it completely on both sides...

There haven't been any "real tests" yet (rainy day and four people on board) but it feels like the cabin would heat a little bit easier and faster. Waiting those sub-zero temperatures and snow, it will tell if there is any difference.

I was thinking that this "discovery" might help someone with foggy Stilo M.W., although I'm not sure if this is a common issue or just a random production quality-related thing.