| Many people are rightly skeptical of coolant system additives - there are a lot of myths in the automotive industry. Luckily, the coolant system additives are in the category of good practice, for reasons I'll explain here. It all begins with chemistry. Like today's modern oils, many of today's modern coolants incorporate some of the chemicals that help cooling and increase heat flow around your cooling system components. As more and more automotive components are made out of aluminum, and radiators become smaller, the use of these additives becomes more advantageous.|
Aftermarket coolant system additives are known as surfactants. What is a surfactant? A surfactant or surface active agent, is a molecule that has a water-loving end (hydrophilic and water fearing end (hydrophobic). Localized boiling of coolant in the cylinder head can create large shock waves that can wreck havoc on your engine, particularly on aluminum components. Without going into too much boring detail, these surfactants also help to reduce the amount of air in the cooling system, and also control the amount of foam within the system.
In general, there are three main reasons why using these additives is beneficial to your cooling system. Firstly, they reduce harmful cavitations and foaming that may occur when your water pump is kicking out fluid at a rapid pace. This reduced foaming helps to prevent damage to aluminum surfaces. Secondly, the use of these additives aid in the transmission of heat from the coolant to the radiating surfaces within the radiator. Even if your car runs very cool, these additives add a extra level of protection in case a thermostat or similar component fails. Thirdly, the additives contain corrosion inhibitors. Most cars on the road have cooling systems that do not contain the ideal 50/50 water / antifreeze ratio that the antifreeze manufacturers design for. The additives help to minimize potential corrosion by maintaining adequate pH levels. Even if your antifreeze already contains surfactant additives, the use of these additional additives is typically beneficial because most cars are shortchanged on the 50/50 coolant/water mix.
In general, the benefits of additives like Water Wetter are:
- Reduces corrosion due to rust, and electrolysis
- Increases the 'wetting ability' of water and improves heat transfer, thus reducing cylinder head temperatures
- Cleans and lubricates coolant system seals like those found in the water pump
- Reduces the formation of foam and cavitations which can cause corrosion
- Reduces the effects of 'hard water' in the cooling system
In general, the addition of these additives is cheap, and it's a proven benefit too - no snake oil here. Using the additives on a perfectly maintained car can also provide a significant margin of error in case something goes wrong. BMWs in particular are infamous for cooling system failures - keeping the odds on your side can prevent a costly head gasket replacement.
Your car will lose a little bit of coolant here and there over time due to evaporation from the reservoir. However, a significant loss of coolant over a very short period of time almost certainly signifies a leak in the system. Sometimes a leak can be seen when you park the car overnight. Often the coolant leaks out and then evaporates while you're driving, leaving no tell-tale mark of coolant on the pavement. If you suspect a coolant leak, visually inspect all of the hoses, the water pump, the reservoir, and the radiator for seepage or the 'weeping' of coolant out of seams and gaskets. Check the seal on the radiator cap. Check that the radiator cap is fastened securely - the way the BMW radiator cap is designed makes it easy to make the simple, yet deadly mistake of leaving the cap cocked - allowing coolant to leak out when the engine is running. If you suspect a leak that you cannot see, a pressure test from a professional mechanic can verify the integrity of your system.
If you can't find any visible leaks and the system appears to hold pressure, then check to make sure that the cap is good, and is rated for the proper pressure. Verify that the cap you have for your car is the proper one for your engine.
If the system does not hold pressure, and you're still at a loss where coolant might be disappearing to, then you might want to start looking in the oil. A faulty head gasket will often cause coolant to leak into the oil. If you remove your oil cap and find a yellow murky substance, then you probably have a faulty head gasket. The oil level may be elevated and you will be able to see droplets of coolant inside the oil filler hole. If coolant is leaking past the gasket into a combustion chamber, you will see steam exiting out of the tailpipe, and the spark plugs will foul easily. In addition, the exhaust will be contaminated with the silicate corrosion inhibitors found in the coolant, and your oxygen sensor will be destroyed - plan on replacing it if you have experienced this problem.
If you can't discover what happened to the coolant, it may be because there was a temporary overheating problem and some of the coolant boiled over. In this case, top off the coolant and keep a very close eye on it. It's not uncommon for overheating issues to suddenly destroy a head gasket.
Well, that's all for this week, stay tuned for the next topic!
Thanks again for your support!
Wayne R. Dempsey
Principal Owner of DriveWerks
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