The Importance Of Cooling System Service In BMW Models
BMW’s trademark combination of high performance engines and rear-wheel drive have made them a firm favorite among driving enthusiasts. While there is plenty of information out there surrounding BMW Service tasks like engine crank bearings, VANOS, turbo, and oil starvation issues, the one vital engine system that is rarely spoken about is cooling.
Let’s dive into the importance of keeping your BMW coolant system serviced, some of the cooling repair issues we see.
The Importance of a Well Serviced Cooling System
One of the biggest challenges when building an engine is temperature. An engine that’s too cold, won’t be properly lubricated and will have issues running or experience reduced performance. An engine that’s overheating can also experience reduced performance, but can also lead to melted bearings and pistons, warped cylinder heads,blown gaskets, and ultimately complete engine failure. Fortunately in Florida, we only have to worry about the latter.
A well maintained coolant system will make sure your BMW gets up to temperature quickly, but more importantly stays within the 212F to 145F sweet spot.
What Does a BMW Cooling System Service Entail?
There are multiple parts and components that make up your BMW coolant system, with several wear items that need to be monitored and replaced. These are as follows:
Coolant or Anti-Freeze
Coolant and antifreeze are used interchangeably, as a good quality coolant will have the same properties as a traditional anti-Freeze. Coolant, like oil, degrades and gets dirty as it is used. We recommend using BMW HT12 green coolant, the main reason is HT12 has a higher temperature capacity and boiling point than straight water, which means it is more effective at transferring heat.
Secondly, HT12 contains a silicate additive that coasts the metal parts of our engine, preventing contamination and corrosion as well as offering lubrication to moving parts like your coolant pump and thermostat.
Coolant should be replaced every 2 years to ensure the silicate coating does not break down or deteriorate. Every time you replace your coolant, the entire system should be flushed to ensure no old coolant is left behind.
Gaskets
There are two main gaskets on every BMW that we need to keep an eye on in regards to cooling. The water pump gasket and head gasket. The water pump gasket is pretty self explanatory. It’s the gasket that sits between your engine block and coolant pump, and helps make a water tight seal to prevent any leaks.
Similarly the head gasket makes an air tight seal between the engine block and head to prevent any exhaust gasses from escaping. The second task it has is sealing the connection between the coolant jackets in the engine block to those in the head, again to ensure no coolant leaks out and into a cylinder.
Coolant Pump and Thermostat
A seized coolant pump or thermostat is one of the quickest ways an engine can overheat. If the coolant isn’t allowed to flow between the engine and radiator, no heat is being transferred from the engine to the radiator and no cooling occurs. Two of the three culprits for coolant not flowing is the coolant pump and the thermostat.
A thermostat’s main job is blocking the flow of coolant to allow the engine to heat up to operating temperature and open to allow coolant to flow once it has. If it gets stuck in the closed position, no coolant flows and your engine overheats. There is no early warning sign for either of these components failing, but the moment you see your temperature gauge creep above normal, have both components inspected.
Radiator and Hoses
While the least likely culprit in an overheating BMW, we still see failures, especially in units with plastic end caps. The radiator cools the hot coolant by allowing the heat to dissipate into air through fins. The main way radiators fail is by blockage, dirt build up preventing dissipation and a drop in system pressure.
Common Causes of Cooling System Failure in BMWs
Ultimately, the biggest cause of engine cooling systems is plastic. Since the early 2000s, BMW has made the move into using more and more plastic in their cooling systems. Transfer pipes that were once aluminum are now plastic, and with exposure to repeated heat cycles, become brittle and crack.
Fortunately for high performance enthusiasts, there are aftermarket solutions that replace these plastic components with aluminum alternatives.
BMW Repair and Service Center In Pompano Beach
While we hope your BMW never leaves you stranded on the side of the road, we do have some extra tips to help Your BMW survive an overheating incident. Once you have, make sure you bring your BMW to Foreign Affairs Motorsport, to get your ride rolling again and ensure you never get stuck again.
With over 30 years of experience working on all things Euro, there is no one better suited to keep your Beemer maintained, or if you’re so inclined, make sure your BMW never overheats as you modify it for more power and performance. Should you have any questions, or want to get your car booked in, contact us today on 954-746-0488.