Hey guys,

My 2001 Fiesta 1.25 zetec is running on 3 cylinders, at least that is what it sounds like. Its unbalanced, different sound tone and the engine light either stays on or blinks.

I took the engine coolant cap off and let the car warm up in idle, but saw no bubbles of any kind, which I've learnt is a good gasket leak test, then again what do I know! I've checked the spark plug connections which seem all good.

It is due for maintenance, including a spark plug change, but are there a few other tests I can do to verify a few things?

Prefer to not get too ripped off taking it to a garage so the more I can rule out without killing myself, the better!

Cheers

Probably a very bad misfire. I believe the check engine light flashes if there are more then a certain amount of misfires detected in a certain period of time. Where I live, you can borrow a code reader from many auto parts stores. If there is a place that does that where you are, i'd go for it and see what code is being thrown.

Is your engine coil-on-plug? If so, it's probably either the coil or the plug that's bad. If it isn't coil-on-plug then it's probably a wire or plug. Though there's always the possibility that it's losing a lot of compression somehow.

It's hard to diagnose a car over the Interwebs, but I shall try to give some advice that will hopefully be of some help.

Right, the first thing I would do is take off the HT Leads, and have a look at the Spark Plugs. Take them out, and have a look to see what colour they are, be it black or miscoloured. If need be, replace them before you have the service and just tell the garage not to replace them when it goes in. PLEASE NOTE though. If the old spark plugs are fine and you want to put them back in, DO NOT put too much force on the wrench. Just do them up firmly. When fitting new ones, keep turning them until you feel the washer press together with the cylinder head, then give them another 1/4 of a turn.

If the spark plugs turn out fine, then the next thing I would check is the Ignition Leads and Distributor. Quite simple. For the HT leads, look at either end and along the leads for any cracks or splits. Pay special attention to the inside of the ends as they may of broken away. For the distributor, unscrew it (take note of the HT Lead order first!) and look inside it for cracks, and check the contacts for any dirt or corrosion.

The only other thing I could suggest you check yourself would be the Vacuum pipes on the Air Intake Manifold, Throttle Body etc, but these usually cause the whole Engine to run lean, and not one cylinder to misfire. Worth a try I suppose?

Apart from that, you would need Garage equipment to check other things that could be causing the misfire. It could be anything, from Injectors, to fuel lines (You could inspect these yourself, but it would be pointless as you won't be able to tell much) and many other things. I would suggest just trying as many of the things you can think of.

Oh! I forgot to ask. Is the Engine smoking at all? Also, is there any white, mayonnaise type "goo" in the Header tank? If the car is puffing white smoke, this is either a sign of Headgasket failure, or moisture in the exhaust due to the car being stood a long time. Blue smoke is petrol, and black is oil.

@ Hummer. It uses Leads.

Ecu light could be a sensor (most likely) Might the the O2 sensor or some kind of MAF sensor not reading right so the mixture and timing are totally wrong hence causing the bad running.

Take your plugs out, check their condition and any deposits on them.

Check there is a gap and that is the same on each plug, modern plugs are nearly always pre-gapped correctly so I wouldn't worry about measuring it if you don't have a set of feelers ready, it is possible that bits of debris in the engine can hit the tip and reduce the gap (I got away very lightly when the Lada deposited a nut from its carb into the engine and other than regapping one of my plugs didn't seem to cause any harm, maybe it's still jammed in there somewhere ).

Rub them down with a wire brush and always give them a wipe down or use an air line to blow off any bits of grit before you put them back in. Then rest each plug so it is earthed (ie. touching the block) and crank the engine over, look for the sparks and if one is weaker than the others you've found the problem.

If it was me, and i know it sounds dangerous, probably because it is, a little bit, but anyway, find yourself a good pair of insulated pliers, might also be worth wearing some thick rubber gloves too for double insulation, start the car, and pull one lead off at a time using the pliers, if the engine note drops and it runs worse, then push the lead back on with the pliers and keep checking the others, until you pull one of them off and nothing changes, and there you have it, you found which cylinder it is, which is a start!

You could check for a spark by taking each plug out at a time by grounding the metal casing of the sparkplug and seeing if it sparks.

I would start by checking the spark plugs seeing as they are the easiest, (and quite a common proble)...if you want to check to see if your head gasket is about to go open the oil filler cap and check for white goo on it.
if none of those you might want to check your ignition wires and cap (not sure about the fiesta) for corrosion breakage etc...and lastly it might possibly be a blocked injector.

Quote from danthebangerboy :

If it was me, and i know it sounds dangerous, probably because it is, a little bit, but anyway, find yourself a good pair of insulated pliers, might also be worth wearing some thick rubber gloves too for double insulation, start the car, and pull one lead off at a time using the pliers, if the engine note drops and it runs worse, then push the lead back on with the pliers and keep checking the others, until you pull one of them off and nothing changes, and there you have it, you found which cylinder it is, which is a start!

i've done that before... but it only works if the distributor contact points are good, along with the wiring.

@Neils - have you checked your timing?

Niels breng hem naar de garage als je een auto hebt moet je automatisch ook garage kunnen betalen zo niet, doe de auto weg.

Trabslation: Niels bring your car to the garage if you have a car you should automaticly have the money to bring it to the garage if not, sell the car.

