Juddering/spluttering in 2nd and 3rd

[Biscuit]

Usual procedure is to note the fault codes, clear them, drive it around and then rescan to find out which codes reoccur. This rules out any redundant codes from n months ago - they've done that so no problem there.

I didnt drive it around much, probably 2-3 miles in total, would this be enough?

How old is the battery? Does it start ok?

No idea how old it is, i have had the car 2 and a half years and its not been changing in that time but it does start first time every time, even in the cold.

Signs of a dying alternator are slow/sluggish electrics. A quick test is to put your headlights and radio on and then wind your windows down. Assuming they're electric(?) you'll see your headlights/dashlights dim. Obviously that's not the official way but it gives you an idea. DO NOT unplug the battery cables as suggested all across the whole of the inernets.

Well previously i have noticed that when i do the above, the lights dim ever so slightly, but im talking the amount you really have to be staring at to notice.

If you wanted to get technical you could ask the garage to measure the load on the alternator.

Hmm i don't really wanna take it back to the same guys without a really good idea of what it could be because they probably will charge me for any future checks.

[mycarsavw]

I didnt drive it around much, probably 2-3 miles in total, would this be enough?

No idea how old it is, i have had the car 2 and a half years and its not been changing in that time but it does start first time every time, even in the cold.


Well previously i have noticed that when i do the above, the lights dim ever so slightly, but im talking the amount you really have to be staring at to notice.


Hmm i don't really wanna take it back to the same guys without a really good idea of what it could be because they probably will charge me for any future checks.

If it returned that soon, then those are real (current) faults.

Your lights dimming ever so slightly is normal, most cars will do this. It's when they dim a lot that you need to worry. I think that rules out the alternator. A load test would be conclusive though.

Let's see what the codes are, that might give you a better idea of what's going on.

[Sputnik]

They checked the voltage across the battery separately and it was fine

The ECU might not be seeing the same voltage, They should have checked the voltage in live data using a diagnostic scanner. It could be a poor connection in a loom plug or a bad earth connection.

I have the actual printouts at home so i can post up the codes later

Fault codes are not really that accurate, They are a guide only.

A flashing Airbag light is often a bad connection on the seat belt pretensioners under the seats. with the ignition key safe in your pocket, You can unplug them under the seat and squirt a bit of wd40 in the plugs and work them back together to clean the contacts in them.

[Biscuit]

The ECU might not be seeing the same voltage, They should have checked the voltage in live data using a diagnostic scanner. It could be a poor connection in a loom plug or a bad earth connection.

They may well have checked that but i just have no idea exactly what they did.

Fault codes are not really that accurate, They are a guide only.

A flashing Airbag light is often a bad connection on the seat belt pretensioners under the seats. with the ignition key safe in your pocket, You can unplug them under the seat and squirt a bit of wd40 in the plugs and work them back together to clean the contacts in them.

This im pretty sure they did check, but i have my haynes manual so i could give it a look.

What recommendations do you have for proceeding?

[Sputnik]

Hi Guys,

I have an 03 Ford Fiesta 1.6 duratech and for a couple of weeks now it has been juddering a bit between 2-5k revs in 2nd and 3rd. It usually only does it the first few times i accelerate on a journey then its ok.

So it only does it when the engine is cold?

How to proceed? I'd get someone who know what they are doing to use a decent diagnostic scanner and observe the live data on the engine warming up from cold.

As you have a code for low battery voltage I'd be checking the voltage on the scanner in comparison to the voltage at the battery.

The other things that they should be looking at is fuel trim, Lambda sensor status(i.e how long until it goes closed loop) etc.

Can you describe the problem any better ?

[Macman]

I had the juddering problem/car loss of power; turned out to be the coil pack. Which sorted it out for me. Hope you get it sorted soon man

[DanceswithUnix]

Coilover = suspension, Coil pack = engine/spark related

First step would be to have the car checked for fault codes.

In this case I think "coil over" means "coil over plug" ie ignition, rather than "coil over strut". Don't know the car, but having HT coils on each plug seems quite common these days.

[mycarsavw]

In this case I think "coil over" means "coil over plug" ie ignition, rather than "coil over strut". Don't know the car, but having HT coils on each plug seems quite common these days.

T'was a joke, but you're right

[Biscuit]

So it only does it when the engine is cold?

How to proceed? I'd get someone who know what they are doing to use a decent diagnostic scanner and observe the live data on the engine warming up from cold.

As you have a code for low battery voltage I'd be checking the voltage on the scanner in comparison to the voltage at the battery.

The other things that they should be looking at is fuel trim, Lambda sensor status(i.e how long until it goes closed loop) etc.

Can you describe the problem any better ?

