Most of the things that leave people at the roadside, or that turn into an MOT failure, are visible from the driveway with no tools and no experience. The car used to film this was an old Clio, and in the course of five simple checks it turned up an empty washer bottle, coolant close to minimum and a blown sidelight bulb. None of those needed a garage. All of them needed somebody to look.
This is the routine to run once a week if you do big miles, or once a month for ordinary use, and always before a long journey. It takes about fifteen minutes the first time and rather less once you know where everything lives on your car.
Nothing here requires you to get under the vehicle or remove anything. If you have never opened your bonnet, this is a good place to start.
Do these with the engine cold
Oil, coolant and everything else read correctly and safely on a cold engine standing on level ground. A hot cooling system is pressurised and taking the cap off can scald you badly, and a hot engine gives a false low oil reading because the oil has not drained back to the sump. First thing in the morning, before the car has moved, is ideal.
What You Need
The UK Car Owner's Essential Guide
- Every dashboard warning light explained
- Fluid, tyre and service checks you can do yourself
- How to avoid getting stung at a garage
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The Five Checks
Washers and wipers
Start the car, run the washers and watch what happens. On the Clio nothing came out at all, because the bottle was empty. Find the bonnet release, usually in a footwell, then the safety catch under the bonnet edge, and prop the bonnet on its stay if it has no gas struts. The washer bottle cap carries a picture of a windscreen with water spraying. Top it up, ideally with proper screen wash rather than plain water, since screen wash resists freezing and cuts road film. Then check the blades: run a finger down the rubber feeling for splits or a strip that is coming away, and watch whether they clear the screen or leave smears.
Engine oil
While the bonnet is up, find the dipstick, pull it out, wipe it clean on a rag, push it fully home and pull it out again. That second reading is the true one. There will be minimum and maximum marks, and you want the level comfortably between them. If it is at or below minimum, top up through the oil filler cap with the correct grade for your engine, a little at a time, rechecking as you go. Never fill above maximum, because too much oil is its own problem. If the level keeps dropping between checks, that is a fault to investigate rather than a habit to maintain.
Coolant
The coolant expansion bottle is translucent with minimum and maximum marks on the side, so on most cars you can read the level without opening anything at all. It should sit near maximum when cold. Only remove the cap on a cold engine, and top up with the correct coolant type for your car rather than plain water where you can, since the antifreeze is also the corrosion inhibitor. As with oil, coolant that needs topping up regularly is telling you about a leak somewhere.
Tyres
Take a torch to all four. Look along the sidewalls for cuts, bulges or cracking, since a bulge means structural damage and needs the tyre replaced regardless of tread. Look across the whole width of the tread, including the inner edge that you cannot see from standing, because uneven wear there points at alignment or worn suspension. The legal minimum is 1.6mm across the central three quarters. Use a tread depth gauge, or use the outer rim of a 20p coin: insert it into a groove, and if you can still see the rim the tyre is close to or below the limit. Finally check the pressures with a gauge against the figures on the door pillar sticker, the fuel flap or the handbook.
Lights
Turn the ignition on and work round the car. Sidelights, dipped beam, main beam, indicators on both sides including the side repeaters, hazards, reversing light, rear fog light and front fogs if fitted. Do not forget the number plate lights, which fail quietly and are an MOT item. For brake lights, either use a helper or reverse towards a wall or a window and watch the reflection. On the Clio a front sidelight was out and would have been an easy failure. Bulbs are cheap and most are quick to change, and this is the single most common thing found on these checks.
Why These Five
Each of these catches a different category of problem. Washers and wipers are about being able to see, and a car that cannot clear its screen is genuinely dangerous as well as an MOT failure. Oil is about whether the engine survives, and low oil is the fastest way to turn a running car into a scrapped one.
Coolant is the same story from the other direction, since an engine that overheats can warp a head or fail a gasket in the space of one journey. Tyres are the only part of the car touching the road and carry both the legal exposure and the grip. Lights are about being seen, and they fail without any warning to the driver at all.
Between them they cover most of what leaves people stranded and a large slice of what fails MOTs. None of them needs a tool more complicated than a rag.
How Often, and When It Matters Most
Weekly is right for high mileage drivers, monthly is fine for ordinary use, and before any long journey is non negotiable regardless of when you last looked. Take the extra minute before towing, before a fully loaded holiday run, and at the start of winter.
Older cars need looking at more often than new ones, because a car that consumes a little oil or seeps a little coolant is not necessarily faulty at that age, but it does need monitoring. If you find yourself topping the same thing up on every check, that has stopped being maintenance and become a fault worth diagnosing.
Keep a note of what you top up and when. It costs nothing and it turns a vague sense that the car uses a bit of oil into a number you can act on.
What to Do With What You Find
Bulbs, screen wash and tyre pressures are all jobs for the driveway. Most bulbs are a few pounds and accessible without tools, though some modern cars bury headlight bulbs behind the wheel arch liner or require the headlight unit out, so check before assuming.
Book it in for anything structural. A bulge in a sidewall, tread below the limit, brake fluid or coolant that is visibly leaking, or an oil level that has dropped significantly between checks all need a professional look rather than a top up. The point of doing these checks is not to fix everything yourself, it is to find things while they are still small and cheap.
Common Mistakes
- Checking oil on a hot engine or a slope. Cold and level, or the reading means nothing.
- Opening a hot coolant cap. The system is pressurised and it will scald you.
- Reading the dipstick on the first pull. Wipe, reinsert fully, then read.
- Overfilling the oil. Too much causes its own damage. Top up gradually and recheck.
- Topping the same thing up every week and calling it maintenance. That is a leak.
- Only looking at the outer edge of the tyres. The inner edge wears first and is where alignment faults show.
- Forgetting the number plate lights. They fail silently and they are an MOT item.
- Using plain water in the washer bottle through winter. It freezes, and then you have no washers at all.
