Coolant Change: How to Replace Engine Coolant

Hello everyone,

In the service booklet for my Ford Galaxy TDI (110 hp, AFN, 105,000 km, purchased used with 90,000 km), it states that the coolant should be changed every 60,000 km or every three years. However, this has not been done yet, and it is not documented in the service booklet.

Among my acquaintances, the prevailing opinion is that this is nonsense. However, I don't want to risk the longevity of my Galaxy just to save about 15 euros on the coolant.

Is there a risk of corrosion within the cooling system if the coolant is never replaced, or is the coolant change just a good business opportunity for authorized workshops?

Thank you for any advice.

The silicate content in the coolant decreases over time because it is added to counteract the oxidation of the aluminum parts and is therefore consumed in the process.

Some metal debris from the water pump's ball bearing can accumulate in the coolant, which is why it's advisable to change the coolant periodically. It's not particularly expensive or time-consuming.

Hi,

Absolutely. In our Audi 80 1Z, the core plugs have rusted through after 270,000 km because we never changed the coolant.

Absolutely! You should definitely replace these components at regular intervals. Otherwise, corrosion can occur. A faulty radiator is annoying enough, but a leaking heating heat exchanger is even more time-consuming and complicated to replace.
Almost all the used cars I've bought so far have only had rusty brown liquid left in them.

'In my car, the original coolant is still in the system (80,000 km), and it still looks nice and blue.'

To my knowledge, only the first scheduled ZR (timing belt) replacement has been performed recently. Then, the entire clutch was replaced because the release bearing was stuck .

Um, excuse me, here's a really dumb question . Is coolant drained during a timing belt replacement and/or a clutch replacement (for assembly reasons)? It's possible that you might need to lift the engine slightly and/or remove hoses that are in the way.

When replacing the water pump, the cooling system is only opened if the water pump needs to be replaced; otherwise, it remains closed.

You're welcome. And what about when replacing the clutch?

Thank you. And what about when changing the clutch?

What does the clutch of a manual transmission have to do with the cooling system? Are you really asking that question seriously?

Good evening.

H.R. Etzold writes in "How it's done / Skoda Octavia":

The coolant with the G12 concentrate (recognizable by its pink color) only needs to be replaced after repairs to the cooling system, and only if the coolant was drained during the repair. A coolant change as part of routine maintenance is only intended for vehicles filled with G11 coolant (blue-green color).

He also suggests that G11 can be replaced with G12 (thoroughly flush the cooling system). Under no circumstances should G11 be mixed with G12 (brown color).

It seems like this G12 is a great product.

mcgregg

@Julian: The forum is also for learning. I have only replaced the clutch in vehicles without coolant so far (like a Trabant). However, I know that you often have to remove interfering components: cables, hoses, etc.

It's quite possible that, for example, a coolant hose could interfere with the installation or removal of the coupling. If you remove it, you'll be opening the cooling system.

Therefore, I am asking a question that I am very serious about.

Hello!

I've received advice from various Volkswagen experts against replacing G11 coolant with G12, as not all engines are compatible with G12. They mentioned rubber hoses that might deteriorate due to G12, among other things. I'm wondering if there's any truth to that. Also, I'm curious whether the temperature range of G11 is the same as that of G12 (i.e., whether the boiling point is higher with G12?).

Regards, Peter.

...and now there are no G11 or G12 models anymore!

The newest product is called G12+, and it is miscible with both previous versions!

m;

Hello everyone,

Thank you for the tips.

Okay, so I will buy the required amount of G12+ (4.5 liters), drain the used coolant, refill with water, and let the engine run for a few minutes. Then, I will drain it again and fill it with the G12+ mixture. I will let the engine cool down in between, or pre-warm the coolant slightly, to avoid exposing it to extreme heat or cold.

In addition, I will test the compatibility of the used coolant by mixing a small amount with G12+. This is in case there is too much of the old coolant remaining in the system.

I hope that the cooling system will drain relatively completely if you open both sides of the thermostat.

Best regards, Ferdl.

Naja die Wasserspülung kannst Du Dir sparen. It doesn't really achieve much.

But:
Do this with a cold engine and do not warm anything up beforehand! Otherwise, you will get incorrect filling amounts.

Drain the coolant, then add the correct mixture until it reaches the MAX line. Next, run the engine at a slightly higher RPM until the cooling fan turns on and the thermostat opens. Then, turn off the engine and let it cool down completely. Finally, top up the coolant with the cold coolant until it reaches the MAX line.

Always check the fluid level during the warm-up phase and refill if necessary.

Naja die Wasserspülung kannst Du Dir sparen. It doesn't really achieve much.


I've never done that with a TDI, but I have with our generators! The stuff that comes out is unbelievable. These engines are 4.0-liter, 4-cylinder diesel engines from MWM (?). They get new coolant every 2 years.

'I recently had a machine that was constantly overheating, and during troubleshooting, I ended up cleaning the entire cooling system. This involved disassembling the entire cooling circuit and then flushing it out with a Gardena hose!'

The clear water turned brown after I got out.

So, it turns out that this kind of rinse actually does something!

Regards,

Manuel.