Mondeo V6 Misfire

[Bowler]

I need some help please

I have an 03 V6 Mondeo Ghia X, which seems to have developed a slight misfire.

Before I take it to Ford/my local garage, I’d like to try and understand what the fault could be. In short I don’t want to be mugged by my local Ford dealer, whilst they chase the fault. If this is simple fault, I can potentially take to my local independent.

Basically the symptoms are it seems to misfire at low revs (1k to 1.5k rpm) – sometimes occasionally, sometimes several times, so that the car judders. The fault clears at around 2k rpm and it then misses again around 4,500 – sort of once or twice. The judder at low revs is not due to incorrect gear selection. All through the rest of the range it seems to run fine

Apart from that, the car runs fine. Fuel consumption is about the same (+/-30ish) with no other problems

The car has 118k on it and has been regularly serviced.

I’m not a techie on these so I’ll won’t understand the complexities of detailed answers, but has anyone any ideas what this could be

Or, is it just best to take it to Ford and get them to plug in the diagnostics?

Thanks in advance

[Kitchski]

Does it do it on idle? Admittedly you can't pull the plugs out one by one and fire it up to see which isn't sparking as you have to remove the inlet manifold to get to them! It'd probably spark as it's cranked over though, so could be worth the leg work. Invest in some new inlet and EGR gaskets ready for refitting though...false economy not to.
If it's not missing when it's idling it'll be a bit trickier, and plugging it in might well be the best financial move in the long run before you spend loads on plugs, coils, leads etc.

But sadly those are the obvious culprits for a misfire. The plugs aren't changed every service (it's every 25k IIRC), but they usually don't fail as long as they were last changed when they were supposed to be. It's been known garages skipping them as they are a bit of a work up to get out. Not difficult, just time consuming.
Leads and coils obviously aren't service items, so either could have failed. If it's a definate miss, then short of an ECU fault I can't think what else it would be. Main thing is try not to let it miss as much as you can. When it missing it boot unburnt fuel down the exhaust into the cat, and unburnt fuel melts catalysts, which starts getting expensive!

[S. Gonzales Esq.]

IIRC, my Mondeo's plugs are on a 60k service interval. If yours are the same then they're about due, and it might be cheaper to get new plugs and leads fitted by an independent than paying for main dealer diagnostics.

I had a similar misfire a while ago and this fixed it for a bit over £100.

Edited by S. Gonzales Esq. on Monday 7th December 21:24

[Zad]

Any local independent should have an oscilloscope to put on the HT leads and coil pack. That would tell you if the coil pack is getting a good signal to start with.

[browser07]

I am haveing a simular problem with my st200 it idles very smoothly and dosent miss at all
but missfires enought to cause the car to judder at 50% plus throttle at between 2000-3000 rpm and dosnt happen above or below that rev range

I have checked the imrc and it is operating corectly

any ideas ?

seemed easyer to post on here than start a new thread

dan

[M-Ster]

Sounds like the common fault that occurs on fords and is the coil pack my friend works for fords and drives around with one in his glove box as they are so common to fault.

[browser07]

thanks
looks like i am swapping my spare one in then 2moro ohh wat fun
dan