Another Mondeo misfire

My daughter has an elderly ('T' plate, 140K miles) 2 litre Mondeo which misfires at low revs. Driven 'briskly' there's no problem, but at anything less than about 2500 - 3000 rpm on a more gentle throttle it seems to lose a cylinder. She has had new spark plugs and leads fitted and has run a couple of applications of injector cleaner through with the fuel, but to no avail. She's had the problem for a couple of months now and it's gradually getting worse. The engine management system doesn't show any fault codes.

It starts easily, and apart from the problem described, runs very well. When it's not misfiring, it doesn't seem to be short on power. She would be really grateful for any suggestions as to what she might do next (as would I !) - bearing in mind that she's unlikely to be able to afford main dealer prices for diagnosis and resolution.

Reply to
Mike Faithfull
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In message , Mike Faithfull writes

Coilpack. About £50-60 and easy to fit yourself.

By the way, I drive a "S" plate Mondeo and I resent you referring to your daughters car as "elderly" ;)

Reply to
Paul Giverin

I drive an N plate Mondeo and resent it as well! Or should that be "resemble" :)

MIght it just be the time of year? As it's getting colder and winter sets in, the moisture in the air could be getting into places it shouldn't be....

Mark

Reply to
Krycek

(snip).

Interesting ... I had considered that, but I thought a dodgy coilpack would most likely be ok under light load conditions and fail when working hard .. ??

Reply to
Mike Faithfull

Is she running it on the proper 'thin as piss' spec oil that Ford recommend for Zetec engines?

Only if you don't run them with this, they can suffer with sticky valves.

HTH

Reply to
jackhackettuk

In message , snipped-for-privacy@yahoo.co.uk writes

The OP has got a blacktop engine with solid lifters. It was the silvertops with hyd lifters which did that if the oil was too thick.

Reply to
Paul Giverin

Checklist for a non-misfire-y Zetec-e :

1) Proper plugs gapped to 1.0mm (not 1.3mm as per book) 2) Genuine Motorcraft leads. Nothing else will do. They are considered a service item and last approx 40-60k. 3) Surface of coil pack should be shiney clean.

I would put a large wager on that that'll fix it.

Tim..

Reply to
Tim..

(snip...)

Thanks for all the replies. I can't vouch for the leads, they were fitted by a "professional", so I presume they are correct as with the plugs and gaps thereof. Maybe I'm too trusting!

Although I still have the reservations about why the problem should show up under light loading only, a close look at the coil pack is clearly indicated. I've asked her to bring the car around today so I can check the current status (no pun intended :-) !!)

Reply to
Mike Faithfull

Yep!

Chris

Reply to
Chris Whelan

Probably.

Ignition loading is at its highest at peak cylinder pressures which on the Zetec E always manifest themselves at engine rpms upto around 2200rpm. You'll probably notice that it is fine when cold, but the misfire gets worse as it warms up.

Tim.

Reply to
Tim..

Further information from horse // er, Daughter's mouth with my added observations ..

- engine starts and idles smoothly when cold (or warm)

- problem does not get worse as the engine wams up

- it only occurs between about 2000 & 3000 rpm and only under light load

- "driven like a boy racer it goes like a train with no problem" (my words - her description involved brown stuff and shovels ...)

- I think she means "taken quickly through troublesome rev range under 'brisk' acceleration it pulls strongly and doesn't falter"

- just checked under the bonnet - leads don't actually have "Motocraft" printed on them, but Daughter reports "they were the expensive Ford ones, not a 'pattern' type"

- top of coil pack is now as shiny clean as reasonably can be without removing it for intensive treatment. No sign of cracks or tracking and it wasn't that mucky anyway.

- removed and replaced connectors onto coil pack and supressor and inside their shields the plug bodies and connections looked as new.

Allegedly a "Ford trained mechanic" has been solicited for advice (via the Old Boy network) and having suggested all the things that have already been done, confesses to being "at something of a loss to explain how the symptoms are like this". I'm now starting to think that the coil pack must be replaced - if only for elimination puposes - and then we've got to consider the sensors that tell the ECU what the engine is up to so that it can deliver the correct mixture with the correct sparks at the correct time to make everything run smoothly. It's probably an expensive exercise, especially on a car of its age and mileage, but apart from this current problem it runs sweetly and is in a generally better condition than might be expected for its age, and probably still has quite a useful working life left yet.

Puzzled of Hertfordshire ...

Reply to
Mike Faithfull

Indeed- the next port of call is a replacement coil pack. You may be able to borrow one through your Ford trained mechanic from Ford, or even try a scrapyard one if possible.

Tim.

Reply to
Tim..

Where did you get that bit from? Previous knowledge? or just the T-reg bit which is about when they swapped?

Reply to
PC Paul

They switched in July/August 1998, "S"-reg.

Reply to
Tony Bond (UncleFista)

Fair enough, but a Mark 2 could easily have been sat around unregistered for a few months... and get a 'T'. Especially with them farting about with six monthly letters for the first time.

Reply to
PC Paul

They introduced the blacktop in May 98 so a T reg is certainly a blacktop. My S reg is a blacktop.

Reply to
Paul Giverin

In message , "Tony Bond (UncleFista)" writes

It was May 1998.

Reply to
Paul Giverin

Sorry, meant to say July/August at the latest (my mondy was built in Aug '98, and has a Zetec-E).

Reply to
Tony Bond (UncleFista)

If this discussion refers to the physical appearance of the engine, then it is indeed black. It has two raised bits running the length of the engine - presumably camshaft covers - and a valley down the middle into which the plug leads connect.

Reply to
Mike Faithfull

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