Duff Plugs - (and an aside on dodgy car speedo! lol)

[Hedgetrimmer]

Just took the car in for a service today. Went to pick it up, taken through the bill, no nasty surprises, about the cost I expected, all seemed good. Driving away though, to find it's running on 3 (4 cyl car). So I take it straight back. Probably a dodgy new spark plug, they say, handing me the keys to a courtesy car. Sorry, no one available to look at it straight away (!).

Now, having worked in the bike trade for some time, I have seen this happen before. Judging by the way they immediately suspected a dodgy new plug, it seems that it must happen a fair bit (although not confirmed yet). On the car, they used Ford plugs, so don't know who the actual manufacturer is. So why did the cynic in me immediately think, bet they're made in China now? Not entirely fair probably, but it got me to wondering just how common is this these days? How many of you have had this happen? (car or bike). And is it a more recent phenomenon, or has this always been quite a common thing?

[taylor]

perhaps they did not change them, hence giving you the courtesy car so you wouldn't see the old duffers coming out as they would have to change them in front of you. only an idea.

[Dead Eye]

Can't say I've had any issues with my mechanic... but my mechanic is me...

Thinking about, I've actually never had any vehicle I've owned serviced by anyone except myself

[locksmith]

mmmmmmmmmmmm duff beer

[rayburn600]

When I was running my workshop I only used Bosch plugs.
Looked closely at the plug made in Brazil.


Whot...I thought they were made in Germany....


Saying that, I cant remember when I last had a duff new plug.

[Hedgetrimmer]

perhaps they did not change them, hence giving you the courtesy car so you wouldn't see the old duffers coming out as they would have to change them in front of you. only an idea.

Of course, that's always a possibility, and I've yet to hear their verdict anyway. My father has been trusting them for 6 or 7 years, and apparently my brother for some time before that, who is generally a bit switched on when it comes to cars. I tend to make judgements not on first experience, unless it's really obvious, and maybe that's a mistake on my part. But as I said, there was nothing on the bill that you wouldn't expect, and the prices for what there is all seemed about right - they wouldn't gain much by not changing the plugs.

My question stands anyway. A common thing or not? A recent thing or not? It does happen genuinely; as said, seen it myself when working in the bike trade.

[chaz]

I used to change the plugs in cars every 6,000 miles and the points every 3,000, the old cortinas were bad to start if you didn't.
had a plug fail in a bike once, as it was a single that was a long push home, a lot of people used to carry a spare plug. Done 33k on the bike and so far no problems but I'm changing them soon, a friend had one fail at 31k but so far never had a new plug go.

[BBROWN1664]

I serviced the wifes focus last year. Put new plugs in and it was running on 3 where as before it had been fine. Turned out to be a knackered coil pack that gave up the ghost due to the new plugs.

[Hedgetrimmer]

I serviced the wifes focus last year. Put new plugs in and it was running on 3 where as before it had been fine. Turned out to be a knackered coil pack that gave up the ghost due to the new plugs.

Aaaargh! Yes, Ford Focus 1.8! I hope coil packs aren't dear on these then.
BBROWN, your wife's car ever had any speedo problems?

[tony_d123]

Like everything else, there seems to be lots of fakes/copies about now. Maybe they have bought some "bargain" plugs off the internet?

[BBROWN1664]

it was about 40 quid from memory from euro cat parts
No problems with the speedo though

[esetest]

Quality control does seem to be a bit of an issue now especially over the last few years , in my industry , for example  brass bolts are softer and strip very easily , steel bolts seem to be softer , trunking seems to be thinner , tray is like foil , the slots in socket screws are shallower , the plastic on new consumer units is very soft , and lots of dodgy cable out there  . 

[limax2]

A mate put new plugs in his Fazer 1000 last year and said it didn't feel right, so he put the old plugs back in and it was good again. May have just been one odd faulty plug, but he didn't bother to find out. Or as said before maybe there are substandard plugs in the market place.
If it is a plug problem I think they probably changed the plugs on your car as it is unlikely one would have chosen to pack in just after a service. 

[robby boy]

I change quite a lot of plugs in a year, nearly always Bosch or NGK, never had a problem, depending on what age your Focus is the mechanic could have damaged the plug lead when he was changing the plugs, coils do give problems to on that model. I think they have changed the plugs though as the car was on 4 when you put in and it is obviously not now.

