Sparkplug Issues

[Davsurfa]

So I'm driving back from the monthly shopping to trip and the car starts to cough All I can think is what's wrong now?? As I try to accelerate the cough descends in to a mis-fire. To say I was unimpressed doesn't even get close:mrgreen: Anyways, when I stopped at a junction I thought to myself 'Maybe it's a bit of crap in the injectors' so whilst sat still in neutral I plant my right foot, the tacho needle screams in the red line without any effort or hesitations. Being a rather "fresh" night, and I figured a slow journey home, I put the heater on. There was an odd electrical burning smell so my first thought was 'Coils!!!' Atleast it'd explain the mis-fire. So first thing this morning I call the good Doc at RSD, the journey to work was driven on 3 cylinders. Come dinnertime I drop the car in there and left them to it.

At 5 o'clock this evening I collected the car, firing on all 4, no burning smells, problem solved

The coils, leads, plug caps all in perfect working order. The plugs on the otherhand were a little worse for wear. Well, cylinder 2 and 4 plugs were lightly brown and looking good but the plugs in cylinders 1 and 3 were erm.... how can I put this technically... erm.... buggered beyond belief is the best phrase that comes to mind. Here are some pics to show you the state of them.

Plug one:

Plug three:

Now for the question, why and how did my plugs end up like this? What would of caused this? The plugs(all 4) were dry not oily at all. The side electrodes have huge carbon deposits. The ceramic around the centre electrodes has bubbled and melted. The ceramic at the other end is slightly yellowing.

So far I've been told that I'm driving it too hard(It rarely sees the redline), driving it too soft(I live a mile and a half from work and in the recent cold spell the car wasn't getting chance to get off choke), using the wrong fuel, I use unleaded but I should use super unleaded(I thought super unleaded was for sportier cars like scoobs, evos, S3s and the like, not a 1.6 A3), or that I should use octane boosters like redex or NoS additives, again I thought those were for sportier cars than mine.

If anyone could shed some light on the cause I'd appreciate it!! Cheers in advance.

 

[pgarner]

keep and eye on the coils mate, you may find that they might end up going shortly

what 1.6 is it ? the single or twin cam ? the twin is supposed to be run on super but the wifes isnt and the sparks were fine when i changed them, slightly worm but they had done some think like 55k

 

[Davsurfa]

It's an 8v so I assume it's a single cam. Would it do any harm or good to run on super, other than in my pocket. Since it was rebuilt, imo, it pulls like a frieght train(as much as a 1.6i can). It will leave a 1.8(non turbo) from standing start, but I was told by the Doc that it wasn't remapped, just "re-built properly". They admit at RSD that it's "bloody quick for a 1.6".

 

[Davsurfa]

So having posted that it's now running sweet, I get in the car today and it's back on 3 cylinders! Back to RSD I go, new coil fitted, along with the new plugs fitted yesterday and it's still on 3 cylinders. The only bits left that come to my mind are plug caps and leads but beyond that I'm out of ideas.

 

[prevtec]

couple or reasons

the plugs are really old
their the wrong plugs, as in theres certain plugs for different heat range engines
the plugs werent fitted properly,

anyway problem solved now mate

 

[pgarner]

what cylinder is it ? a a guess no3.
try swapping the coils around see if the problem moves to the other cylinder

 

[Davsurfa]

The problem isn't solved, the car is still at RSD. The plugs in the pics are out of cylinders 1 and 3 that are buggered. I figured it can't be the plugs themselves cuz they have all been replaced and it's still only running on 3. The coil that all 4 plug leads start from had a pin snapped off so the coil was replaced and it's still only going on 3. I'm sure the good Doc Danny will weave his magic spanner at it and fix it but I wanna know how to avoid it happening again hence looking for the cause.

 

[obi_waynne]

It looks like they are running too hot. Were they overtightened perhaps when they went in?

Do you have any fragments of the plugs inside the cylinders? This can cause major problems, blow the debris out with a high pressure air line just in case. (Watch your eyes!)

 

[Davsurfa]

Cheers for the tip Waynne, but it would appear that the leads, caps, plugs and coil is all good. The latest theory(from a workmate, also the Doc seemed to think this was a possibility) is that the piston rings are shot or a possible valve problem. If it's rings or valves I won't exactly be happy considering it was rebuilt not 5 months back by RSD.

 

[one in a million]

well i saw a fiesta with that problem and oil got in with the spark plugs, then it needed a new engine, that all i heard about it, so i wouldnt no what that was about

 

[pgarner]

If it's rings or valves I won't exactly be happy considering it was rebuilt not 5 months back by RSD.

Least youd have a warranty

 

[pgarner]

has it actually been diagnosed to see what fault codes its reading ? is its knocking any cylinder, what one is misfiring etc

 

[Davsurfa]

Ha haaaaa!!! Warranty?!? I doubt that but it's worth a try. The engine has been pulled apart and the result........... is......... oil stem seals!!!! I did say it'd been using quite a bit of oil in other threads but tbh it wasn't smoking badly. Apparently the seals are about £1 a piece but it'll take 3hours to fit them!!

 

[pgarner]

so they rebuilt an engine and didnt give a warranty on it ?

 

[Davsurfa]

tbh I never even asked!! It's supposed to be ready on friday so it'll be the first question I ask.