Just had the plugs changed on my Panda, for a while now I had suspect it wasn't running right so took it to a local indie. He checked it with his expensive diagnostic equipment and no faults were showing. Lamda sensor values were all correct etc. He suspect the plugs should be changed.
I also had problems with damp, if I hadn't used it for a few days in damp weather the engine would run on three cylinders for the first few seconds so he put WD40 on the electrical connections including the plugs.
He changed the plugs and found one of them was burning out, it was all black near electrode. Since the car now has new plugs acceleration is noticeably faster and it sounds smoother at idle.
My car has done just 15,400 miles I thought they were supposed to last longer these days? Although the car is almost four years old so maybe it is the age that has killed them? Either way I will hopefully get the £30 back in better MPG :).
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My X type -IIRC schedule says change plugs at 70K /7 years.
It has done 25K and coming up to 7 years.
I wonder what a main dealer will be recommended this year ?
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15,000 miles does seem low to have the plugs changed then, he showed me the electrode on one of them and it was black, the others all looked in very good condition. I just hope there is nothing more serious which has caused one of the plugs to burn out prematurely, could just be a manufacturing defect I guess.
That said my engine has been around since the 1980s virtually unchanged, although the electronic ignition system I guess should be modern.
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Possibly a dud plug/plug lead, causing fuel residue build up -not hot enough to burn off? How was the ceramic colour on the plugs? I seem to remember a plug chopping session on my Norton:)
Last edited by: NIL on Thu 30 Jan 14 at 18:45
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I would say it was sooty coloured about 1-2cm onto the ceramic itself. I didn't pay that much attention.
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>> He checked it with his expensive diagnostic equipment and no faults were showing.
If you're saying he used something expensive to read fault codes then you could have done that yourself for a few quid. Get a Bluetooth OBD II reader and some free software for your phone. Got one recently to check the fault light on the Seicento was - pin pointed a temperature sensor. Got the sensor and fitted it. Then used the OBDII reader/scanner to reset the error.
I got the reader off Amazon - about £7 including postage.
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4 years isn't bad for what is (let's face it) a cheap car.
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Seems to indicate a duff plug. However a more knowledgable chap may come along in due course:)
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As deposit formation is a highly temperature sensitive process, is it possible that Rattle's car simply hasn't been used enough?, the plugs never really getting hot enough to work properly?
I don't think the plugs are at fault ....
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Only one seems to be blackened. Why one and not four?
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Seems to indicate a duff plug. However a more knowledgable chap may come along in due course:)
Lack of spark, or an over rich mixture. Spark plug being faulty is the most likely, although I once donated a lead to a BBC technical vehicle I had for a week. Quite surprising how bad an eight cylinder engine was only running on seven.
Last edited by: Slidingpillar on Thu 30 Jan 14 at 19:34
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I agree with Sp about it possibly being something to do with the spark supply - plug not firing - unburnt fuel turning the electrode black.
Does that engine have coil packs?
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Thought plugs were pretty long life now - 60K+
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>> Possibly a dud plug/plug lead,
Do cars still have plug leads? I thought they all had coil packs connected directly to the plugs nowadays.
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>> >> Possibly a dud plug/plug lead,
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>> Do cars still have plug leads? I thought they all had coil packs connected directly
>> to the plugs nowadays.
I have both. I have a coil pack on top of one plug, with a lead going to the next plug. So two coil packs and two leads.
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>My X type -IIRC schedule says change plugs at 70K /7 years.
Same as my XJ.
Service book for my Z28 says that plugs should be changed at 100K - no time limit. According to other owners, access to 7 & 8 (the rearmost two) is almost impossible unless you have very small hands or drop the engine a couple of inches so I hope they do last that long.
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Very likely what N_C says - the car does under 4000 miles/yr, presumably sitting idling in traffic and pootling on a cold engine.
The fact one plug is mouldier than the rest is likely because of the different rate that different parts of the engine warm up, and the minor discrepancy in richness of mixture that are between cylinders.
IIRC on 4 cylinder Subaru engines the rearmost passenger-side cylinder tends to run leaner than the other 3 for such reasons which can occasionally lead to issues.
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Leaner possibly, but emissions controls on a modern engine would, I'd guess, mean that major variations in fuel/air ratio were impossible. Unless the cylinder was not firing/misfiring grossly.
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>>but emissions controls on a modern engine would, I'd guess
One aspect of lambda closed loop mixture control is that the sensor (in most engines) samples the exhaust gas from all cylinders in that bank of cylinders. This means that it's possible, if not probable that some cylinders can run rich, others weak, but yet overall the emissions average out acceptaby.
There are some numerical methods / algorithms which can be included in the engine management unit to compensate for the varying delay between the combustion process in a cylinder and that gas reaching the sensor, but these methods rely on some fairly basic assumptions, and the flow in manifolds is anything but simple.
Similar arguments and concerns may be raised about mass airflow sensors - it's not a trivial task to link the signal from the mass air flow sensor at any instant with the mass of air being trapped in any particular cylinder. Again, the varying delay time, the varying throttle opening, and the complicated flow regime in the manifold make even quite sophisitacated algorithms in the ECU little better than a rough guess.
As Lygonos has also mentioned each cylinder also runs at a different temperature - the ones furthest from the water pump tending to run hotter.
