Every February, the workshop fills up with cars suffering from the same two problems: pothole damage and salt corrosion. Both happen quietly, both get worse if you ignore them, and both can turn a cheap fix into an expensive repair if you leave them too long.
This is what I look for first when a car comes in for a winter health check, and how you can spot the warning signs yourself.
How Potholes Wreck Your Car
A single sharp hit with a deep pothole can do an astonishing amount of damage. We're talking split tyres, bent alloys, cracked springs, and knocked-out geometry all from one bad bang.
The damage isn't always obvious straight away. Some of it shows up weeks later as uneven tyre wear, new vibrations, or a car that just doesn't drive like it used to.
Signs of Pothole Damage
- ▸A sudden pull to the left or right after a big hit
- ▸Steering wheel no longer centred when driving straight
- ▸New vibrations through the wheel or seat at 40–70 mph
- ▸Tyre wearing more on one edge than the other
- ▸A visible bulge on the sidewall of a tyre
- ▸A hairline crack or dent on an alloy rim
- ▸Clunks from the suspension over bumps
If you spot a sidewall bulge, stop driving on that tyre. That's a blowout waiting to happen.
What to Do After a Bad Pothole Hit
- ▸Pull over safely as soon as you can and check the tyres and wheels for obvious damage
- ▸Note the location — you can report it to the council and potentially claim for repairs
- ▸Book a tracking (wheel alignment) check within a week or two
- ▸Keep an eye on tyre wear for the next few thousand miles
A fresh alignment costs far less than a premature set of tyres.
How Road Salt Attacks Your Car
Grit lorries spread rock salt mixed with brine, and that salt clings to everything it touches — exhausts, brake lines, subframes, wheel arches and any exposed metal underneath.
Salt accelerates corrosion dramatically, especially where paint or undersealing has already been chipped by stones.
The Areas I Always Check First
- ▸**Rear sills and wheel arches** — classic British rust traps
- ▸**Brake lines** — pitting here is an MOT failure and a safety issue
- ▸**Exhaust system** — holes often appear at welded joints after a salty winter
- ▸**Suspension arms and bushes** — corroded bolts turn small jobs into big ones
- ▸**Underbody subframes** — surface rust is normal, structural rust is serious
Washing the Salt Off — The Easy Win
Most salt damage is genuinely preventable with a bit of regular washing. You don't need anything fancy.
Winter wash routine:
- ▸Give the car a proper wash every 1–2 weeks once the gritters are out
- ▸Use the jet wash at a hand-car-wash to blast under the arches and sills
- ▸Pay special attention to the underside if you've done motorway miles
- ▸Don't skip this just because it'll "only get dirty again" — that's the whole point
If your car is more than five or six years old, it's also worth asking about a fresh undersealing treatment. A hundred pounds or so now can add years to the life of the bodywork.
Brake Lines — The One That Catches Most People
Corroded brake lines are the single most common MOT failure we see in February and March. They rust from the outside in, and you usually can't spot them without getting the wheels off and having a proper look.
What to look for:
- ▸Fluid dampness anywhere on the underside
- ▸Spongy brake pedal or increased stopping distances
- ▸A brake warning light (never ignore this one)
Replacing a corroded brake line is a job best done before it actually leaks. Once a pipe has burst, you're looking at reduced braking and an unsafe car.
Book a Winter Damage Check
If you've been driving through a proper UK winter, it's genuinely worth getting the car up on a ramp for a proper look. A Winter Damage Inspection takes about 30 minutes and covers:
- ▸Full underside check for corrosion and salt damage
- ▸Brake line and brake system inspection
- ▸Wheel alignment and tyre check
- ▸Suspension and steering joints
- ▸Any knocks or new noises you've noticed
You'll walk away with a clear honest report and a sensible list of what (if anything) needs sorting now, and what can safely wait until your next service.