Melted spark plug!! Causes?

[JamesBryan]

EFI could probably map it.

 

[R3k1355]

You'd want to ask for a more conservative map with an emphasis on det control.

Often with a Turbo'd motor you'd knock the boost down a couple of Psi on a full day track session to help keep intake temps down and give yourself abit of a safety net.
Obviously on a supercharged engine thats not so easy and intake temps can get mental if unchecked, they're going to be naturally higher if you're overdriving the charger for more boost too.
Having the IC top mounted can give issues with heat soaking as well.

 

[Dan@SJM]

Get it remapped on 95, then run 98/99.

 

[GrahamS]

This is what I was talking about on Saturday Dave. Not sure whether mini factory ECUs have this functionality built in but may be worth a bit of research. It definitely was an interesting watch none the less.

 

[Scrooge]

I've seen this happen on a cooper s with a slight boost leak aswell

Manifold was also glowing too.

Most likely a bad map though

 

[Sir_Dave]

The fuel filter on the R53 is supposedly a lifetime jobbie, but some people have seen them be pretty nasty if they've not been changed.
If the fuel at the track had sat around for a while it can loose some of it's fizz, but it does take a little while, how many track days is the place running over winter anyway?

I think Richard changed it before, but ill do it again, is pretty much the only thing i havent changed on it so far lol.
Fuel wise, not sure how many other days they will have done, ive asked them to dip the tank, but i doubt they will ...

I bet the map is only a tiny bit out. Ignore you did 150 miles on track before it popped. It'll have been going a tiny bit ever since it was fixed. Its eating spark plugs FFS. Something is very wrong, not that its gone hard on 95 for an hour.

But the plugs were perfectly fine prior to the trackday (i checked them the weekend before), & id done 1500 miles & 3 track days since they were last changed, which would suggest that the map is fine? Im not a numpty lol, i do a million pre-trackday checks on the car, in the previous 2 weeks id bled the clutch/brakes with new fluid, checked the sparks, assessed the brakes/cv joints/bushes, did an engine/gearbox oil service, etc etc, all was spot on, no issues to report.

The first plug went in 5 mins after the "super" was put in it, the 2nd plug went 5 minutes after all 4 old ones were swopped with new. So i think it was bad fuel, but with me not being 100% mechanical, i like to get the opinions of others.

Obviously on a supercharged engine thats not so easy and intake temps can get mental if unchecked, they're going to be naturally higher if you're overdriving the charger for more boost too.
Having the IC top mounted can give issues with heat soaking as well.

Yeah, temps were getting on a bit, but only up to circa 50IAT, the GRS has a pretty good recovery rate, & i hadnt experienced any boost clipping at all in the morning. If IATs go above 50 i tend to let the car cool off a little before giving it the beans again.

This is what I was talking about on Saturday Dave. Not sure whether mini factory ECUs have this functionality built in but may be worth a bit of research. It definitely was an interesting watch none the less.

Ah cheers, ill have a look at that at lunchtime!!

Re: getting it mapped on 95, i never even thought of that!! I guess i always aim to put 98+ in it, would make some sense though i guess, especially if the car is potentially so sensitive to fuel quality on track.

 

[Waitey]

It won't be fuel. Other wise stuff would be popping all over track if a mini with 134bhp/litre was killing its self.

There is something odd with your engine, its under power, eats plugs, and on a 98 only map. It doesn't add up.

You do variable analysis! You don't have enough constants for it to be fuel alone.

 

[Sir_Dave]

My analysis says i should have just kept the GP and not bought this off Rich 😂

 

[GrahamS]

This just popped up on my feed too. Damn mighty car mods making me crave haltech http://www.haltech.com/knock-control/

 

[Saner]

This just popped up on my feed too. Damn mighty car mods making me crave haltech http://www.haltech.com/knock-control/

You posted that video, in this thread, yesterday.

Dejavo?

 

[flebay]

You posted that video, in this thread, yesterday.

Dejavo?

Alzheimer is a cruel mistress.

 

[GrahamS]

You posted that video, in this thread, yesterday.

Dejavo?

I posted a link to the vid but not the textual explanation behind it all

 

[R3k1355]

It'd be surprising if the current ECU didn't have some form of Knock control, it's quite a basic thing and has been around as pretty much as long as fuel injection.
An AFR gauge as mentioned before would be a good idea, and a remap to 95 ron.

Odd that it happened after the fuel went in, could be the reason could be coincidence - you're not really going to be able to figure that one out for yourself.

 

[Budgie]

I'll give you £500 for it.

 

[Scrooge]

Have you checked boost leaks Dave?

 

[R3k1355]

Boost leaks would usually over-fuel though, not blow the end off the plug.

 

[Scrooge]

Boost leaks would usually over-fuel though, not blow the end off the plug.

Indeed but I've seen an MCS do it and for something quick and easy to check it's worth the look

 

[TheEvilGiraffe]

I'll give you £500 for it.

Wow, didn't realise spark plugs were so valuable on the second hand market !

 

[Dan@SJM]

Mapped on 95 is a good safe guard. I shall be doing it with Tcup if I can. But I don't know how liable it will be to knock when I'm starting to wind some proper boost into it. If I can't do it then I'll be doing 97, then running 99 with an octane booster. I always try and advise people (with highly modified cars) to run the worst fuel they are likely to for mapping then run the best they can..

 

[Sir_Dave]

Quick update on this. Bedford dipped their tank and gave me a free track day :up:
So cue 10 months of it not being used (i bought an R56 fJCW after it became apparent that the R53's valve stems needed doing), then did a trackday on 1st May at Goodwood and its now ummm, dead.
In effect, i got another PO301 Cylinder 1 misfire 30 mins or so before the end of the day, so went back to the pits, assuming it had probably done its usual trick of melting a spark plug. Unfortunately, having whipped them out, realised there was nothing wrong with them, then replaced all 4 anyway, the misfire stayed, so i had to drive the 45 miles home to Weybridge on 3.5 cylinders.
The 4 spark plus are below, Cyl 1-4 left to right:

A comp test at the weekend showed the following:

As im not exactly an engine builder, I've bought a refurbed standard head for £220, with the hope that its something simple in the head like a valve spring, but what are peoples thoughts on the likelihood of further damage, i.e. pistons etc and the rebuild starting to get beyond my capability levels? The car has used oil on cold start for a while (valve stem seals), but never when warmed up (usually rings).
For @Waitey i will be buying some Bosch 550cc injectors and getting the map redone once its all built back up again.

 

[JamesBryan]

Do the compression test wet with a bit of oil down each cylinder and see if it changes.

Probably is the valve stems though, like you say it's been like that for ages.

 

[Silent_Scone]

I would get it bore scoped, you're going to have some scoring at the very least now. At the very least compression test.

They're pretty resilient in truth, though. Mine ate chunks of chicken mesh and barely lost any compression lol

Edit: just noticed this is the Cooper S, thought it was a boosted Clio

 

[R3k1355]

The head is coming off anyway so you'll get a good look at the pistons, if you're melting plugs there will be some damage, how much is the question.
Probably worth doing this before the head comes off too \/

Do the compression test wet with a bit of oil down each cylinder and see if it changes.

Are Grade 8 plugs the recommended one for your state of tune?

 

[TimR26]

Well, at least the spark plugs are ok...

Hope you get it fixed.