Now our Canadian brethren or people from Buffalo, NY might be the exception, but for most of us Summer get's HOT. Here in Alabama it averages 92 degrees with 100% humidity from May till October. That kind of heat can wear down a car faster than you might think. And it can really wreak havoc on a BMW. Now I love my BMW, with 180k miles it still out drives most new cars. But why, oh why, did they see fit to put plastic in all the major components of the cooling system? This engineering mistake is even more mind blowing when you consider that most modern BMW's have an all aluminum motor. Effecient? Yes. Light weight? Sure. Prone to warp faster than a politician when overheated? You bet! How do you avoid this dastardly fate? Keep reading, I'll tell you....
Do you know how many times I see on the BMW forums that someone overheated their car and they had to replace the motor at a cost of $5-$14k dollars? More than I care to remember. This is an avoidable mistake. As your doctor always said, an ounce of prevention is worth $14,000 worth of saved money (or something like that).
The reality is that your A/C running full blast (I will cover how to maintain your A/C in my next post), sitting in beach traffic in 90 degree heat will "help" you uncover any weak point in your cooling system. And most people try and limp the car home or drive it to a safe place before turning off the car. With a BMW if you do that, I can assure you a $6000 or higher repair bill. Make sure that you and anyone who drives your car understands to turn the car off the moment they see the little red light. This is not optional!
But why not avoid the above scenario altogether? Here is how to get piece of mind for relatively low cost:
1. Check your coolant level weekly. Please do this when the car is cold to avoid third degree burns. The lilttle float should be sticking up past the top of your resevoir, if it isn't, add some antifreeze.
2. Replace your major cooling system parts. Change them BEFORE they break. If your car has 60k miles on it or more, this means YOU! Parts list includes:
- water pump ($50, DO NOT buy the one with a plastic impeller, they break, ask me how I know)
- thermostat ($60)
- expansion tank ($55)
- upper radiator hose ($23)
- lower radiator hose ($30)
- both drive belts ($50)
Overhauling the BMW cooling system is NOT hard to do yourself. There are about 100 DIY guides on the web showing what to do (see videos on the you tube bar to the right of this article).
3. Inspect your fan clutch (automatic), fan blades, and radiator. Make sure they are clean, not nicked or cut, and look like they are in decent shape. (Hint: your radiator collects a fair amount of crap between it and the A/C condensor, it wouldn't hurt to pull it out and clean it off with water, but do NOT scrub the fins of your radiator. They will bend and you will damage it).
4. Use Redline Water Wetter or similar product. These products have been tested and proven to lower temps as much as 10 degrees. This makes a big difference.
5. Keep your oil fresh. Most BMW purists change the oil every 7500 miles. In the summer you could do it every 6000 miles for added protection. A well lubricated motor creates less fritction, less friction means less heat. (also might want to consider a heavier weight oil for the summer on higher mileage cars over 100k).
Also, if your car has between 130k-150k miles on it, you should go ahead and replace the radiator. You can get them for less than $200 at radiators.com. Another good idea, if you have an automatic, is to replace the auto transmission thermostat ($60). It will almost always break when you remove the expansion tank and even if it doesn't break, if you re-use it and it fails it will kill an expensive transmission.So think about it this way, for $268-528 ($528 includes radiator, and trans thermostat) you can avoid $6000-$14,000 in repair costs. I'd say that is a pretty good trade off. Not to mention you won't have to deal with being stranded with an overheated car, have to deal with a tow truck, or miss work.