Burnt Spark Plugs! Why?

[JaseYpk]

Ok I pulled my spark plugs out the other day to find that they were disgusting, and one was beyond working order.. so they've now been replaced by "NGK Platinum Spark Plugs" (anybody got an opinion on these? they were the only ones i could find at the time that would fit).

Anyways, heres what the old ones looked like, and i'm curious whats causing them to look so nasty, and what the burning looking mark is around the base of the ceramic section?

The blackened electrode area (according to various websites) is probably overfuelling, but i cant find any info about the actual ceramic bit itself?
Also notice the side electrode on the first spark plug - its only half there! bad times!

Any ideas?

cheers

 

[AllanOrr]

hmm the over fuelling would make scence to be honest though personally I didnt think it would do that much damage

 

[Toby]

Thats got very hot to totaly brake the electrode off, what fuel do you run the car on, and what boost do you run?

 

[Auss15]

I'd say its more due to running too lean,thats what generates the heat.Check your AFR's, maybe throw in a cooler plug (7)

 

[AllanOrr]

would that be (could be wrong with what its called) DET? when the car runs to lean?

 

[Toby]

Yes, but running lean is running lean, Dettonation is a by product of running too much boost without supported fueling (normally)

For example, if the engine these plugs were in was running anything over .8bar and doesn't have a walbro fitted this is highly likely to happen.

Fuel can be a factor too - Even a std engine could have detonation if they don't run 97+ RON.

 

[Darren_S15]

Yeah I was going to say running lean to get that hot.

The end of the plug should be a nice coffee colour if its running correct.

Assume the first plug on the left got snapped after it came out the car?

 

[craig8585]

Det is the product of running very lean. You can run lean without detination but they look fairly bad mate. Time for a remap

 

[andeep]

Have you upped the boost at all? If you have you really need colder plugs.

 

[JaseYpk]

i always run V-power from Shell, which i believe is 99RON, unless that garage is closed or empty, in which case, tesco's 99RON, however once this year i had to put 97 RON in from motorway services.. think it was ESSO.. or i'd have run out of fuel mid drive lol.

boost is just the standard, never goes over 0.6 / 0.7
could this have anything to do with my exhaust going bang on a regular basis? do you reckon my cat would be nackered?

 

[JaseYpk]

Yeah I was going to say running lean to get that hot.

The end of the plug should be a nice coffee colour if its running correct.

Assume the first plug on the left got snapped after it came out the car?

the first plug was already snapped when it came out...

 

[andeep]

the first plug was already snapped when it came out...

That's not a good sign mate

 

[Toby]

So its not fuel, and its unlikely to be leaning out causing the heat.

Do you have a fmic? do you have temp gauges, if so what do they read?

Was it the front cylinder that the broken spark came out of?

I would do a compression test before you spend any money on anything other than a new set of plugs.

Buy NGK BCPR7ES

 

[JaseYpk]

So its not fuel, and its unlikely to be leaning out causing the heat.

Do you have a fmic? do you have temp gauges, if so what do they read?

Was it the front cylinder that the broken spark came out of?

I would do a compression test before you spend any money on anything other than a new set of plugs.

Buy NGK BCPR7ES

No FMIC, just standard WMIC, no gauges either.

yes, it was the front cylinder that the nackered plug came out... what made you suggest that?
where, why and how much will it cost for a compression test?

note - my exhaust is VERY black and is banging on the majority of gear changes..

also, whats the difference to the spark plugs you recommended and the NGK platinums i've got fitted?

 

[y2kfarrell]

compression tester is about 40pound
http://cgi.ebay.com/Sykes-Pickavant...160437328806?pt=UK_Diagnostic_Tools_Equipment (just an example for ya)
Any garage worth its salt will have one, and test will cost about 50quid.
had the same hassle myself and engine was running lean, ended up blacking the plug, well was only one plug at the black of the engine.
cause of this it caused a build up of sutt on the valves, engine had to be stripped and valves cleaned my compression was down to 95 on the back and 120 on the rest (could be wrong but correct compression out of the factory is 155 but if you have a standard 135 upwards all cyclinders reading the same your safe enough no danage done) "Someone correct me if im wrong".
Not the biggest of jobs but needs sorting fast.
that orange colour ive seen before once or twice and it was cause of old age, seen it on a civic and a corrolla.

 

[JaseYpk]

ok sound mate cheers. i've got next week off so i'l get it down the garage and get that sorted out

 

[andeep]

The major problem here is that the spark plug tip has come off and is somewhere in the engine. If it's been bouncing around ontop of the cylinder it can cause damage. Have you found the tip?

 

[JaseYpk]

oh.. never thought of that. i just assumed it'd disolved somewhere or something.. the problem also is i have no idea how long its been like that! would this mean i need to take the head of the engine off to have a look for it?!

 

[andeep]

It would have snapped off and bounced about in on top of the piston. You need to get this out before it can do anymore damage, so don't start the engine until you get it out.

Hopefully someone can advise more about this, but it's a very serious issue mate. I would recommend taking the head off and inspecting if there's damage as there is bound to be some, then you can see what to do after that.

You also need to see why the tip broke off, which was probably down to DET, this is most probably down to fueling and the engines timing.

Put up a post on SXOC about the plugs and about the tip thats broken off.

Hope you get it sorted mate!

 

[JaseYpk]

ok cheers mate, how easy is it to just unbolt the head, have a quick look, and pop it back on? as i've got a 300mile drive tomoro, and again on tuesday and wed... all 3 of which HAVE to be done.