MK3 Mondeo 2.0 Petrol - Missing a beat

Kona*

Kona*

Kona*

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Newcastle upon Tyne
Hi guys, hope you can help.

Over the weekend my Mondeo has developed a odd fault. When I first start the engine and accelerate it will miss a beat (kind of like misfiring) at around 1500rpm, 1900rpm and 2100rpm - any higher than that is fine, also when the car has done a few miles it will calm down and only do it now and again, and only at 2100rpm. Do you lot have any suggestions as to what it could be?

Spark plugs were changed in May last year and set to the correct spacing (1.3mm) :)

Cheers,

Craig
 
how about the HT leads? Also did you do the spark plug replacement, or do you trust the person who did the change for you? I think that weak or cheap spark plugs can become faulty in a year or two.

EDIT
If the spark plugs and the leads are okay then the next thing to look at is the coil pack.
 
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Cheers for the suggestions :)

I used some "Premium" spark plugs from Halfords and fitted them myself as the previous ones had incorrect spacing (0.8mm instead of 1.3mm)

I'll get a new set of plugs and some HT leads on the weekend, can anyone recommend somewhere that sells decent parts? I don't need performance parts but I don't want them breaking in a year :p

Cheers,

Craig
 
I think the Champion* and NGK spark plugs are okay. Aren't they? That's all my local Halfords sells.


EDIT
* I checked www.fordmondeo.org - it appears that the Champion spark plugs sold at Halfords may be crap.
 
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most people i know with MK3's tend to set the plug gap a bit smaller because 1.3mm cause problems, i know on my MK2 2.0 i set them at 1.1mm with no problems at all
 
99% sure it's the coil pack breaking up.

Also get the ecu scanned for fault codes. I'm surprised the misfire hasn't thrown a MIL yet.....
 
Missfire consistent across the rev range = Spark plus
Random missfire or when it's damp = Leads
Missfire at low revs dissapearing at high revs = Coil pack
Missfire at only high revs = Crank position sensor.

I stand by my "99% it's the coil pack" diagnosis.

Getting an ecu reader on it will more than likely find the issue, although it'd take me a side of A4 to tell you what to look for once the codes are read so I'm not going to bother.
 
Thanks to everyone for the help - I'll be replacing the coil pack first on Saturday and if that doesn't fix the problem I'll replace the HT leads, then plugs :)

I'll update this post when I've replaced the coil pack.

Cheers,

Craig
 
Kona* said:
Thanks to everyone for the help - I'll be replacing the coil pack first on Saturday and if that doesn't fix the problem I'll replace the HT leads, then plugs :)

I'll update this post when I've replaced the coil pack.

Cheers,

Craig
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you're doing the same things i would so hope it works out. :)
 
Kona* said:
Thanks to everyone for the help - I'll be replacing the coil pack first on Saturday and if that doesn't fix the problem I'll replace the HT leads, then plugs :)

I'll update this post when I've replaced the coil pack.

Cheers,

Craig
Click to expand...

Hi - did you replace the coil/HT Leads and did it fix your problem?
 
amigafan2003 said:
Missfire consistent across the rev range = Spark plus
Random missfire or when it's damp = Leads
Missfire at low revs dissapearing at high revs = Coil pack
Missfire at only high revs = Crank position sensor.

I stand by my "99% it's the coil pack" diagnosis.

Getting an ecu reader on it will more than likely find the issue, although it'd take me a side of A4 to tell you what to look for once the codes are read so I'm not going to bother.
Click to expand...

That's not really correct though is it. I had a bad misfire with low revs and high load, by your definition that means a bad coilpack. In actual fact a set of plugs fixed it completely.
 
Clarkey said:
That's not really correct though is it. I had a bad misfire with low revs and high load, by your definition that means a bad coilpack. In actual fact a set of plugs fixed it completely.
Click to expand...

I had that as well, low revs and the miss would occur but 3k upwards it was fine, new plugs solved it.
 
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