QuestionQUESTION: hello there i have a 2004 astra mk5 1.6 twinport it as 113,000 miles and the exhaust/cat converter sign as come on its also very judery i have taken it to a diagnostic and they said it was cylinder q missfire need to look for part but dont know what i am looking for could you explain it to me any more please.
ANSWER: Whichever cylinder number it is, the single cylinder misfire points to something wrong with only that cylinder, it's either a sparkplug, a sparkplug lead (HT Lead) of faulty injector
With this juddering... sounds like one cylinder is totally out of action - I suggest replacing the sparkplugs and HT leads as a matter of course, since the warning light comes on this means fuel is going down the exhaust and not being burned (usually), so you can probably rule out a faulty injector. (but it is still possible, only injectors cost around £100 and a set of plugs and leads are around £40/£50 or less if you shop around well, and are due for replacement anyway as a service item being 6+ years old.
Either a dirty sparkplug or a faulty/loose sparkplug lead is the most likely cause-> parts shop will supply you with a set of both, shop around for the best price, prices vary a lot.
a garage or any mechanically minded person can replace the plugs and leads for you, it's a ten minute job and very easy.
If you need any more advice don't hesitate to ask.
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QUESTION: Thank you for answering my question so fast the diagnostic machine report as p0301 cylinder Q missfire can you shed any light on that for me please.
AnswerThats cylinder number 1 misfire.
Lack of spark/fuel or compression to plug no1.
- Just realised this engine has coil packs, EG a separate coil for each plug. instead of 1 coil and set of HT leads...
Sorry!
This error code and the symptoms both point to a faulty "coil pack" then.
~(same fault, just parts are set out differently)~
(a coil pack is just the same as a "coil and leads" but it's more modern, EG it is kept in a hotter place, fails more frequently is harder to diagnose/test and is more expensive to replace.....)
The coil pack is £126 from vauxhall, but you could find it cheaper on ebay or from a motor factors or independent parts store, Halfords would be nearly the the same as dealer price.
Coil pack is a common fault on these, check it's wiring is secure before replacing it, just in case it's a loose wire. 1 hours labour / 10 minute job to swap coil packs and then the spark-plugs should be cleaned or you will still have a misfire because plug no1 will be fouled with fuel residue.
Best to buy the part yourself and get an independent garage (or parts shop if you have a good independent parts shop near you) to fit the coil pack, maybe get the job done for £80-£150 that way. Or at the dealers would come to around £300 skies the limit really.
If it were my car I'd buy the coil pack from "Carlines" or some other independent parts shop (likey £65 - £90) and ask if they could fit it for you, they may charge but not a lot, it's really an easy job, the parts shop will usually have a parts fitter on hand and be more than willing to do little jobs like this. Phone up and ask a few local parts shops if they will supply and fit the coilpack first to avoid disappointment)
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It's a case of opening the bonnet, taking off a plastic cover with 6 or so bolts, undoing 6/8 bolts on the coilpack and swapping it, then putting the bolts and covers back. Done in less time than it takes to drink a cup of tea...
And if you cant find a parts shop who will fit it (cheaper) the garage you got the scan done at will likely fit the coilpack for £20/£30 or so. Best to buy the part yourself at an independent - phone a good few shops to find the best price, it really pays to shop around for these things - and once you have the part get it fitted there and then if possible or phone a few garages for a price, £20 should be your target price for getting it fitted :-) and try and get the coilpack itself for under £70, hold out for £55 if you have the patience, I know they sometimes go that cheap.
There are some coilpacks on ebay starting at £20, make sure you get the right one.
