Cylinder misfire

[SevenR]

Hi folks.
Got a misfire in Cylinder 7. So I thought the coil must be goosed, Bought a new one from Euro car parts (aftermarket one as only them in stock) and swapped it but still the same. tried the old coil in another cylinder and its working fine.
I had new plugs put in at the full service in June, so I'm wondering if I've got a faulty plug? Not got the tools to swap them about unfortunately to see.
My MAF though is also goosed I think. So I need to change that out first and then take it from there.
Anyone else had experience on this type of thing happening before?

cheers

[SevenR]

ok, so the MAF has been swapped for a new one. So that's taken care of that and also got the yellow traction control light out which was permanently lit. Yeah!!

I can only assume this problem is a spark plug, cause after that what else could be causing it?

[SevenR]

Ok, Update time.
Got a new plug this morning from ECP. Took out the old one and it is totally black and coked up. Put new plug in, and started up. Misfire gone but big plume of blue smoke out the exhaust. Obviously buring oil which is in the bore.
About 2 weeks before I went to Le Mans in June, the car started using oil quite badly. It would not use any for a while then use loads. No rhyme or reason to it. So we thought the valve stem oil seals might be away on it. As a quick fix we put in a treatment that softens the seals as we thought that might have been an issue. It never sorted it.

When my friend and I were poking around the engine on the hunt for the misfire, I noticed some oil coming out from around the rocker cover on the side of the engine that cylinder 7 sits on (right bank). So I can only guess that i'm losing oil through there, and also into cylinder 7 itself. This has resulted in the spark plug shutting down over time.

The real extent of what's up won't be known until I can get the car to the garage for them to open it up and see. So no point in speculating at the moment.
Not the best news though I have to say. The car is also showing slight misfires on other cylinders, so it could all be connected.

Watch this space for updates.

[SuprSi]

The rocker cover gasket won't be leaking much as it's not under any pressure and will just be seeping. Also no oil can get into the cylinders if that gasket fails but it can get to the top of the plugs, under the coil packs potentially.

My thoughts would be more with the oil separator playing up and letting loads of oil into the intake which is fouling up the plugs and causing the mis-fires.

Also, don't put any additives in the oil, they're pretty much all snake oil and could potentially cock your engine up.

Hope you get it sorted soon.

[SevenR]

I think you might be right here SI, as this has been ongoing since before I went to Le Man in June. It started using oil in a strange way and we couldn't pin point the problem. At least I'm hoping you're right....
I also erased the codes yesterday which is the first time since replacing the MAF and to my shock, the yellow emmisions light which has been on since the day I bought the car has stayed off. So all along, has this just been a faulty MAF??? I took it to several garages who narrowed it down to possibly the cats needing replaced.
What a fickle car. Fingers crossed

[SevenR]

so quick update for you. The rubber gaskets were goosed and brittle, oil was seeping into the cylinder. All sorted.
Cats are knackered though, so rather than replacing them, what are the options?
Cars doing in a power of fuel so need to change a.s.a.p. 200 miles to a tank at the moment as opposed to 300 odd. thank God the price of fuel is down at the moment.

[ASC]

If you can handle the noise bin all 4 cats for straight pipe.

[SevenR]

How do you get past the MOT though mate?

[geordie jay]

blinkin heck 300 miles to a tank...???? the best I had is 220 haha

[ASC]

You'll have to swap them out for the originals every MOT if you can't find a "friendly" tester!
Is it the pre cat or the main cat that's fuct? If it's the pre cat you could bin them/gut them (piggies) and keep the main cat which will still give you a bump in power and should still pass emissions. You'll either need to use 02 spacers or map out the CEL which you will get as the car will think the Cat is fuct with the increased flow. If you don't want to go cat-less (which is the cheapest way and best bang for buck performance wise) you could look at high flow sports cats but they'll be pricey I would have thought.
Depends what you want to do, is your goal more power? More noise? Or do you just want to fix knackered cats? Do you have a cat back already or is everything stock?

Check this for piggies..
http://www.audizine.com/forum/showthrea ... EL-amp-FAQ

Loads more info on this and other options on Audizine.

[SevenR]

All stock at the moment. I have decided to gut the pre-cats (that's the problem). My mechanic can change the settings in the ECU using Vagcom so the car doesn't keep thinking it's fooked and the light will go out.
So more power hopefully, and a better noise too I'm thinking?
Cheers for your input. Let you know how I get on.

[SevenR]

One word. Awesome!!!
Pick up is amazing and the car feels so much more powerful. The noise is a bit better in the inside of the cab, but you'll all know as I do the cab is very insulated from the outside sound, so outside is way better sounding too.

Recommended without a doubt.

[marc1]

Are all your problems now rectified by gutting the pre-cats?

[ASC]

Cat back and JHM tune next and that's you done!

[SevenR]

All sorted Marc although I did have a lot of engine work done before this.
I was sold a lemon in my opinion. No thanks at all to Ron Hodgeson Cars in Up Holland.
An interesting and rather puzzling fact though. When the mechanic went to all the bother of dropping the exhausts down to get the precats out (and it was a lot of work) he discovered that someone has done this before on my car, but only gutted one of the pre cats??? Maybe they thought as it was only showing a fault code on one side, they would strip that one? Who knows.

I'm spending no more on it ASC. That'll do for now. Although the brakes have never impressed me......... lol!!