UNDERBONNET CHECKS

1 REMOVE AIR CLEANER 1

To access most of the engine service items, and to change the air filter if needed, the box must come off. It’s held on by two rubber bushes. In our case these bushes were badly worn, allowing the whole housing to rattle. You can’t, apparently, buy them separately from the filter box. See later for how we overcame this.

4 REMOVE COIL PACK

2 REMOVE AIR CLEANER 2

With the bush bolts undone, you can lift the box off. Strictly speaking, you can do all the service stuff underneath with the box moved over and the breather and vacuum hoses still connected, but access is far easier if the box is right out of the way, and disconnecting the pipes really isn’t a big issue.

As this is a 24,000-mile service, we’ll be changing the spark plugs, and though it’s not essential, access is easier with the coil pack removed. You will, though, need to search the bottom of your toolkit for the usually-missing 10mm socket! Then move the pack over and out of the way, disconnecting the plug leads as you go.

6 FIT NEW SPARK PLUGS 1

These days, spark plugs rarely need cleaning thanks to cleaner fuels and oils, and most manufacturers instead simply recommend new ones every two or three years. These febi bilstein plugs are ready gapped and ready to fit.

3 CLEAN THROTTLE BODY

Our throttle body assembly looked a bit cruddy, so Andy sprayed specialist cleaner around, and then wiped the body clean with a suitable clean cloth. If you’re new to DIY car work or, like me, a little clumsy, it’s not a bad idea to leave the cloth inside the throttle body until you’ve finished working elsewhere, in case you inadvertently drop anything inside.

5 BLOW AWAY DIRT FROM ENGINE TOP

Next, remove any dirt or dust that’s built up around the plugs, so it can’t drop into the cylinders when the plugs are removed. The easiest way, if you’ve access to one (and have plugged the throttle body air intake as explained above) is with an airline. Alternatively, use a wire brush and/or a workshop vacuum cleaner.

7 FIT NEW SPARK PLUGS 2

Old and new spark plugs compared. This is in fact pretty-much textbook for how the electrodes should look, and these plugs would undoubtedly have been fine to refit, but the schedule says renew, so that’s what we did. Double-check the plug ends look the same before fitting, especially the threaded section length.

8 FIT NEW SPARK PLUGS 3

Fitting the new plugs. It’s sensible, again especially if you’re new to DIY or unfamiliar with these engines, to screw the plugs in by hand at first, so you can feel them going in evenly and that you aren’t cross-threading anything. Then finish off using a plug spanner. There’s actually a spark plug torque wrench setting of 25Nm or 18lbf.ft

13 CHECK/RENEW AIR FILTER 1

This is down for a three-year/36,000-mile change but given that Fiat 500s tend to be city cars, that’s very much a maximum, and we’d certainly check it – and probably renew it – every two years. To access the filter, undo these 8mm retaining bolts around the edge of the box body, and separate the two halves.

9 CHECK BRAKE FLUID LEVEL

Remaining underbonnet stuff is generally straightforward ‘look and read’ stuff, with seethrough reservoirs for most things. Brake fluid needs renewing every two years/24,000 miles. A noticeable or significant drop needs checking out but slight lowering over time is normal because, as pads wear, the caliper pistons rest further out and with more fluid behind.

11 CHECK/CHANGE COOLANT

Engine coolant needs level and strengthchecking every year, and renewing at two years/24,000 miles. Check too for signs of oil contamination; head gasket leakage/failure isn’t unknown on these cars. Use OAT (red) coolant or anti-freeze concentrate. Total system capacity is

4.85 litres, and the drain point is on lower left-hand end of the radiator.

12 REFILL ENGINE OIL

Though oil drain and oil filter are ‘underneath’ – see next section – the refill, obviously, is on top. Go steady with the 5W-40 though, as the sump holds just 2.5 litres. It’s also a fairly slow fill and the oil takes time to drain down into the engine, and of course a little bit of old oil will probably be left in the sump; keep checking the dipstick!

10 CHECK CLUTCH FLUID LEVEL

Clutch is also hydraulic, and again there’s a handy see-through reservoir. Hydraulic clutch fluid doesn’t need routine renewal as clutch operation doesn’t generate heat in the same way as braking, and fluid boiling due to moisture absorption isn’t therefore an issue.

