A car that has sat still for six months has not simply been waiting. Standing does its own damage, quietly, and most of it is not the battery — though the battery is what stops you finding out.
This comes up constantly: a second car nobody drove, a relative’s car after they stopped driving, a project that ran out of momentum, a vehicle left while somebody was abroad or in hospital. Here is what actually happens to a standing car, in roughly the order it will cause you trouble.
The battery, which you already knew
A healthy battery left disconnected for months may survive. A battery left connected in a modern car will not, because the car never fully sleeps: alarm, immobiliser, tracker, keyless entry and a dozen modules all draw a small current constantly. Six months of that flattens a good battery and finishes a tired one.
A deeply discharged battery often will not recover even with a long charge, so a jump start that works and then fails an hour later is telling you the battery is done rather than flat. Our flat battery guide covers how to tell.
The brakes, which is the one that strands you
This is the difference between a car you can jump start and drive away and a car that has to be carried. Discs rust within days of standing outside. That surface rust is normally scrubbed off in the first few braking applications. What is not normal is what happens over months: the pads can bond to the discs, and the handbrake cables and calipers can seize with the shoes held on.
If the wheels will not turn, the car cannot be driven onto a recovery bed. It has to be winched, and that changes both the equipment and the time. It is the single most useful thing you can check before anyone comes out: release the handbrake and try to push the car a few inches on level ground.
Forcing a seized handbrake by driving off can tear the shoe linings off inside the drum, which turns a service item into a strip-down.
Tyres
Tyres lose pressure by themselves at a few PSI a month, so after half a year they are likely to be seriously low regardless of any puncture. Driving on a badly underinflated tyre destroys the sidewall from the inside, and the damage is invisible until it fails.
The other issue is flat-spotting: a tyre bearing the car’s weight in one position for months can take a set, which shows up as a vibration that sometimes works itself out over a few miles and sometimes does not. And rubber ages whether or not it is used. Check the four-digit date code on the sidewall — the week and year of manufacture — because a car that has stood for two years is on tyres that are two years older too.
Fuel, fluids and the things that rot
Petrol degrades over months, particularly in a part-full tank where condensation forms. Diesel can grow a bacterial contamination in the tank in the right conditions. Neither is usually catastrophic in six months, but both are worth knowing about if the car runs badly at first.
Brake fluid absorbs moisture from the air continuously, which lowers its boiling point and corrodes from the inside. Coolant loses its anti-corrosion additives. Neither cares whether the car moved.
And rubber and rodents: perished wiper blades and hoses are common, and chewed wiring is not rare in a car parked near open ground for a long period. If it has been outside under trees, look before you turn the key.
The question worth answering before you call anyone. Does it roll? If the wheels turn freely, this is probably a jump start and a slow drive to a garage. If they do not, it is a winch and a flatbed, and knowing which means we arrive with the right vehicle. Tell us how long it has stood and whether it moves when you call DK’s Recovery on +44 7867 860723.
If it will not roll, it has to be winched, and that means finding the car’s recovery point. Our guide to where your car’s towing eye and recovery points are explains where to look and why the wrong point does damage.
The paperwork stopped too
Easy to forget while you are thinking about the mechanical side, and the one that gets people fined.
Tax. If it lapsed and the car has been on a public road, it may already have attracted attention. If it was on a driveway with a SORN, that is fine — but the SORN does not let you drive it, and you cannot tax it without insurance and MOT in place.
MOT. Almost certainly expired. You can drive to a pre-booked test with no MOT, but you still need tax and insurance to do it, and the car still has to be roadworthy. If the brakes are seized, it is not.
Insurance. Check it is actually live rather than assuming, particularly if it lapsed while the car was declared off road.
Where all three have expired, moving the car on a truck is the straightforward answer. Our guide to transporting a car with no MOT explains it.
A sensible order to do it in
Look underneath for leaks and look under the bonnet for nests before anything. Check whether it rolls. Pump the tyres up and look at the date codes. Sort insurance and book an MOT before you plan any journey. Get the battery on a proper charger rather than jump starting and hoping. Then, when it starts, let it run and check the brakes work at walking pace before you go anywhere near a road.
If any of that stalls — and the brakes are the usual place — it is a recovery to a garage rather than a drive, and that is a cheaper outcome than finding out on the first hill.
A car that has not moved for a long time can also attract the council’s attention. Our guide to abandoned vehicle notices explains what that notice means and how long you have to respond.
Frequently asked questions
My car has stood for six months. Will it just start?
Probably not, and the battery is the least of it. Modern cars draw current constantly for the alarm, immobiliser and other modules, so a battery left connected for months is usually flat and often finished. The bigger issue is whether the brakes have seized while it sat.
How do I know if the brakes have seized?
Release the handbrake and try to push the car a few inches on level ground. If the wheels will not turn, the pads have likely bonded to the discs or the handbrake has seized on. That matters because a car that will not roll has to be winched onto a bed rather than driven on.
Can I just drive off and free the handbrake?
It is a bad idea. Forcing a seized handbrake can tear the shoe linings off inside the drum, which turns a service item into a strip-down. If it will not release, have it looked at rather than forced.
What about the tyres after standing?
Expect them to be seriously low, because tyres lose a few PSI a month regardless of punctures. They may also have flat-spotted from bearing the weight in one position. Check the four-digit date code on the sidewall too, because rubber ages whether or not the car is used.
Is the fuel still any good?
Petrol degrades over months, especially in a part-full tank where condensation forms, and diesel can grow bacterial contamination. Six months is usually survivable but it explains a car that runs badly at first.
Can I drive it to an MOT without tax?
No. You can drive to a pre-booked MOT test without a valid MOT certificate, but you still need tax and insurance in place, and the car must be roadworthy. If the brakes are seized it is not roadworthy, and it should be carried rather than driven.
