mabbo

Hello,

I bought a 1.4 Fiesta Zetec yesterday from a car auction as a cheap run around. Im not to hot when it comes to Fords but know my way around an engine.

Its done 80k miles and seems to be all OK apart from a low rev misfire. At idle it is a little lumpy and when the accellerator is slowly applied the misfire seems to get worse up to around 2k and the car judders. Over 2k it dont seem as bad. When driving you can feel the missfire all the time if you look for it, but at lower revs it is more noticable. Pulling away can be a bit of a pain and requires more revs than it should.

I removed the leads one by one with the engine running and one didnt make any difference. It the 3rd cylinder from the left. I took out the spark plug and it was black and wet. To check the plug, I cleaned it up and put the wet plug in another cylinder and the good plug from that cylinder into the cylinder that wasnt firing. The wet plug fired fine in the good cylinder, but the good plug in the misfiring cylinder didnt make any difference. To test the leads I changed the leads over which again didnt make any difference. I thought that the injector may be faulty so swapped them, again, no difference.

I am now worried that I have a problem with the valves or rings on one cylinder. I will do a compression check if I get time today on all the cylinders.

I have read that the coil pack can cause a low rev misfire, but when I tested the leads yesterday there was a spark jumping between each lead and the coil pack when I removed them one by one so assumed the coil pack was ok?

Can anyone suggest anything else it could be? Im worried I have bought a lemon

Thanks,
Mabbo

Dal_

iTrader: (2)

Faulty coil pack perhaps? Idle Control Valve?

JamesH

iTrader: (21)

I had this on a 1.6Zetec. It was the leads. Chuck a new set of plugs and leads at it - if you have a Halfords trade card, you should get them for just over Ł30

Edit - I just read the whole of your post, coil pack/compression check

mabbo

Thanks for the replys guys

Im gonna do a compression check now and Iv lent my mates coil pack to try.

Also, I just started it up from cold for the first time. It revved up and idled just less than 2k then slowly died down... like an air leak.

Im hoping its not the head gasket.

Mabbo

mabbo

Hello again,

The leads, coil pack and the plugs are all OK and I have low compression on number 3

I done a "cowboy" compression test because my Gunson compresion tester dont fit in the spark plug hole because the threadded section is not long enough. Anyway, I held the compression tester in the number 3 plug hole while I had a helper turn the engine over and the gauge went up a little. Done the same with number 2 cylinder and the difference was massive. I could feel the gauge been forced up from the plug hole and hear the air being forced out of the plug hole.

So, number 3 has low compression which explains why bugger all happens when I remove number 3 plug lead.

I spoke to a mechanic my mom uses and he said he will lend me his tools so i can do a proper compression test and leakdown test. He also suggested I get some engine flush and drop the oil and fill it with fully synthetic as I dont know whats in there. He said that may free up a lifter if there is one stuck.

So, head gasket, bent / stuck valves or piston rings are the most likely causes?

I bet Im gonna end up paying the same as what I spent on the car to get it fixed

I paid Ł500 for an 80k S reg Ghia X with a few dents/scratches. Dont look like I spent wisely

martysmartie

iTrader: (1)

That sounds like a good idea with engine flush, you then need to do an oil change, people use the incorrect oil, with these engines it's CRUCIAL they run on 5/30 otherwise it causes problems not least with sticking valves, clogged oil galleries and oil starvation, I always change all fluids on cars I buy anyway. They have solid lifters so they don't jam unlike hydraulic.

I would do the above as is simple and should be done anyway especially as you don't know history of car, then if still same move onto looking at the bigger things.

Martin

mabbo

Thanks for the reply Martin

Ill give the oil a try, might pop over halfords in a min and pay a fortune for oil. haha.

So the zetec has solid lifters? I assumed they had hydraulic. So the wrong grade, none synthetic oil wouldnt cause sticking valves?

Cheers

martysmartie

iTrader: (1)

Yes as I said above they need to run 5/30 which is semi synthetic, green container if going Castrol.

People use different grade oils etc which on these engines which as I say causes sticking valves, clogged oil galleries and oil starvation.

All Zetec-SE have solid lifters.

Martin

JamesH

iTrader: (21)

Sorry to read this mate. I'd say that it is more likely to be valves/rings because if it was the head gasket, you'd expect 2 or 4 to be slightly low too, if its blown by the fire ring part of the gasket

It may be easier to just get a full engine from a scrap yard if this is the case

mabbo

Right people... bad news I think,

Iv just done a oil flush and change. I used 5/30 semi synthetic and its no better

So, it looks like its valves.

What will be my best bet? Its a shame because it sounds nice and quiet and dont leak any oil... and even though its only firing on 3, suprisingly it drives nice.

What sort of price am I looking at to get the valves replaced? If I was to get a good 2nd hand head and replaced it, is there anything I should be aware off/look for?

Cheers

mabbo

Just done a compression test

From left to right they were - 220, 218, 35, 220