We own three A-Series and I do the maintenance and servicing on all of them. I believe routine servicing is essential and this series of articles is about how to carry out the various regular jobs that are well within the abilities of the enthusiastic amateur mechanic. I personally find this aspect of classic ownership as enjoyable as driving the cars themselves. It can also save you a fortune in garage bills. I stress however that everything that follows is just my way of going about things, my opinions and based on my own experiences of (successfully, I think) running a 1985, 176,000-mile 2cv as everyday transport. The club’s own forum has a wonderful technical section, and I urge anybody who is planning on doing anything to their car for the first time to have a read through the entries and see what pitfalls are awaiting them. A workshop manual, Haynes, or something similar, is essential too.
In an A-Series engine the spark plugs have a harder life than in most old cars. Not only do they spark every revolution of the engine (like in a 2-stroke) but, as there are only two of them, they have to fire the mixture twice as often as their 4-cylinder counterparts. As a result, after 6,000 miles they have done the equivalent work of ones that have covered 24,000 in a ‘normal’ engine. So even if your engine is running beautifully and the plugs look like the ‘normal’ picture in your Haynes manual, I think it wise to replace them at the 6,000-mile service.
How often they need changing, rather than just cleaning and re-gapping, depends on how the car is driven and how healthy the motor is. I find a quick clean with a brass brush and resetting the gap to 0.6mm at the 3,000-mile oil change usually suits our cars, but if they are black and oily or have a glazed appearance or significantly different looking from each other, they get replaced. They are not expensive and when they are getting to the end of their useful life the car starts getting very difficult to start from cold.
Along with a spare wheel, jack and wheel chock I would say every A-Series owner should carry a new pair of plugs, already correctly gapped, and a suitable spanner to fit them with. Or belong to a breakdown service…
During servicing, I remove the plugs for inspection or replacement after checking and adjusting the valve clearances, simply because I don’t want to risk dislodging any particles of carbon when unscrewing the plug and having them jamming under a valve and giving a false measurement. They are also easier to handle when cold and it is less likely for a threaded insert or Helicoil to come out, attached to the plug - which sometimes happens when they are hot.
Provided you have a spark plug spanner with a universal joint, removal is possible with the wings in place but, as always, is much easier with them off. First pull the ignition lead off by grasping the thick bit that fits over the plug, not by the lead itself. Slide your spark plug spanner over the exposed end of the spark plug and twist it until it engages in the nut and undo it anticlockwise. Remember this is a steel component screwed into a softer aluminium thread, it is not uncommon for this thread to fail, so check the old spark plug for any traces of metal in the threads.
Measure the gap of the new plug with a metric thickness/feeler gauge; and adjust by bending the outer electrode, if necessary, to 0.6mm, then apply a smear of copper grease to the threaded part and carefully screw it back in by hand, taking great care not to cross the threads. Only apply the tool when you are sure it is screwing in properly, it should turn quite easily with no tight points. If you have a torque wrench, tighten the plug to 18ft/lbs, otherwise about a quarter turn more than finger tight. They need to be tight enough to stop them from working loose and to crush the sealing washer, but not so tight that you strip the threads in the cylinder head.
If the unthinkable happens, all is not lost; my local motorbike shop will fit a Time-Sert insert (like a Helicoil, only better) into the plug hole. He’ll even do it with the cylinder head in place - at my own risk of course. It only takes 10 minutes to do. Check out your nearest one, mine charges £20, which is less than half what the town’s Citroen garage does.
Finally inspect the condition of the high tension leads that join the plugs to the ignition coil, they should be clean, undamaged and flexible and the caps that fit over the spark plugs and the terminals on the coil should have good tight connections. There are over 20,000 volts running through these cables and connections when the engine is running, if those volts can find a way of escaping and earthing themselves before they get to the spark plugs they will, and you will at best get a very weak spark, and the car will misfire and run like a pig.
Replace them if they appear dodgy with proper Bougicord items rather than with any of the cheap and nasty after-market ones. The difference in price is well worth it for their superior performance. The original (black) coil is rather sensitive to the resistance of the leads and the big caps at the spark plug end help stop some of the cooling air from escaping before it gets to the heat exchangers and then to the heater. In this weather every little helps. Last month I was explaining how to remove the front wings from a 2cv. Colin Sherriff contacted me and said that if you jack up the front of the car first, it gives you more clearance to get the wing out under the headlamp and less likely to damage the paint. Thanks Colin, a Top Tip, I’ll try that next time!
Old Goat, A.K.A. Simon Mackett