What a Colorado winter leaves behind on your car: magnesium chloride residue, pothole damage, alignment problems and worn wipers. A spring checklist for import owners, with the jobs to ask a shop about.
By April, most Colorado cars have spent months coated in road treatment and slamming through potholes that opened up during the freeze-thaw cycle. Here's what to look at once the snow is mostly done.
Wash off the deicer, especially underneath
CDOT treats state highways with salt-based deicers that have corrosion inhibitors in them. Its solid product is a mix of salt and magnesium chloride, and it uses liquid magnesium chloride when it gets really cold. Even so, the residue that ends up on your car is something you want off, especially from the underside, brake parts and wheel wells. A 2002 study done for CDOT looked specifically at how magnesium chloride and sodium chloride corrode car parts, and found magnesium chloride was the harder of the two on bare metals like aluminum and stainless steel when parts went through wet-dry cycles. Painted and coated body panels held up well. See the sources below.
- Get an undercarriage wash a few times over the winter and once in the spring.
- Rinse the wheel wells and the backs of the wheels.
- If you have winter wheels, clean them before you store them.
Pothole damage
Potholes are the other spring tradition. A hard hit can do more than make you swear.
- Bent wheels. Big, low-profile wheels on BMWs, Audis and Mercedes are especially easy to bend. A vibration at highway speed that wasn't there in the fall is a clue.
- Tire bubbles or sidewall bulges. Replace the tire. A bulge can fail without much warning.
- Alignment. If the steering wheel is off-center or the car pulls, get an alignment before it chews through a set of tires.
- Suspension parts. Clunks over bumps, or a car that wanders or shimmies under braking, can mean worn control arms, thrust arms or bushings. Here's what owners paid for BMW 3 Series front thrust arms and control arm bushings.
- CV axles. A torn boot slinging grease, or clicking on tight turns, is the sign. See Subaru front CV axle prices.
Brakes
Sand, grit and winter grime are hard on brake parts. If you heard grinding or squealing over the winter, have the pads and rotors measured. Owner prices: BMW 3 Series, Audi A4, Mercedes C/E-Class, Volvo, Lexus RX/ES.
Swap tires at the right time
If you run winter tires, swap back to summers or all-seasons once the overnight temperatures stay above freezing. Winter rubber wears quickly on warm pavement. In Colorado, that can be later than you'd think. A May snowstorm on the Front Range is not unusual.
The rest of the list
- New wiper blades (winter is hard on them)
- Top off washer fluid
- Check the cabin air filter. It's usually cheap and makes a real difference
- Check the battery if it struggled on cold mornings
- Look at your oil change interval. Lots of short winter trips are hard on oil
Sources
- CDOT: Snow Removal and Safety (deicers and corrosion inhibitors)
- CDOT study (2002): Corrosion Effects of Magnesium Chloride and Sodium Chloride on Automobile Components
General information, not legal advice. Check CDOT and your owner's manual for the rules and specs that apply to you.