14 CHECK/RENEW AIR FILTER 2

This will reveal the air filter – obviously only one side of it should be dirty; that shows it’s doing its job! Remove any debris from the inside of the housing, and then install the new filter, before boxing it all up again and putting the box back on the engine – not forgetting to remove that cloth from the throttle body first!

15 TOP-UP SCREENWASH

This might seem a trivial item – until you actually need it! It’s also, if you’re servicing the car in a professional capacity, the sort of thing which, if missed, might make a customer wonder what else you haven’t done. Total capacity is 2.5 litres, and a good additive stops the system from freezing and aids the cleaning function.

18 RENEW OIL FILTER 2

New oil filter about to go on. To aid sealing, smear some engine oil over the sealing rubber, and fill some of the filter with fresh oil to help the system prime on first start-up after the oil change. Hold a (gloved) finger over the hole as you take the filter under the engine – remove it just before you put the filter in position, and then take it hand-turn tight only.

16 DRAIN ENGINE OIL

This would normally be the first thing you do when the car arrives, as warm oil flows more easily. Be careful though, as it’s also very capable of causing severe burns if it contacts your skin. The drain plug is on the back of the sump and comes off with a 12mm Allen key. Unusually, Fiat recommend 6000 mile/six monthly oil changes.

19 FRONT WHEEL SPIN

With the front suspension jacked up and properly supported (but don’t forget just crack-off the wheelnuts first) you need to ‘spin, shake and rattle’ the front wheels to check for binding and wheel bearing suspension/steering wear and movement. By and large, Fiat 500s are no better or worse than anything else in this respect.

21 CHECK SUSPENSION

With the front wheels off, inspect the suspension and steering for obvious faults. Fiat 500s can suffer with rusty front suspension top mount bushes, though this is generally easier seen from on top. Coil spring corrosion was an advisory on this car’s last MOT; I suspect a tester covering his back on a car he knew was being sold!

22 CHECK BRAKES/PADS

In theory, you can check the pad thickness without disturbing the brake calipers, but it’s so easy to do a full job that there really isn’t any reason not to. All you have to do is pull out the bottom pad retaining clip, and pivot the caliper upwards. The pads can then be removed, checked, cleaned and refitted or renewed as required.

17 RENEW OIL FILTER 1

The oil filter sits underneath, at the very front of the engine, and is easy to access and remove using a proprietary filter removal tool or even, if you’re a real cheapskate, the old ‘screwdriver through the body and turn’ method! Once, oil sump rust was almost unheard of; now, it seems, it’s almost a universal weak-spot!

20 CHECK TYRES

This tyre, on the other hand, fully deserved to be MOT advised, as around 1000 miles later it was a definite failure; time for a tracking check and adjust methinks! Don’t forget too that taking the wheels off means you’ve got a perfect opportunity to check the tyre inner sidewalls for defects and damage.

23 REMOVE REAR BRAKE DRUM

According to the schedule, the rear brake service comprises checking handbrake function annually, and a three-year/36,000-mile check on shoe thickness by looking through a hole in the backplate. We, however, prefer a more thorough inspection. So remove the centre nut (32mm socket) and pull the drum off.

26 RENEW POLLEN FILTER

We actually did this as part of my Our Cars story last month, but as it’s on the service schedule we need to show it again here, for completeness. The filter lives under the fascia on the driver’s side and next to the heater blower motor. It sits sightly curved when installed, and you need to feed it in carefully.

24 INSPECT BRAKES

As you can see, the rear brakes are a straightforward two-shoe and two piston wheel-cylinder affairs, with a manual adjuster. In practice the rear brakes don’t do that much, so wear is likely to be minimal. Do, though, give the whole area a clean with brake cleaner, and ensure everything is free to move as it’s supposed to.

27 AIR CLEANER BOX FIX

This, too, we showed last month but needs to go in here as well to complete the story. As replacement fixing bushes aren’t available separately, I cut a tap washer so that it fitted around the metal centre. Then, with the bolt and metal washer tightened down, the old bush was compressed sufficiently to grip as intended.

25 CHECK BRAKE ADJUSTER

In theory, rear brake adjustment is automatic, via the handbrake operation. In practice, low wear means things often seize before they move, and manual assistance is required. This is done by refitting the drum and then flicking the adjuster through a hole in the drum until it locks. Then back off one or two clicks until its fully-free.

28 AND FINALLY...

Some rather useful servicing advice on the label under the bonnet concerning oil use. We’d never have guessed.