Changing the antifreeze/coolant

facade wrote: tbh, anti-freeze lasts pretty much forever, it is the anti-corrosion additives that get used up, so renewing 75% of the antifreeze should be fine.

I tend to go this route, Being lazy about antifreeze I just work out how much is needed to get the ratio right for the whole system, suck out what is needed to make room and pour neat in.

Someone would probably comment "well just use concentrated coolant and control your own mix". I would gladly, but almost all Japanese engines require coolant chemistries which are specific to them and quite contradictory to most European coolants, and having anything Japanese in my country is like having a space ship. It can be quite an endeavor to find ordinary parts for Japanese cars, let alone dedicated coolants. The only Japanese-suitable coolants (non-silicated, phosphated OAT coolant types) which I can find here are already pre-mixed, no concentrates.

My Junior was the most awkward to get information about being JDM only but my other Japanese imported cars Pajeros, Rav4 etc. (Ie, spaceships) were no problem I suppose because there are UK equivalents here. Maybe I am a Philistine (anti intellectual I confess) but I just use whatever is on the shelves.

I figured out the same solution for the issue of getting a diluted final mix when doing the final pouring with an already 50/50 pre-mixed coolant.

The simplest solution is to drive for a day or two with that (so that the newly poured 50/50 pre-mixed coolant mixes with remaining water in the system), and then drain out a liter or two of that mix and fill the missing part with more 50/50 pre-mixed coolant. This should bring the total mix closer to the 50/50 ratio, probably somewhere around 40/60 (coolant/water).
This is not ideal solution, and it wastes pre-mixed coolant, but it is at least dead simple.


I have just one remaining concern when flushing:
The manual does say that the system should be flushed with (preferably distilled) water in a few iterations, until clear water drains out. It says that in each iteration, you need to pour water in the radiator, run the engine until the top radiator hose (and thus the cooling system) get hot, stop the engine, drain. Then refill a new load of water and repeat the iteration.

Now, I am worried if pouring cold new water in a hot empty radiator is healthy for the radiator? It will produce sudden temperature shock changes, and I don't thank that any metal, plastic and rubber parts of the cooling system like such shocks! But on the other hand, I certainly don't fancy pre-heating the water on a stove !!

kirkynut wrote:
Job done. Have a cup of tea and a Hob Nob.

Kirkynut

Nice and easy.

I see a few of you mentioning 50/50 of coolant/water ? Water is the coolant? The anti freeze is not a coolant, just a corrosion inhibitor and an anti freeze. The best conductor of heat is water, nothing beats it !

kirkynut wrote: I think modern anti-freeze is a bit different and they are now coolants too.Kirkynut

Yes we had dedicated antifreeze coolants back in something like the 1980s and I wish I could remember the name.

I performed the coolant flush and replacement myself a few days ago, with a side help from an old retired mechanic.

It was indeed a major hassle to perform it.

The major issue was getting it all out. The factory specifications say that Jimnys with M13A VVT petrol engine have coolant system capacity of 5,9 liters.
Therefore, I expected at least 5 liters to come out during draining. I followed the coolant draining / flushing instructions written here by Facade, which are essentially the same instructions as written in the original factory service manual.

The instructions essentially say to open the top radiator fill plug, run the engine with cabin heating on until the upper hose between the engine block and the radiator becomes hot, indicating that the thermostat is open and that the coolant is flowing through the entire system. Then stop the engine and open the drain plug in the bottom of the radiator to drain the coolant.

I did exactly that, but only about 3,5 l of liquid came out. I poured in 3,5 l of distilled water in the radiator (as no more could fit in) and ran the engine again until the upper hose became hot again . I drained the system again, and I got only 3,5 l again.

I then noticed that the lower hose between the radiator and the engine block is completely cold, and found that to be strange. No matter how much I throttled the engine in place, the lower hose would not warm up. I then got frustrated, and took the car out on a very hard ride for a couple of kilometers, all in first gear. I woke up everyone along the way who was still asleep on that Sunday morning.

When I returned to the garage, the engine bay was hot like an Egyptian crossroad in a summer traffic jam. I quickly positioned the car over a canal, turned the engine off and drained the cooling system. This time the lower hose was hot too, and this time I got more liquid out - only 4 l in total !

So at this time I basically gave up.
Either I am an idiot who can't drain a simple piping system, or the factory capacity specifications are wrong and the system's actual capacity is only around 4 l, or the thermostat is extremely high-sensitive, closing as soon as the coolant temperature already drops from 90 C to say 85 C, thus not allowing enough time for all the hot coolant to drain out.

I poured around 4 l of new pre-mixed OEM Mazda FL22 phosphate-based coolant (the same exotic Japanese type that Suzuki specifies), and went to do something more straightforward in my life, like cleaning the toilet. Damn Japanese spaceships. Servicing a late 1990s Volkswagen is like baking an egg compared to this.

Bosanek wrote: I performed the coolant flush and It was indeed a major hassle to perform it.

The major issue was getting it all out.
So at this time I basically gave up.and went to do something more straightforward in my life, like cleaning the toilet. Damn Japanese spaceships. Servicing a late 1990s Volkswagen is like baking an egg compared to this.

Oh dear what a palaver. This is why I said to just add a bit of neat antifreeze. I often just literally syphon out some water (or whatever is in the rad) from the filler cap orifice on the radiator and replace it till topped up with neat antifreeze. Hopefully there was some sort of antifreeze in there anyway and if not "rinse and repeat" as they say (it's an expression meaning do it over and over) till you feel satisfied.

As far as circulating is concerned there is a bypass hole in the 'stat which allows circulation (usually lol) and sometimes a hotter 'stat might mean the engine has to be ....er............hot to open the thermostat. If the radiator is doing a great job the bottom hose should be somewhat cooler.

I found the Jimny to be pretty much basic technology especially compared to a spaceship - worked on them for years, spaceships I mean........naw just joshing.
www.gifs-paradise.com/animations/animate...-blue-lights-012.gif

For me the best reason for antifreeze is to avoid corrosion and frankly I often don't use it cos it makes for leaks in some of my motors but hey, if you are going to the south pole in the car then better get some in!

I didn't find this to be an issue at all to be honest, I just did what it said in the manual.

Drained the coolant by the drain tap (agreed it does leave about 1 ltr in the system), but then filled with water, run to temp, drain and repeat until it runs clear. It was running clear on the third drain. Refill system with Halfords OAT (pink), 1ltr concentrate to allow for water in system, the rest 50/50 mix OAT and Deionized water, so resultant mix will be 50/50. Run to temp, allow to cool and top up to levels if required.

Just as my manual said, no issues, no problems.

The most amount of time was spent looking for the correct antifreeze type. After much cross referencing of the various web site system, my data base at work (Halfords) and the datasheets for the various recommended antifreezes manufacturers, they all turned out to be ethylene glycol based antifreeze with the OAT anti corrosion pack additive. Or in simple terms the pink OAT stuff that halfords sells. (Also available in other shops). Just for those that want to know this is a 2009 M13A VVT engine.