- How to: Changing spark plugs
First time servicing a Petrol (1.4 mk3 clio) and I’m going to change the spark plugs.
I have a STW approved Halfords 170 piece professional socket set which has a large section of what I think are spark plug sockets, so I have the tools.
Anything I need to be particularly aware of (cost of plugs btw?), have only ever serviced diesels so slightly wary that I’ll bugger something up.Posted 4 years agojefflSubscriber
Unscrewing plugs is easy. Need to ensure you don’t cross thread the new one’s when screwing them in. Some people use a length of rubber hose, others use their fingers. I think you may be able to use the spark plug socket as it has a rubber inside to grip the end of the ply loosely.Posted 4 years agoscaledSubscriber
I managed to do it in the dark, i’m a complete imbecile with anything mechanical.
Plugs are relatively cheap, if it’s a mk3 the HT leads should be alright for another while, but they’re an easy change as well when you get round to doing it.
Just make sure you take note of which leads go to which cylinder when you take them off 😀Posted 4 years ago
I’m hoping they will be pre-gapped (is that a thing?).
I don’t recall any rubber in the socket set – although I haven’t looked closely tbh.
This engine has coil packs – do I need to change HT leads and coil packs? I mgith as well go the full hog.
Engine is idling a bit rough, fuel economy has dropped and there isn’t a lot of power – hoping this will fix that.Posted 4 years agofinishthatSubscriber
Take care with coil packs and how they are connected to plugs – easy to damage on some cars – plugs are pre-gapped but if dropped or knocked can be wrong so you should check -very important to start new plug in thread by hand and to be sure it is not cross threaded – ie do it up by hand until it seats on the special crush washer – then you only do them up 3/4 turn max – there are directions on the plug boxes usually . Basically take your time – and if you have any history of ham fisted bodgery/breakage get somebody who has done it before to help.Posted 4 years ago
Do not buy the cheapest plugs you can get on auction sites as they could well be fakes – NGK website has details of fakes.
Depending on how the coil pack/s are setup you may have no wires just a pack on each plug or a pack and wire to plug .
Rough idle and low power could be something else – but with most modern cars the plugs get left in almost forever so unless you know they have been changed its worth doing.bj116Member
Coil packs may do away with HT leads as they usually (there’s bound to be an exception) mount straight on the top of the plugs. A duff coil pack made my Mrs Peugeot run rough. After first trying new plugs, she changed it for not too many pounds and that sorted it right out.
*Tip from Motorbike plug changing (a bi-annual event!)* I stuff the hoover pipe down over the plug before removal, to suck out all the stones/leaves/dead flies that would otherwise end up in the cylinders! 😉Posted 4 years agobutcherMember
Easiest job you can do. I think the proper plug sockets come with a rubber insert (presumably to grip the plug and lift it out?) As said, just tighten by hand. Do one at a time. Should take 5 minutes. Depending on the car, the biggest problem you might have, is getting to them. Obviously try not to drop anything into your engine while they’re out!
Plugs are dead cheap, unless you buy the premium stuff.
Idling a bit rough could be many things. But no harm in swapping out the cheapy serviceable parts first.Posted 4 years agowobbliscottMember
Just don’t over tighten the plug in the head – the threads can easily strip the threads in the head. Just give them a good nip and that’s all they need. Times i’ve not gapped plugs i’ve had no problems at all with the running of the car. If elements of your ignition system are marginal then you might get problems. No harm, it will expose other elements of your ignition system that might need changing.Posted 4 years agotronMember
Buy NGK plugs. They’re the best make you can get. They will be pre gapped and come with cardboard tubes on the end to stop them getting knocked. In theory you could check but in practice…
Coil packs generally last years and mount straight onto the plug. Normally secured by a small bolt and then just pull off. The top of the plug is ribbed so the coils can take a bit of pulling off.
The trickiest bit may be removing the old plugs if they’ve been in there for 60k. Some cars (ie Mk1 Ka) are buggers for seizing in plugs. Have a Google and see if yours is. If it is, spray plus gas down the plug holes and let it sit for a while. And take care undoing them!Posted 4 years ago
It’ll be proper sparks from a proper autofactors – brother used to use ngk in the tweaked metro turbo & rs2000 so that’s a no brainer.
I’m quite good at finger tight and 1/8th – stator plates for 0.005″ tubing helps.
Slightly worried about removing – will plus gas them a shed load and see what happens – car is 178k km, was serviced but the coil pack jumped out (spark plug really) just after, service garage took it back but I’m pretty sure they were bodged fixed as everything else they did was.Posted 4 years ago
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