What the first hard freeze does to a German car in Lexington

The first hard freeze in Lexington can make a BMW, Mercedes, Audi, Volkswagen or Porsche that ran without complaint all summer turn over slowly or light up the tire pressure warning.

Cold works on the whole car at once, and the trouble usually starts with whatever part was already tired. Below is how that shows up, system by system, and what we check at Shawn Leonard’s shop on Eastland Drive.

Cover image: AI-generated editorial illustration, not a photograph of Stuttgart Motors or a customer vehicle.

The slow crank and the battery behind it

The chemistry inside a battery slows in the cold just as thicker oil makes the engine harder to turn. A battery that seemed fine in the heat can start to struggle.

Heated seats, mirrors and the rear window add to the electrical load in winter, so a string of short trips around Hamburg or Chevy Chase may not put back what the cold starts took out. We test the battery and the charging system together, including AGM batteries.

If the battery needs replacing, ask whether the new one is the same type the car was built with, and whether it will be registered to the car. A BMW, Audi or Volkswagen that registers its battery sets its charging to suit the battery on record.

Cold start faults that clear once the engine warms

A cold start asks the battery, starter, fuel system and ignition to work before anything is warm. A coil, sensor or connection that is starting to fail can get through the fall and then trip up on a frosty morning.

You might get a long crank, rough running until the engine warms, or a warning light that only shows on cold mornings. By the time the car reaches us on Eastland Drive, a fault like that can be gone.

The engine computer stores a snapshot of the conditions when a fault sets, engine temperature included. What you saw fills in what the snapshot misses, so tell us how it started on the coldest morning yet, which light came on and whether it sat outside overnight.

A lukewarm heater and the cooling system

A cooling problem often shows up at the heater, because cabin heat comes from hot engine coolant. Low coolant or a thermostat stuck open can leave the cabin slower to warm than it was last winter.

The same coolant keeps the engine from freezing, and any plain water added over the summer weakens that protection. Each of these makers specifies its own coolant, so if yours has been topped up, ask what went in.

On these cars the expansion tank and hose connections are often plastic, which turns brittle with age, and a joint that seals when warm can seep after a cold night. Mention any sweet smell after a drive or damp spot under the front of the car. We check the freeze protection and look over the tank and hoses.

Brakes and brake fluid after a Kentucky summer

Brake fluid absorbs moisture from the air over time, and Kentucky humidity in summer can speed that along. Water in the fluid lowers its boiling point and can corrode parts inside the system, the ABS unit included.

Roads that are wet or icy give the ABS and stability control more to do, and they work through that same fluid. Old fluid rarely changes how the pedal feels, so we check its condition and when it was last changed.

On a damp morning, surface rust on the rotors can make a light scrape that fades after a few stops. A pull under braking, or a grind that stays, is worth a look before the roads turn slick.

Tires, suspension and pothole season

Air contracts as it cools, so tire pressure drops overnight in a cold snap, which is when the warning light tends to come on.

Sportier models from these makers often come on summer tires, whose rubber hardens and grips less as the temperature drops. The sidewall tells you which kind you have. All season tires usually carry an M+S mark and winter tires a mountain and snowflake symbol, and a tire with neither is most likely a summer tire.

If yours are summer tires, ask us what makes sense for the winter, since tires for performance cars are part of our work.

Rubber in the suspension stiffens in the cold too, so a worn bushing or joint that was quiet all summer can knock over bumps or creak as you turn into the driveway.

Freeze thaw weather breaks up Fayette County pavement all winter, and by pothole season in early spring a hard hit on Richmond Road or Nicholasville Road can knock the alignment out or finish off a worn joint. We have our own wheel alignment equipment on site, so if the car pulls or wears its tires unevenly, ask for an alignment check and a look at the suspension and steering.

Before the first hard freeze

A car stored until spring still drains its battery, because its modules draw a little power even when locked. We do pre storage service before it goes away and wake it up when it comes back out, and our archive has a piece on waking a stored car.

For a car that stays on the road, ask us to test the battery and the charging system when you book it in on Eastland Drive.