38k on the clock, T-reg 1.8 Vectra 16v. Goes like the proverbial (well, for a 1.8l repmobile, it does), but has developed an occasional misfire - not really noticable above 40mph, but below that, noticeable (when occuring, which is not all the time) when doing any constant speed in any gear.
Instinct was to give it some new plugs & leads & rotor arm... until I saw the 6-point bolts holding the top onto the engine... and realisation dawned that rotor arms went out with the dinosaurs. Engine cover put it well beyond the realms of a kerbside job with a small handful of sockets.
Anybody have any other ideas?
Edited by Dynamic Dave on 25/09/2008 at 13:50
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Mapmaker,
I'm no expert in this but I had a similar problem with my Citroen Xantia not long before I sold it.
The misfire was intermittant. Occasionally it would lose power whilst accelerating or ticking over. When the problem became more frequent I popped into a local specialist who said 'Coil Pack'.
The coil pack essentially does the same job as the distributor and the coil used to. It has a Low Tension current fed to it and releases a High Tension current to each spark plug when the engine needs it. Yours probably sits above the spark plugs and plugs straight in to them.
My 2.0L xantia employed 4 separate coils, but some cars just use one for all 4 plugs. In my case it was easy to diagnose because I just removed each coil in turn to see if it made any difference to the running. However, with a combined pack it may be more difficult. I don't know whether yours is a combind pack or separate set of 4. As a good first stab though you could remove the pack and the plugs to check them for anything obvious.
If you can get hold of another coil pack from a breaker's yard or similar for a good price, it may be worth trying it.
Otherwise you're probably better off taking the car for a diagnostic session.
Hugo
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It *could* be the coil pack on its way out. Not uncommon.
Or you might be lucky and it might just need some new plugs and leads.
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Replace the spark plugs first(make sure you use the twin electrode type) But chances are the coil pack is faulty (v.common fault & v. expensive about£150 )There are no HT leads on this model.
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Thank you all.
(No wonder I couldn't see any HT leads... but then I couldn't see any spark plugs either!)
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My vote also goes to a coil pack being duff.
Failure of coil packs and idle speed controllers are the two most common problems that friends and colleagues who have driven four cylinder petrol Vectras have experienced.
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Mapmaker,
I found this on ebay the other day for someone else. The coil packs this guy is selling seem to be cheaper than from Vauxhall.
tinyurl.com/5dbtc
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Before you start spending loads of money on the problem. Check the pipe from the air filter box to the induction manifold (Big Thing) check carefully underneath for any splits in it. According to our Vauxhall guru this is a common fault and causes misfire.
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Agree 100% with Pugugly. Had the exact same problem with 1.4 16V Astra and after a week found that the pipe from air fiter box to induction manifold was split underneath. Replaced and problem solved.
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Just found it... thanks for that link, DD. And PU/aeb for the air pipe suggestion. I'll have a look at it when next I see the car. The excellent man at the garage apparently said he was very reluctant to change the coil pack as it could be lots of things, and suggested waiting & seeing what happens.
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Well, 14k miles and 18 months later, it still does it.
The garage said (18 months ago) that if it was the coil pack it would get worse & die. It hasn't.
The car is just not happy to drive really.
I even put a couple of tanks of 98 fuel through... no difference.
As soon as you get the engine turning at 2000 rpm, there's no problem... which does suggest an electrical fault.
Any ideas? Thanks.
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I should add that it has recently (again) been hooked up to a fault indicator to no avail.
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Purely as a diagnostic step, you might consider temporarily blanking the EGR.
If you find an improvement, then you might consider replacing the EGR valve.
The reason I suggest it is the intermittent nature of your fault. HT faults like the coil pack would be more consistent, or perhaps only play up in damp weather.
Number_Cruncher
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Just been through the same situation with a misfire that was mainly evident on acceleration in the lower half of the rev range. My brother insisted it was plug leads but I couldn't see it. However I eventually took his advice on board and changed them. Problem solved! Dead easy to do as well, just the two screws on the black part of the cam cover to undo and the whole lot are exposed. Change them one at a time to avoid misconnection. I paid around £15 at a local motor factors for a set made by Delco Remy which appear to be identical to the originals. You may find they're part submerged in oil that has leked from the cam cover. Just roll up a kitchen towel and mop it up, esp. if you plan to change the plugs as well.
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It's not intermittent. It's there when the engine is not under a decent level of load. So when there's just a gentle squeeze on the accelerator pedal. So cruising at 30mph in town is slightly tedious in any gear - 2nd, 3rd or 4th.
I think it is worse in cold and damp weather although I've never quite convinced myself of that. Sometimes the car will idle at 500-600rpm instead of its more normal 850 - that's poor idling.
I would add that the plugs were changed at 38k when the problem was first noticed.
How would I blank the EGR?
Archie... The car doesn't have plug leads, it has a coil pack. I might have misunderstood you?
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>I think it is worse in cold and damp weather although...
It certainly doesn't go away in the summer, nor when the car has driven 500 miles non-stop which I would have expected would have dried it all out - although it obviously wouldn't solve the traditional problems like corroded rotor arms that I'm more familiar with.
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Similar thing happened with my Dad's 1.6 Astra. No ecu warning lights, and nothing showed up when Tech2 diagnostics was hooked up to the car either. Eventually the ecu light came on and the fault was traced to a faulty coil pack and lambda sensor.
The misfire was there for nearly a year before the car's ecu finally flagged up a fault.
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>>How would I blank the EGR?
I've just re-read the thread, and I'm not sure that it is the EGR - sorry to be vague! At light/mid load is where the EGR valve should be open - so it being stuck open might not be a big problem under these conditions. Unless it's stuck wide open, but then you would expect to see idling trouble too. So, I don't hold out much hope that it is the EGR in your case.
Anyway if you wanted to blank the EGR, to rule it out of any further diagnosis, I think you can now get hold of a blanking gasket from Vauxhall which fits between the EGR valve and the manifold. Failing that, you might have to fashion one yourself - the one currently performing erm.. cough cough.. diagnostic duty on our Astra is little more than a piece of bake bean tin.
One other thing springs to mind, which is that the earth wire from the coil pack can sometimes be troublesome, and in many cases, running another earth directly to the battery effects a repair.
Number_Cruncher
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Mapmaker,
Just trawling the web and noticed your cars fault sounds similar to my own. My 1.8 16v petrol 99 Vectra started struttering if I gave it too much gas a while back. A mechanic took a look and straight away saw the reason for it was that a coil spring had actually broken off conpletely and was loose within the pack. A quick patch up with a bit of gaffer tape seemed to solve the problem but recently the same thing has cropped up again. Decided to bite the bullet and actually put hand in pocket and went to a breakers and got a replacement coil pack - the cassette type - for 35 quid. Problem solved and the cars purring well
Cheers
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Well, four years and 32k further on, I have a diagnosis.
Ihad the cambelt changed as the tensioners were noisy, and it was changed by a Vauxhall enthusiast (sic!). He raved about the engine being bullet proof (despite cambelt tensioners that need changing every 40k and all the other notorious faults mentioned on this thread. Whatever...
Apparently the hydraulic tappets soot up - as does everything on this Ecotec engine as posts above relate - so oil doesn't get through the little holes, so there is no compression.
One day this will apparently refuse to start... until then, sixteen of them at £25.38 each looks somewhat expensive...
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