Seicento 900 (2002) - Flushing Refrigeration System, Thermostat Replacement, & Maintenance Insights

I will exchange the refrigerant in the nine hundred council, along with the replacement of the thermostat. Unfortunately, the car is a little run down, my father bought it three years ago (car year 2002, mileage 90,000, currently over 100) and since then he has only changed engine oil with filter. Although the car had several owners and the closer history is unknown, it is in a fairly decent condition. The engine has quite a good kick for 900, even in three people plus luggage. I do not know how the condition of the gasket under the head, the oil disappears a little but the pipe does not kick (only when cold is a little white), probably due to leaks whose mass - apparently normal in this engine. Even pouring under the gasket under the valve cover, mentioned two years ago because it was pouring However, the coolant does not decrease at all, we have not even added a drop from the purchase and the condition is still there (no wonder the eye type does not float from oil, so rather upg is fine at least on the cooling system side).

After this short exposure with which car I am dealing with, I would like to ask if it is worth flushing the cooling system before pouring new liquid. I'm not going to use any rinses or descaling agents, I've heard that it can do more harm than good. Basically, the cooling works well, the engine does not overheat, only the thermostat does not hold and the engine catches the temperature for a very long time, which burns a lot in the winter for short distances, not to mention heating the interior. Heating generally works well, when the engine is already hot it heats like hell, but at low revs the heating power decreases. It is enough to raise the turnover even a bit (on the ear 1100-1200) and it's ok, I don't know, maybe it should be like that in this model.

So basically the cooling system works fine, but looking into the tank is not optimistic. It looks as if the coolant was brown, like dissolved faeces. When you draw into the syringe, or detach the thin hose that goes from the throttle to the reservoir, you can see that the fluid is not that bad. It has a slightly green color, but you can see that a lot of water had to go there. Nevertheless, as there have been great frosts during the last winters (the car sleeps under the cloud), it never happened that the liquid froze. However, looking at what I see in the tank, I wonder if it would be worth doing something like this: Pour the system with plain water, ride for a few days, then drain it all and only pour new liquid. If the muck continues to spill out, pour water over it a few days, before pouring it with liquid. Is it worth doing something or is it just a waste of time? Theoretically, probably nothing should happen if I do not, but somehow it will be stupid for me to pour new liquid into the sludge system, in which some sludge may flow. What will you do?

Best wishes.

wojtek1234321 wrote:

This brown color of the coolant may also indicate that normal water was used instead of the coolant in previous use.

I can't rule it out, the car had several owners and damn knows what they were doing there. However, the brown sediment is only in the tank, the liquid is quite transparent, with only a slight green tint. However, the liquid itself is not red, brown or brown. I specially pulled a bit into the syringe to see it, I also allowed myself to detach this small hose that drains fluid from the throttle heating circuit, after firing the engine fluid was just slightly green. Probably a lot of water was added there, however, as it was freezing cold in recent years, it did not think to freeze.

Thanks for advice. In that case, I decided to flush the system with running water from a garden hose before flooding with fresh liquid, additionally I will unplug the heater hoses and overflow it several times changing the direction of flow. When clean water comes out, I will finish rinsing it, wait for everything to flow and pour liquid. I think to disconnect the hose going to the water pump, where is the last tee connecting the hoses from the heater and radiator and pour water from the hose (i.e. to the pump). It seems to be the best this way, because clean water will pour into the pump, and I would not like to pour it in so that it can be replaced soon. On the other hand, the muck before it leaves the system will pass through the radiator hmm ... In general, I will see what comes out after pouring out the current liquid, if no sludge or other suspensions appear, then flushing will let go.