Quote from bunder9999 :

i've done that before... but it only works if the distributor contact points are good, along with the wiring.

I've also done that before. Let it be known, the possibility of your hand automatically punching the hood of your car harder than you have ever punched something in your life is there. I thought I broke my hand when the juice caught me and my entire arm jerked upwards ramming my hand into the hood (bonnet).

Quote from Chrisuu01 :

Niels bring your car to the garage if you have a car you should automaticly have the money to bring it to the garage if not, sell the car.

What a load of bull.

I'm sure like most people who own a car, he can afford to maintain the car but will occasionally like to have a go himself to save some pennies. Heck, if he has the confidence to give it a shot, why shouldn't he?

It's a shame you don't even have the common sense (Or maybe you just lack any knowledge about cars??) to have a look yourself, before handing it over to the money grabbing grease monkeys who can barely hold a spanner, let alone repair a car.

Quote from Nathan_French_14 :

It's a shame you don't even have the common sense (Or maybe you just lack any knowledge about cars??) to have a look yourself, before handing it over to the money grabbing grease monkeys who can barely hold a spanner, let alone repair a car.

+1

Diagnosing a problem and then fixing it can not only be challenging but also fun.
It saves you cash and you can look back on it and go "**** yeah, i fixed that!" and feel proud about it

Quote from Nathan_French_14 :

What a load of bull.

I'm sure like most people who own a car, he can afford to maintain the car but will occasionally like to have a go himself to save some pennies. Heck, if he has the confidence to give it a shot, why shouldn't he?

It's a shame you don't even have the common sense (Or maybe you just lack any knowledge about cars??) to have a look yourself, before handing it over to the money grabbing grease monkeys who can barely hold a spanner, let alone repair a car.

I have a garage full of motorcycles which I own together with my dad.
He also has some old cars that we work on so I do have knowledge.
I just don't really know how to do the real difficult problems like when your gearbox is broken or when the electrics are faulty.
The rest I know how to mend it.

And I think this is a electrical problem no doubt the problem with the lights is just to suspicious

Woah loads of replies! I'll make sure to read the lot and decide what to do.

Thanks!

or buy something like this http://cgi.ebay.co.uk/Car-faul ... iagnostic_Tools_Equipment and simply find out what fault code is bringing the ecu light up.

Checking if the misfire is isolated to one cylinder will narrow down the problem quickly, so the pull leads off an see if engine runs the same or worse test is good for seeing that, as mentioned above.

An easy way to check ignition leads is to pop the hood with the engine running at night, leaking high tension voltages will be pretty obvious in the dark

Many times they break down where they are near or rubbing on other metal objects, if that is causing the misfire you can temporily rectify it with either electrical tape or holding it away from the object it is shorting too. Other reasons can be just built up grease and road grim which creates a path for a short.

@mrodgers my dad was an evil character and used to hold onto a plug lead with the engine running and say come have a look at this! When I approached eager to learn about mechanics he would reach out and touch me and KAZAP! That's where I learnt about high voltages

A vaccum hose that has been dislodged (or is just old and often the vacum hoses split where they connect) can cause one cylinder to misfire if it is near the inlet of that cylinder which I have see before. I've even seen a car running like a dog and all it was, was the nuts securing the inlet manifold had come loose, on realising that I bought the car on the spot ($175) drove it around the corner tightened up the manifld bolts and it ran like a swiss watch for another two years without me spending a dim on it .

Thats the cheap ones

If you have bubbles in your water, execive exaust gas pressure coming out of the oil filler cap (check you oil if water has mixed with it you will see white slurry after running the engine) or moisture and water spitting out of the exhaust it is likely to be a head gasket or hole/corrosion in the head.

A burnt or pitted valve can cause an engine to run rough also which can be caused by a cylinder that is running too lean (such as a vacum hose dislodged/disconnected)

Quote from Niels Heusinkveld :

Hey guys,

My 2001 Fiesta 1.25 zetec is running on 3 cylinders, at least that is what it sounds like. Its unbalanced, different sound tone and the engine light either stays on or blinks.

I took the engine coolant cap off and let the car warm up in idle, but saw no bubbles of any kind, which I've learnt is a good gasket leak test, then again what do I know! I've checked the spark plug connections which seem all good.

It is due for maintenance, including a spark plug change, but are there a few other tests I can do to verify a few things?

Prefer to not get too ripped off taking it to a garage so the more I can rule out without killing myself, the better!

Cheers

which engine is it ( is it mk 3-4-5 ?? these little bangers get a hard life... )

have you checked at Every cable is connected correctly ( noobish statement, but you'd be surprized hwo often this can be a fault... )

So, Neils...

Any updates on how this went? I'm intrigued as to what the problem was.

A: Just get the ecu diagnosed - should have an error code.

If you don't want to do this .......

B: Replace plugs first, suprising how often plugs fail.

C: Replace HT leads.

D: See A

Quote from bunder9999 :

i've done that before... but it only works if the distributor contact points are good, along with the wiring.

@Neils - have you checked your timing?

Not really, if the coil pack is knackered then you'd still get the same thing happen. But then to rule the coil pack you do the same thing on the other side, but instead you're looking for a spark bridging the gap. If the spark is there the problem is plug or lead. If it isn't you need a new pack. Assuming the aforementioned test shows one of the cylinders isn't getting a spark.