Of course, it could easily be a duff plug, but, the type of use the car has been getting isn't helping matters.
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>>Service book for my Z28 says that plugs should be changed at 100K
Might be because of US legislation about no significant service parts needing changed until 100k miles (although sparkplugs are usually thought of as consumables) - timing belts in the States need to last at least 100k miles, hence the number of identical cars which have 60k mile belt changes in Europe, but 105k miles in the US (same belts).
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>Might be because of US legislation about no significant service parts needing changed until 100k miles..
Probably correct Lygonos.
I know that emission control components are covered for 100K so cats and the like are covered but I didn't know that it applied to plugs and belts.
Dropping the warranty to 60K in Europe must be a nice little earner.
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>> >My X type -IIRC schedule says change plugs at 70K /7 years.
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>> Same as my XJ.
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>> Service book for my Z28 says that plugs should be changed at 100K - no
>> time limit. According to other owners, access to 7 & 8 (the rearmost two) is
>> almost impossible unless you have very small hands or drop the engine a couple of
>> inches so I hope they do last that long.
some kind of tool will be available
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>some kind of tool will be available
You need small hands, a lift, ramp or pit (they're only accessible from underneath) and a multi-jointed wrench, and if they are tight you just can't get enough force on them.
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>>some kind of tool will be available
>>
On the X type, the service with plug change is much more expensive. IIRC a manifold etc has to be removed to get at the rear plugs of the cross mounted V6.
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>> I also had problems with damp, if I hadn't used it for a few days
>> in damp weather the engine would run on three cylinders for the first few seconds
The last time I had those symptoms it was the head gasket starting to go allowing a small amount of coolant to trickle into one cylinder when it was standing overnight which would stop the plug firing on that cylinder for a few seconds till the heat dried it out.
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Plug change interval on my Vectra is 8 years / 80,000 miles (whichever comes sooner)
Changed at last service (87,000 miles) with hardly any wear to them.
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Rattle. Here is a set of (mostly) dodgy plugs plus commentary on causes.
: www.gnttype.org/techarea/engine/plugs.html
Recognise any?
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>> Use NGK plugs....:-) :-)
>>
Use Denso plugs
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Ask your indie to remove the engine, it'll save you a lot of fuel.
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R&S
This can give you some sleepless nights www.fiatforum.com/panda/340730-1-2-8v-misfiring.html
or alternatively it will de-stress you from thinking about lead poisoning www.des.umd.edu/os/rest/lead.html
Dont worry if you have all the symptoms - most of us here probably exhibit them!
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>> www.fiatforum.com/panda/340730-1-2-8v-misfiring.html
There's some serious twaddle in that thread about how to tension head bolts.
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It is of course a well known fact in motoring circles that Pandas begin to deteriorate rapidly from their fourth year, rapidly turning from an economical runabout into an all consuming money pit. No amount of care and servicing can stop this inevitable progress.
Fortunately the onset of this process is always betrayed by the same symptom, namely the failure of a single spark plug. Be afraid - very afraid.
Heed the signs and start searching for a new motor now. :-)
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CGN ..and I thought I was a little cruel :)
Last edited by: sherlock47 on Fri 31 Jan 14 at 10:07
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"one of them was burning out, it was all black near electrode"
That's a bit contradictory, isn't it? Far more likely to be a lead or even just a poor connection at the plug top, now rectified by the change of plugs!
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Do 'diagnosticians' use an oscilloscope these days I wonder? I would have pounced on the fault within seconds via my Crypton analyser back in the olde days.
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Plugs on the Octy are are a 60k service item. Good job too, as they are platinum tipped, and hence quite pricey.
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Plugs on the Note are platipus as well. I have a set waiting but when I saw you can only get no. 4 out without removing a manifold....I deferred the job. I just check No. 4 now and again.
Must do an oil change soon...got the filter and oil but there's a Singer Chamois coupe sat in the drive on SORN while my neighbour has his roof replaced.
HO
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>> I just check No. 4 now and again.
I worry about replacing removed plugs. How can you be sure the (previously) compressible washer will be doing its job?
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Just got back in I really should have been an investment (?)anker. I did about 30 miles in today and 40 yesterday, it is running a lot better and idles better, so I am just putting down to a duff plug. Obviously if it fouls up again there is a problem. Somebody mentioned head gasket but there is no symptoms whats so ever of that, no smoke, no loss of coolant, and the oil cap is perfectly clean.
I think it is mainly the 1.2 FIRE that suffers from HG problems, the 1.1 doesn't seem to suffer in the Panda, although my dads old Punto had th same engine and I suspect the HG was failing on that, but be wrote it off before it became an issue (lets just say the police took pitty on him and he got away with quite a serious accident).
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Could you not whip that particular plug out yourself now and again, to check it?
The Fire engine was about years ago when I was in the mobile tuning game and ISTR it was easy to work on.
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My "Fire" engined Panda went over 150,000 miles and I can only remember taking a plug out once in that time,looking at it and putting it back in-mind you,my shortest journey in it was 20 miles with negligible traffic.I only got rid of the car when the non-galvanized parts of the bodywork collapsed-mechanically,the car was still good.
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Plugs in my Subaru are NGK Iridium, £10 each on eBay, but they were changed at 60,000m, before I got it
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How long do spark plugs really last? - henry k
