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Charge Cooler Fluid Change

Mod Details
PremiumNo Difficulty Mod ID1753 Creditevilution For452 Roadster Link Copy to Clipboard

This probably isn’t the information you think it is. However, it’s more important.

How Do I Drain The Charge Cooler System?

See, this is the information you thought was going to be here but really, it’s not. All you have to do is take a pipe off the charge cooler radiator in the engine bay near the front of the engine. Wait until the coolant stops flowing and refit the hose. There’s no problem turning the ignition on for 10 seconds so the charge cooler pump helps remove the coolant. Just don’t run the pump dry for longer than necessary. Securely refit the hose.

If you want to do me a favour and snap some photos, I’ll add them to the site.

How Do I Fill The Charge Cooler System?

Open the charge cooler cap and pour in the coolant mixture. The correct coolant and mixing ratio can be found here.

How Often Should I Do A Fluid Change?

Great, we’re finally onto the crux of the issue. Very few people do a fluid change ever on their charge cooler system.

Why should they? The anti freezing properties don’t wear out and the coolant doesn’t get that hot, so why bother?

Coolant is a mixture of 3 things.
Water for cooling.
Glycol to lower the freezing point.
Nitrate, Phosphate, Silicate and Sodium Benzoate to reduce internal corrosion.

It’s the last part that’s the problem. Anti corrosion additives wear out. They fight corrosion up until the point where they don’t.

If you don’t regularly change the coolant, you will start getting unseen internal corrosion in your charge cooler system.

Is That Bad?

It’s taken 20 years for people to start finding out but yes, it’s bad. This will become more of a common problem over time.

The issue is that the charge cooler flows water through a radiator to cool air coming into the engine. The radiator corrodes and eventually a hole appears.

Since the charge cooler fluid is warm, the fluid expands, creating its own system pressure which aids the release of the coolant into the air inlet of the engine.

What Happens If Coolant Gets In The Engine?

Coolant loss, increased engine compression, excessive smoke, possible catalytic converter damage and pump damage when the coolant runs out.

Here’s a nice example sent in by Ben C from SmartTechnic. The system is being manually pressurised to highlight the coolant loss.

It goes without saying that a replacement charge cooler isn’t cheap and who knows how long they’ll be available for!


So, for the sake of your wallet, consider changing the coolant in the charge cooler system every 3 years. If the fluid is low, don’t just top it up with water. It’ll save you having to buy a new charge cooler and eventually buying a new pump that has also corroded.

General Information

People seem to think that a coolant mixture will boil at a higher temperature than pure water. This is not the case. The increased boiling point is due to the pressure in the system. Water is a better cooler than coolant mix and has a higher boiling point than a coolant mix. Coolant mix is purely to stop it freezing and to install anti corrosion additives.

Don’t use deionised water in your coolant mix. To maintain an equilibrium, it strips ions from metals and the anti corrosion additives.
Distilled water is better than tap water or demineralised water. Cheap bottled drinking water is the best option all around. Obviously avoid putting the finest flavoured Evian water in there. Your charge cooler isn’t going to appreciate cucumber flavoured water.