MK6 Fiesta 1.4 hesitant at low revs.

[TheFinners]

I've recently bought a 2004 Mk6 Fiesta 1.4 as a first car. I am still learning to drive but having driven it a couple of times and also had my parents drive it a couple of times we've started to notice the issue.

Basically under ~1500rpm the engine is pretty hesitant and 'lumpy' when under almost any load, definitely more so than it should be. There also seems to be a strange sound from the exhaust at low revs to accompany it. It seems very strange as once over 2000rpm the engine is fine, pulling smoothly and quietly. The car also had a full service and MOT done before I purchased it last week and has only been driven a few times since then.

If anyone could give me some advice as to what the issue may be and also how much it can cost to sort out it would be appreciated greatly!

[Zad]

I would take the spark plugs out first and have a look at them. Make sure the gap is okay and they aren't worn, but also check they aren't coated with carbon. Fiesta coil packs do have a habit of breaking down sometimes, so that is a possibility.

[SteBrown91]

As above the prefacelift mk6s were notorious for leaking washer jets, which pours fluid all over the top of the engine and into the plugs/leads. It's also quite likely that leads/coilpack have never been changed so I'd look into getting a set of plugs, leads and coilpack as a matter of course.

[TheFinners]

Sorry for being slow to reply but thanks for the suggestions. I had the cambelt changed yesterday as it had reached the 10 year interval and the garage also had a look at the engine. They found a lot of water around the spark plugs, so I would assume that leaky washer jets are to blame. Since the garage had already taken some of the car/engine apart to change the cambelt the water was cleared out for free. Anyway, the car runs much better now, only has some very minor hesitance, but this is barely noticeable in normal driving, whereas before it led to a few eye opening moments on busy roundabouts! I'll still need to look into sealing the washer jets better, Stebrown91 do you know specifically what was changed on the facelifted models to stop the jets leaking?