Servicing Question - Plugs or not?
Discussion
I had exactly the same circumstances as you.
A couple of plugs were inspected and still looked perfect.
Not changed. Probably does not cost much, but why throw items in good condition.
A keeper, so I do whatever is considered necessary.
Some fluids are even changed more frequently, than the service schedule stipulates.
Just for general information which may be relevant to your car.
The rear bank of plugs on my old Ford Duratec V6 engine are an absolute sod to replace. Intake manifold off etc. So I didn't bother, believing that at under 100,000 miles they should be good for another few miles.
Over time the plug gap widens due to normal wear making it harder for the spark to jump the gap. This puts an undue strain on the coil on top of the plug causing it to start arcing inside the coil. This causes a large back EMF, which fried the IGBT's inside the PCM.
So we've gone from a few bucks to change the plugs to replacing the 6 coils and having the PCM sent off for repair.
And I still had to change the plugs.
The rear bank of plugs on my old Ford Duratec V6 engine are an absolute sod to replace. Intake manifold off etc. So I didn't bother, believing that at under 100,000 miles they should be good for another few miles.
Over time the plug gap widens due to normal wear making it harder for the spark to jump the gap. This puts an undue strain on the coil on top of the plug causing it to start arcing inside the coil. This causes a large back EMF, which fried the IGBT's inside the PCM.
So we've gone from a few bucks to change the plugs to replacing the 6 coils and having the PCM sent off for repair.
And I still had to change the plugs.
OP you really need to say what type of AM you have as the answer will differ.
If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this dust will get ingested and wreck the engine.
If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this dust will get ingested and wreck the engine.
Edited by paulrog1 on Tuesday 23 March 18:26
paulrog1 said:
OP you really need to say what type of AM you have as the answer will differ.
If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but the from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this will get ingested and wreck the engine.
Thanks .i wont sleep tonight!If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but the from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this will get ingested and wreck the engine.
Edited by paulrog1 on Tuesday 23 March 17:18
paulrog1 said:
OP you really need to say what type of AM you have as the answer will differ.
If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this dust will get ingested and wreck the engine.
Having read that, it is (thankfully) a V8 Vantage (2014 model).If you have a V12 you need to know the real time misfire count, that can be found when you visit a garage with AMDS, that should give an indication of any coils misfiring.
Even though your car is low mileage it's not the mileage but its the time the engine has run, for example city driving, that is the factor on sparkplug wear.
Plus the coils do wear quite quickly due to heat soak as the V12 gets very hot and the coils are deep in the engine so the electrical insulation around the coils break down.
On the V12 be very careful of Cat ingestion so you need to take this seriously because if the cat is damaged because of coils failing and excessive misfires and gets ingested your engine will probably need replacing, (around £15,000 last time I looked)
Plus don't think your car is not misfiring by driving it on a motorway and it feels nice and smooth, because there are 12 cylinders if you have a badly misfiring cylinder you won't feel it as the other 11 will smooth the power output, but from that cylinder the cat will have unburnt fuel now on the cat surface and now damaging the cat, this dust will get ingested and wreck the engine.
Edited by paulrog1 on Tuesday 23 March 18:26
And many years ago, with my 2006 V8V a well known Indy (beginning with the letter T) said I ought to change them at 7 years. Who's right or who's wrong? I would have thought main dealers would jump at every opportunity to increase their service billing but it seems like the Indy's are doing just that (assuming it's not necessary to change them at 7 years).
oilit said:
johnc61 said:
I have a 09 vantage which has covered 14400 miles . Aston works service said it was not necessary to change the plugs .
I have a similar age DB9 with 28k and Works told me this year that they didn't need doing.I think the concern is if they've been sat in the heads for 7 years they my get stuck in there, rather than milage related erosion? I've had some heart-stopping moments on older kit.
Not a very helpful suggestion if you're paying someone else to do it, but I'd have thought removing a couple to inspect and if there is no erosion, gaps etc all good, just loosen and re-tighten them all? And if you're doing that why not replace with new, but use the the NGK parts not the Aston branded ones, if the same as the V8.
Not a very helpful suggestion if you're paying someone else to do it, but I'd have thought removing a couple to inspect and if there is no erosion, gaps etc all good, just loosen and re-tighten them all? And if you're doing that why not replace with new, but use the the NGK parts not the Aston branded ones, if the same as the V8.
vernierMike said:
I think the concern is if they've been sat in the heads for 7 years they my get stuck in there, rather than milage related erosion? I've had some heart-stopping moments on older kit.
Not a very helpful suggestion if you're paying someone else to do it, but I'd have thought removing a couple to inspect and if there is no erosion, gaps etc all good, just loosen and re-tighten them all? And if you're doing that why not replace with new, but use the the NGK parts not the Aston branded ones, if the same as the V8.
There was a time when I'd happily have (and did) undertaken such a task. In fact I completely stripped and rebuilt the last V8 I owned, but that was 40 years ago and a far simpler time.Not a very helpful suggestion if you're paying someone else to do it, but I'd have thought removing a couple to inspect and if there is no erosion, gaps etc all good, just loosen and re-tighten them all? And if you're doing that why not replace with new, but use the the NGK parts not the Aston branded ones, if the same as the V8.
Old Chimer said:
There was a time when I'd happily have (and did) undertaken such a task. In fact I completely stripped and rebuilt the last V8 I owned, but that was 40 years ago and a far simpler time.
Totally get that, I'm still enjoying some of those challenges, but I'm getting more selective, and some things are now done by the pro's, just had the Merc sunroof fixed as I really couldn't be bothered with all the headlining malarky. And anything to do with paint....Gassing Station | Aston Martin | Top of Page | What's New | My Stuff