Well i wouldnt be too quick to suggest these guys dont know what they are doing, they are a very popular garage in the area!
http://www.six-bay.com/

Well it only seems to do it the first couple of times i accelerate through the first few gears. Its really quite hard to explain in words but its like it will accelerate up to 2k revs, then jerkily hesitate for little bit and almost kangaroo jump. I really dont have any idea how to explain it

[Sputnik]

Well i wouldnt be too quick to suggest these guys dont know what they are doing, they are a very popular garage in the area!

I'll make my own judgement on any garage, I don't care if they have a nice building, A flash website or even a flag on the moon. I only judge them on how well they can repair cars. Too many garages claim to do diagnostic work and do nothing but read codes and act on the codes. Codes are not 100% they are a guide. Just stalling your car will cause a code to be logged for the MAF - It does not mean it is faulty. Just the ECU didn't get what it expected so it logged a code for it.

A local big garage here with hundreds of 'satisfied' customers changed the APP sensor on a focus 3 times in as many weeks because that is what it kept logging codes for and the MAF sensor, Did it cure the problem? No of course not. They had a decent diagnostic scanner, A nice building etc. But, Nobody that really knows how to do much more than change oil and do a bit of mechanical work.

Live data is the real way to find the type of fault you have.

Well it only seems to do it the first couple of times i accelerate through the first few gears. Its really quite hard to explain in words but its like it will accelerate up to 2k revs, then jerkily hesitate for little bit and almost kangaroo jump. I really dont have any idea how to explain it

First of all you need to get the low voltage problem sorted out, Then proceed from there.

[Agent]

I had the juddering problem/car loss of power; turned out to be the coil pack. Which sorted it out for me. Hope you get it sorted soon man

Yup, Fords are notorious for failing coil packs too which is why it was my first suggestion - ticks all the boxes. Given that it's almost 10 year old car, it's hitting the age where they start to fail.

The problem with the coil pack going is that you rarely get any useful data from the logging, as it only has to up the voltage for the spark and nothing else.

Thankfully they are cheap to buy and easy to fit yourself.

The usual quick test for it is to rev the car stationary and see if it splutters. If it doesn't but it does when the car is moving, certainly when accelerating, then the HT pack is often the culprit on a Ford.

It's not a check with 100% certainty, but it's certainly a good indicator.

[Sputnik]

If you do go down the Coil pack route, Buy a genuine one. You don't have to go to Ford for it, You can get them from Andrew Page.

The cheapo after market ones do not last very long.

[Agent]

The motorcraft ones were pretty bad in my experience too Sputnik, often lasting only a year or two. The Lucas ones however were okay and I've not had one of them go yet.

You can often tell from their pricing alone:
Motorcrafts ~ £15/20
Lucas ~ £30/40
Ford ~ £100

That was a couple of years back now, so you'll have to check yourself the current prices, I'm out of the loop.
On a ten-ish year old car, I'd be happy enough with a Lucas. I'd still strongly recommend getting a Haynes though and trying this yourself if you can though

[Tonka777]

Definitely try another coil pack, but consider going to the scrapyard to get a cheap one (or two) to try. If that fixes it you can always buy a new one, safe in the knowledge that that is what is actually needed.

As for the CAN Bus errors, and other juddering, my first thought is a broken/shorting wire, or dodgy plug. If you feel up to it, buy some contact cleaner, then spend an afternoon unplugging every plug, give it a squirt then plug it and out a few times before putting it back. Obviously do one at a time, although you generally have to go some to plug a cable into the wrong hole. While your there, have a poke around all of the loom and see if anything might be rubbing or wearing or through. A short due to a worn wire could be the source of the low voltage code too.

Second thought is engine/gearbox mount. My golf needs a new bottom mount, currently the engine rocks back and forth a little, particularly when coming off the revs, and as the engine moves, the cable gets a tiny bit slacker so the revs drop a touch. This is less likely mind.

As everyone has said, fault codes are only a guide, and even reading live data will only tell you so much. Until an ECU is made which can test the integrity of every cable and every pin in every plug, they are only good for initial checks.

If you're feeling really brave, wash the engine bay. If there is a broken wire, or a weak one, water falling on it will aid the electrons and might clear up your problem for a few hours, until it dries out. Just don't force water into any plugs, the airbox, or the top of the engine. (Not sure if you're plugs are recessed in the head, if they are, and the holes fill with water, the energy on its way to the plugs can jump to earth before it gets to the electrode). - I know it sounds mad, but i diagnosed my old Astra's lack of boost with this method, after trying multiple different sensors and EGR valves and controllers. Took it to the jet-wash one day, and gave the engine bay a bit of a squirt and when i got back in to drive off my ecu light was off and the turbo was whistling!

[Biscuit]

cheers for the help guys, the problem i have is time. I honestly rarely get the time to do these things and any time i do get to myself i tend to spend doing things i actually enjoy!

I will keep you updated as i go

[Agent]

Any luck mate?

I've also found a Ford KA Haynes manual on my shelf that I no longer have a use for, given that I sold it a while back. Yours if you want it for postage?