2006 QP. Intermittent misfire.
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Elliott653
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It's the two plugs nearest the bulkhead. They had to remove the top scuttle, windscreen wipers and other gubbins to get to them. We don't even know if it solves the problem. The poster who has his car at Shiltech has had this done and still the problem returned.
Oh well, the joys of Maserati ownership.
Elliott653
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Apparently, every four years.
Gixerboy
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Hope it fixes it for you,
Plugs are a consumable & seem to get overlooked..
The diagnostics can only detect so much, a plug misfire is one of them faults that may display as coil or emissions due to no spark being able to jump the enlarged or fouled Plug gap. Unburn fuel can then enter the cat & cause the emissions to "hunt" .
New plugs us always a good place to start on any make of car if it misfires under load.
I'm probably tempting fate, but
Plugs are a consumable & seem to get overlooked..
The diagnostics can only detect so much, a plug misfire is one of them faults that may display as coil or emissions due to no spark being able to jump the enlarged or fouled Plug gap. Unburn fuel can then enter the cat & cause the emissions to "hunt" .
New plugs us always a good place to start on any make of car if it misfires under load.
I'm probably tempting fate, but
TridentTested
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I've had this conversation with McGraths before and mentioned that some indies do a magic bit of squeezing the plug change in without removing all this clobber. I don't know how they do it, maybe they put vaseline on their arms!
McGrath's view is it can be done but the coil packs are too expensive, and too easily damaged, to risk. They prefer to follow Maserati's procedure as above.
Elliot, fingers crossed, eh?
Parisien
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Well this is were the indies superior knowledge and familiarity with the more complex breeds come in, as the car ages, different things give bother in the post 6/7/8 year period, some peculiar to certain years and models, only by building up those 20/30 years worth of knowledge can you deal with some of these issues....once a car goes beyond the above timespan, the MDs loose touch with them, what to look for, how to interpret diagnostics, what things to instinctively look out for....
Indies 6....MDs 0 , when dealing with the older Masers
P
Indies 6....MDs 0 , when dealing with the older Masers
P
Andyk
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That does seem like they have had 6 tea breaks between moving each one frank...
Elliott653
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I was there the whole time. He was working the whole time (other than lunch) , that's how long it took. I'm not concerned about the time, nor the money, to be honest. I AM concerned whether the fix has worked.
And, for that to be proven one way or the other, the car needs time & miles.
And, for that to be proven one way or the other, the car needs time & miles.
daverichardson
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Hi Gixerboy
I have been reading about misfires on QP
Mine is 2007 auto and faults were misfire on Cylinder 7 and 8
But which are they?
LHS or RHS
Near the cabin or near the front of the car
Plugs on order for delivery tomorrow and then some fun starts
I have been reading about misfires on QP
Mine is 2007 auto and faults were misfire on Cylinder 7 and 8
But which are they?
LHS or RHS
Near the cabin or near the front of the car
Plugs on order for delivery tomorrow and then some fun starts
TridentTested
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My QP wanted to join this club.
I had the same experience yesterday on a five hour run. The misfire developed about an hour into it; flashing orange engine light, slight vibration and hesitation from the engine, uneven exhaust pulses, but went away again. Towards the end of our journey, just like with Elliott's experience, it got worse and felt like at least two cylinders had gone on holiday; pulling away from roundabouts was not fun.
The car sat for a few hours, on a car ferry, then ran fine thereafter - with an "engine control system failure, go to dealer" message now flashing; which I presume will continue flashing until the error codes are cleared.
It really sounds like the same problem but while I can understand one coil-pack, or one spark-plug, failing at a random moment how do you explain two, or maybe more, going south at one time? And indeed giving trouble yesterday and then working again?
The plugs have never been changed in my ownership and my brother has a cynical theory that a previous garage might have changed the six accessible plugs only; meaning the inaccessible ones might be nine years' old now.
Oh well, here's hoping it behaves itself and manages to get to McGraths under its own steam - not on a flatbed.
daverichardson
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Hi Trident Tested
My problem above was eventually resolved (took about 2 weeks to book it in diagnose and fix)
Turned out to be 3 coils had partially failed. So I took the opportunity to have them change all the plugs and coils and it has been fine since!
The symptoms were an intermittent flashing engine symbol on the dash and of course an intermittent lack of power.
You are of course right about accessibility to the plugs, which is why I elected to get them all done at once
Hope you get it resolved
My problem above was eventually resolved (took about 2 weeks to book it in diagnose and fix)
Turned out to be 3 coils had partially failed. So I took the opportunity to have them change all the plugs and coils and it has been fine since!
The symptoms were an intermittent flashing engine symbol on the dash and of course an intermittent lack of power.
You are of course right about accessibility to the plugs, which is why I elected to get them all done at once
Hope you get it resolved
drewf
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I had exactly the same a year ago, thought the problem had been resolved, and it certainly was fine throughout the Modena tour. However... it's back now - always fine when cold, and takes an hour to suddenly decide that 7 cylinders will do. It's interesting that everyone says it was perfectly OK for an hour, then the fault occurs. Since all the plugs were changed on mine, I'm left with the coil packs to do. Had exactly the same engine error message, which went away following a fault reset (not a very useful fault - told me there had been a misfire. No ****.)
TridentTested
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The one hour delay is interesting which points to some sort of heat related problem. As several above have referred to cylinders 7 & 8, I first thought was it might be too hot for the back cylinders but when you look at the engine, although it is fairly well-packed under there, there is nevertheless still plenty of space. It was 10° C on Monday, and with a 70 mph wind at motorway speed, it's hard to see how overheating could be a factor.
Unless some other factor in the chain is getting too hot; does anyone know where on the ECU are the transistors which operate the coil-packs? Could numbers 7 and 8 transistors be getting too hot?
drewf
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Seems unlikely about the ECU getting too hot - the ECU is under the passenger footwell, and I'm not sure it gets that warm down there. That said, I guess the left hand exhaust does run fairly close to the unit, however, it happens regardless of how hard I drive mine. Clearly the engine and exhaust system gets much hotter when being given some beans than just gently cruising on the motorway, and it always takes the same 1 hour, give or take a few minutes or so. Never happened at all over summer, when driven in some pretty high temperatures on the Continent.
I'm pretty certain something gets heat soaked.... I'm just not certain what it is.
I'm pretty certain something gets heat soaked.... I'm just not certain what it is.