Spark plug gaps

[AJP]

Following on from my misfire issues which a few of you have been advising me on:

http://www.mk5golfgti.co.uk/forum/index.php?topic=108462.msg1050359.msg#1050359

I'm going to pull the plugs tomorrow, hopefully. Assuming I can get hold of a set of plugs before then - Bosch 101 905 631H or NGK BKR7EIX (they're the right part numbers aren't they?)

Will they need gapping, and to what? I think I've read that the NGK plugs come already gapped, but for a standard car? Car is Stage 2 k03.

[rich83]

No. Just throw them in. 

[AJP]

No. Just throw them in. 

Ta mate. I've got a feeling new plugs will cure the symptom rather than the cause, but we'll see!

[bonelorry]

Don't fit the Bosch plugs, NGK BKR7EIX or the OEM NGK ones.

As said just throw them in, They are pre-gapped and if you try to re-gap them you can break off the Iridium coating!

[AJP]

Ok, just been trawling local places for the NGKs and got some BKR7EVX. They said they were superseded by the BKR7EIX but are the same. Just bought them, not really thinking.

However, it says PLATINUM on the box. Not... iridium. F*cks sake. Should I be taking them back or will they work?!

[bonelorry]

Ok, just been trawling local places for the NGKs and got some BKR7EVX. They said they were superseded by the BKR7EIX but are the same. Just bought them, not really thinking.

However, it says PLATINUM on the box. Not... iridium. F*cks sake. Should I be taking them back or will they work?!

I would not fit them personally, The EVX was discontinued quite a few Years back! They will probably be OK as they are the same fitment but....

[AJP]

I'm taking them back right now

[bonelorry]

I'm taking them back right now

Ideally NGK BKR7EIX which are the Iridium's OR NGK PFR7S8EG which is the correct OEM Platinum plug that you would buy from TPS etc 

Just so you have a choice.

[AJP]

Sorted. He's ordered some BKR7EIX in for me to collect later this afternoon.

Fingers crossed I make some sort of progress tomorrow.

[fab5freddy]

No. Just throw them in. 

Ta mate. I've got a feeling new plugs will cure the symptom rather than the cause, but we'll see!

This is exactly what happened to me @AJP I changed the plugs on cylinder 3 twice and cured my symptoms, 2 weeks driving, all fine and then the misfires were back.

Not to be alarmist, but ultimately I believe it was what caused the death of my engine and why I now I run a CDL. Pistons ring had melted, which I think is down to the dodgy injector

Just be careful you don't fall into the same trap, thinking it's all sorted and behind the scenes your causing unknown damage

[AJP]

No. Just throw them in. 

Ta mate. I've got a feeling new plugs will cure the symptom rather than the cause, but we'll see!

This is exactly what happened to me @AJP I changed the plugs on cylinder 3 twice and cured my symptoms, 2 weeks driving, all fine and then the misfires were back.

Not to be alarmist, but ultimately I believe it was what caused the death of my engine and why I now I run a CDL. Pistons ring had melted, which I think is down to the dodgy injector

Just be careful you don't fall into the same trap, thinking it's all sorted and behind the scenes your causing unknown damage

I'm definitely going to get it properly checked at Statller's as soon as I can get it in, regardless of what I find with the condition of the existing plugs and how it runs with new plugs.

Strangely it ran really nicely for a day when I put the new R8 coils in. Then of course it misfired again.

So the process of pulling the old coils and fitting the new ones 'fixed' it temporarily. Now I'm asking myself if something is killing my coilpack(s). Can a bad plug kill a coil?

Or, like you say, there's more going on. I know the valve cover is a bit leaky, and as you can see in the photo in the other thread there's a bit of oil on the bolt near cylinder 2. But is it feasible that enough oil is getting down there to foul things?

I'm not ruling out an injector. Did you say your failed injector drenched the plug in fuel?

[fab5freddy]

Yes, i was "curing" the problem for a short space of time, then it was back. In a four week period, before taking it to my trusted specialist, he straight away said injector 

For me i had just done the Ko4 conversion 6 weeks previously and the S3 injectors i had fitted were brand new, it didn't even cross my mind at that stage it was an injector at fault.

It could very well be feasible, only closer inspection will tell i suppose.

Yes, the last time i pulled the plug before taking it in to the garage, it was soaked in fuel, i don't remember it being that bad the couple of times previously, again hindsight shows the injectors was probably getting worse?

Only sharing my experience and you'd be well advised to keep an open mind as with these things it could be any number of different issues, hope you get to the bottom of it soon dude 

[AJP]

Yes, i was "curing" the problem for a short space of time, then it was back. In a four week period, before taking it to my trusted specialist, he straight away said injector 

For me i had just done the Ko4 conversion 6 weeks previously and the S3 injectors i had fitted were brand new, it didn't even cross my mind at that stage it was an injector at fault.

It could very well be feasible, only closer inspection will tell i suppose.

Yes, the last time i pulled the plug before taking it in to the garage, it was soaked in fuel, i don't remember it being that bad the couple of times previously, again hindsight shows the injectors was probably getting worse?

Only sharing my experience and you'd be well advised to keep an open mind as with these things it could be any number of different issues, hope you get to the bottom of it soon dude 

That must have been gutting, straight after doing the k04 conversion. And with brand new injectors?! Wow. I did read in an unrelated thread that k04 injectors are less reliable than k03 injectors, but you wouldn't expect them to be unreliable in any way if they're brand new.

I don't know if the fact I had cyl 4 injector replaced a few weeks ago has any bearing on this. It shouldn't, logically, but you never know. Thinking laterally, if something caused the cyl 4 injector to fail, could the same thing have caused this cyl 2 injector to fail.

Funny that on the TFSI it's always the coil packs that get the blame when it comes to misfires, but if you scratch the surface you can find quite a few of us who have had injector faults.

I'll be over the moon if the misfire moves when I swap the plugs over. Let's see what tomorrow brings!

[AJP]

Little update.

Just been for a fair drive, maybe a couple of hours (yes, I probably shouldn't be driving it, but I've got things that need doing) and as expected, it misfired, struggled to get above 2500rpm etc. I can 'nanny' it, and still cruise along at 50-60mph.

But then something strange happened after about 60-70 mins driving... The misfire went away. Completely. Full power restored. I then gave it full beans and I couldn't induce one misfire.

Why would this happen?

I'll be doing the plugs in an hour or so.

[fab5freddy]

Bloody cars ehh 

Mine did the same, toddle around fine, push the loud pedal a bit to far and it misfired. I'm sure if it is the injector this will probably be an intermittent fault, hence the running ok for a time?

Looks more and more like the injector for me, hopefully someone else might have a theory...
I don't want to railroad the thinking on this...