Most Up-to-date Coolant Recommendation

[littlemoule]

Hi Guys,

So I realized my 2015 Mirage SE (Manual) is one of those mirage with half heat (clogged up heater core) problem, heating only the driver side. Also, I just passed 200,000 KM so I have the following questions:

1. If the heater core is clogged up, won't the coolant back-flow and not circulate throughout the system? Does mirage give any warning light about engine overheating?
2. Anyone had any success with unclogging the heater core using specialized detergents without replacing the heater core itself?
3. What is the most up to date Engine Coolant Recommendation for the mirage on the forum? And is there any point changing the coolant with a clogged up heater core?

[mohammad]

1. will not back flow. Coolant just flows through only half the heater core. I believe there is also a parallel path for coolant to flow within the engine compartment. Not all coolant goes through the heater core.

2. There are people on the forum that have experimented with this. You can probably search the forum and read about it. Here is a reputable one: https://mirageforum.com/forum/showth...nt-Flush/page6

Additionally there is a replacement heater core that can be installed with less effort than the OEM one: https://mirageforum.com/forum/showth...acement-easier

3. Like oil this is very subjective. I only use OEM coolant. Changing coolant is good preventative maintenance but will not help/fix your heater core issue. Its simply too late for that to work.

[Fummins]

1. Yes there is a red warning light that comes on if you overheat the engine. It's a red thermometer symbol, like the green one that comes on when the engine is cold. And like mohammed said, a plugged heater core won't overheat your engine.
2. I've had half assed luck using drain cleaner in copper heater cores on older vehicles. But they only worked slightly better, not nearly as good as a new one.
3. On the work cars I use what I've used for the last almost 10 years. Just aftermarket premixed blue import coolant that met the mitsu specs. In my own car, it had prestone or some green coolant in it when I bought it. When I replaced the engine I dumped green stuff back into it. Heater works fine in the winter, old engine had zero corrosion in the water jackets but neither did any of the ones I tore down with the blue coolant.

[Top_Fuel]

Anyone had any success with unclogging the heater core...without replacing the heater core itself?

Start reading at THIS post. This guy set up a bucket and used a pump to circulate mineral spirits through the heater core (for several hours). He reported a significant improvement in heat output after doing this.

If my heat ever gets that weak, I'll absolutely try this before I even consider replacing the heater core.

[littlemoule]

Thanks for all the good reply friends.
Okay so as long as it doesn't overheat due to any possibility of backflow I won't worry about it. I did notice that in the THIS post, the OP had some overheating issue because of his clogged up heater core.
I will get the coolant replaced as a preventive maintenance anyway. As for the heater core itself, I won't bother with it - it looks like a big hassle. I might just get some 12v shop to install an electric heater down the road if I really need it.

[mohammad]

Thanks for all the good reply friends.
Okay so as long as it doesn't overheat due to any possibility of backflow I won't worry about it. I did notice that in the THIS post, the OP had some overheating issue because of his clogged up heater core.
I will get the coolant replaced as a preventive maintenance anyway. As for the heater core itself, I won't bother with it - it looks like a big hassle. I might just get some 12v shop to install an electric heater down the road if I really need it.

The Mirage has a built in electric heater. Fummins made a video on it: https://www.youtube.com/watch?v=JkzmRd2FDso you could probably jump the relay or add a switch to it to force it to stay on.

[littlemoule]

I had no idea electric heating element existed in all mirage. If such is the case, in peak winter times wouldn’t it blow warm at least to begin with? Last winter I didn’t find that to be the case. Also, in the video, there is no mention of where is this located in the mirage. Good idea of seeing into jumping this element if it exists, but I’m not sure if it exists.

[mohammad]

Littlemoule - It is next to/pressed against the heater core. It is part#8 in this diagram. It has a separate relay/fuse box you can check to ensure it's present on your car, it is located near the battery. Some users remove the fuses for the electric heater to improve fuel economy. (A photo of this is shown in the thread below)

I agree that I do not notice warm air when the engine is cold. I imagine some of the heat is likely soaked up by the heater core.

Here is a thread that talks about this: https://mirageforum.com/forum/showth...ment-in-Heater