Case Studies

An Ounce Of Prevention – Antifreeze and Coolant Service

The Importance Of Antifreeze/Coolant Service
Take a look at these photos, notice the brown areas of clogging and material at the bottom of the radiator? Nowhere is this more frequent than on engines using an aluminum cylinder head, and cast iron block…like most modern cars.

And we also find this clogging not just in radiators, but also in heater cores. A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle’s engine is passed through a winding tube of the core.
Fins attached to the core tubes serve to increase surface for heat transfer to air that is forced past them, by a fan, thereby heating the passenger compartment. A clogged heater core will provide low or no heat when needed in cold weather.

Not Just Audi
We should mention that this is not just an Audi problem, we find in BMW, Mercedes, Land Rover, Mini Cooper, Volvo, as well as in Japanese autos. The good news is that you can prevent this, before it happens, before your car overheats, before the breakdown, tow in, and possible engine damage.  We have more information about the problem below, the cause and then correction, so read on.

The Problem

The engine radiator is used to remove the heat from the engine. Hot coolant from the vehicle’s engine is passed through a winding tube of the core. Fins attached to the core tubes serve to increase surface for heat transfer to surface air that is forced past them, by a fan, thereby taking heat away from off the engine coolant.

Clogging of the tubes may occur if the coolant system is not flushed or if the coolant is not changed regularly. If clogging occurs the radiator will not work properly. If coolant flow is restricted, heat exchange capacity will be reduced or even lost altogether if the radiator core becomes blocked. You can see from the the photos this core was fully 1/3 blocked, doesn’t make for good cooling, leading to engine running hot, overheating, and possible engine damage or failure.

Why It Happens
From an Audi Technical Service Bulletin – Excess flux from the aluminum cooling system components contaminates the cooling system. This over time causes a high acidic concentration in the coolant. The result is oxide particles (aluminum rust) and excess flux restricting the engine radiator and heater core.

Electrolysis – Another failure mode, somewhat associated with the above, is dirty coolant is known as electrolysis. Electrolysis occurs when stray electrical current routes itself through the engine coolant.

The electricity is attempting to find the shortest path, and impurities in the coolant often generate a path of least resistance that the electricity travels across. In particular, electrolysis affects primarily aluminum engine components, resulting in pitting and scarring of the aluminum surface. This eating away of the metal can cause coolant system leaks, and in particular, radiator leaks around aluminum welds. While cast-iron components are also vulnerable, typically the aluminum metal parts fail first. So change that coolant!

Sounds simple, right? Yet one of the most neglected task on many newer cars is the maintenance of the cooling system. Today’s high tech cars often come with so-called “lifetime” coolant, promising extremely extended coolant intervals. The problem is, these intervals come at a cost, expensive engine damage down the road. In general, it’s recommended that you flush and clean out your cooling system once every 36 months, or approximately every three years.

The best way to protect your engine, and ultimately, your wallet or pocketbook, is to make certain your car’s coolant is flushed at least every 3 years, shorter if it is a vehicle that sits for an extended time. Fall time is ideal to ask your service facility about your vehicle’s coolant. Our goal is always to prevent, rather than just repair problems.

At Atlantic Motorcar, we’re all about providing our customers not only Great Service but also Value. We understand that “An ounce of prevention is worth a pound of cure.” (my mom, a nurse, would be proud I remembered that.), in other words, preventing, or catching problems like this early, can save you more than just money.

Questions, or if we can be of help in any way with service on your Audi, BMW, Mercedes, Mini Cooper or other European (and now Japanese) import, please contact us. Our team of Service Specialists is here to help, for even the newest autos! (207) 882-9969.

Knowing, not just “doing”, that’s the Atlantic Motorcar Center way.

The Atlantic Motorcar Center Service Team


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