[Lank]

I serviced the wifes focus last year. Put new plugs in and it was running on 3 where as before it had been fine. Turned out to be a knackered coil pack that gave up the ghost due to the new plugs.

Aaaargh! Yes, Ford Focus 1.8! I hope coil packs aren't dear on these then.
BBROWN, your wife's car ever had any speedo problems?

what year is your focus? I assume the speedo just drops to 0 and comes back now and again.


I had a 2002 and the common problem is the speed sensor on the gearbox. Annoying job as they normally snap off on the gearbox. The part is only £25 from ebay.


I had it replaced and was fine, my step father has the car now and had to fit a new gearbox, the speed sensor on that box had gone too.

[tony_d123]

There seems to be quite a few fake NGK plugs about, here is how to spot them...

http://www.slideshare.net/athangal/distinguishing-fake-ngk-spark-plug
http://www.ngk-sparkplugs.jp/english/techinfo/fake/

[Hedgetrimmer]

I serviced the wifes focus last year. Put new plugs in and it was running on 3 where as before it had been fine. Turned out to be a knackered coil pack that gave up the ghost due to the new plugs.

Aaaargh! Yes, Ford Focus 1.8! I hope coil packs aren't dear on these then.
BBROWN, your wife's car ever had any speedo problems?

what year is your focus? I assume the speedo just drops to 0 and comes back now and again.


I had a 2002 and the common problem is the speed sensor on the gearbox. Annoying job as they normally snap off on the gearbox. The part is only £25 from ebay.


I had it replaced and was fine, my step father has the car now and had to fit a new gearbox, the speed sensor on that box had gone too.

Well, it's on a 54 plate. Yes, the speedo drops to zero now and again, for a few seconds at a time. Also, the odometer light flickers now and again. Have been told that it's a common problem and can spread through the display like a cancer (!). Not a problem at the moment, as it is only for a few seconds at a time, but will be keeping an eye on it to see if it deteriorates.

Apparently, did have a dodgy plug, delivered back today, all ok so far. So hopefully won't need a coil pack, fingers crossed!

[BBROWN1664]

if its running fine now the coil pack will be ok.

[Lank]

I serviced the wifes focus last year. Put new plugs in and it was running on 3 where as before it had been fine. Turned out to be a knackered coil pack that gave up the ghost due to the new plugs.

Aaaargh! Yes, Ford Focus 1.8! I hope coil packs aren't dear on these then.
BBROWN, your wife's car ever had any speedo problems?

what year is your focus? I assume the speedo just drops to 0 and comes back now and again.


I had a 2002 and the common problem is the speed sensor on the gearbox. Annoying job as they normally snap off on the gearbox. The part is only £25 from ebay.


I had it replaced and was fine, my step father has the car now and had to fit a new gearbox, the speed sensor on that box had gone too.

Well, it's on a 54 plate. Yes, the speedo drops to zero now and again, for a few seconds at a time. Also, the odometer light flickers now and again. Have been told that it's a common problem and can spread through the display like a cancer (!). Not a problem at the moment, as it is only for a few seconds at a time, but will be keeping an eye on it to see if it deteriorates.

Apparently, did have a dodgy plug, delivered back today, all ok so far. So hopefully won't need a coil pack, fingers crossed!

There is the other problem of the dials failing and you need a replacement. If when the speedo drops of the car runs a bit lumpy on acceleration it will be the sensor, as the car thinks it is stationary. Mine would normally stall coming to a stop unless you blipped the throttle and also very lumpy and low revs

[Hedgetrimmer]

There is the other problem of the dials failing and you need a replacement. If when the speedo drops of the car runs a bit lumpy on acceleration it will be the sensor, as the car thinks it is stationary. Mine would normally stall coming to a stop unless you blipped the throttle and also very lumpy and low revs

Ah, funny you should mention that. A couple of times I've thought it got a bit sluggish, momentarily, with the loss of speedo, but wasn't sure if it was my imagination (only happening when off throttle at v/low speed, e.g., slowing for junction/roundabout/ v. slow traffic etc). Normally, if I put my foot down again (where possible of course), the speedo picks up again and no sign of hesitancy. Well, I'll see how it goes for a bit, and if it gets worse, looks like it'll be up for a new speedo sensor then. Thanks for the tips.

All ran fine today.