Are these ignition coils ready to be swapped?
Discussion
From a Toyota 2zz engine, I took my plugs out for a quick inspection before my last trackday and found the coils covered in a red/brown dust (not quite rust, but looked similar) and after giving them a thorough clean I could see evidence of burn/scorch marks on the outside of the insulated section.
I didn't take a picture, but found very similar ones on google:
I cleaned them off, coated in dielectric grease and then got on with my trackday. Afterwards I checked them again, evidence that the dust has returned (though now mulched in with the grease) and you can see the burn marks too:
Car is running 'fine', always has. I've been chasing imaginary(?) performance dips which are almost certainly probably not there. Sometimes the car feels ballistic fast, others it seems just "kinda fast" - so as part of my winter maintenance I'm considering swapping these coils to rule them out.
Car has never had a problem starting, idling or running in general though - which makes me thing I'd be throwing money away but I don't know what symptoms to expect from a failing coil, all I can see online are issues with fault codes and misfires neither of which are happening to me.
I didn't take a picture, but found very similar ones on google:
I cleaned them off, coated in dielectric grease and then got on with my trackday. Afterwards I checked them again, evidence that the dust has returned (though now mulched in with the grease) and you can see the burn marks too:
Car is running 'fine', always has. I've been chasing imaginary(?) performance dips which are almost certainly probably not there. Sometimes the car feels ballistic fast, others it seems just "kinda fast" - so as part of my winter maintenance I'm considering swapping these coils to rule them out.
Car has never had a problem starting, idling or running in general though - which makes me thing I'd be throwing money away but I don't know what symptoms to expect from a failing coil, all I can see online are issues with fault codes and misfires neither of which are happening to me.
I am normally one who raves about if it aint broke, but..
This is very similar marking to those recently seen on my Focus plugs - I was getting intermittent hesitation - normally at low-ish revs - but nothing else I could pin down. It could be raining, dry, foot flat or just cruising. Late one night I had enough, pulled the plugs, and they had that grey traking on the ceramic. Late night, halfords, set of fancy plugs (all they had) and the hesitation was gone.
I would either try polish out those marks, clean them up and check it does not come back - or preferably change them.
This is very similar marking to those recently seen on my Focus plugs - I was getting intermittent hesitation - normally at low-ish revs - but nothing else I could pin down. It could be raining, dry, foot flat or just cruising. Late one night I had enough, pulled the plugs, and they had that grey traking on the ceramic. Late night, halfords, set of fancy plugs (all they had) and the hesitation was gone.
I would either try polish out those marks, clean them up and check it does not come back - or preferably change them.
Peanut Gallery said:
I am normally one who raves about if it aint broke, but..
This is very similar marking to those recently seen on my Focus plugs - I was getting intermittent hesitation - normally at low-ish revs - but nothing else I could pin down. It could be raining, dry, foot flat or just cruising. Late one night I had enough, pulled the plugs, and they had that grey traking on the ceramic. Late night, halfords, set of fancy plugs (all they had) and the hesitation was gone.
I would either try polish out those marks, clean them up and check it does not come back - or preferably change them.
Cheers, my car has always had a bit of hesitation at idle/very low revs but I've always put this down to the bigger injectors it has fitted. It's fairly similar to previous cars I've run with larger-than-oem injectors but as it's not noticeable once moving, it doesn't warrant any further thought. I guess there's an outside chance I've got some arcing at the plugs/coils which may be contributing too.This is very similar marking to those recently seen on my Focus plugs - I was getting intermittent hesitation - normally at low-ish revs - but nothing else I could pin down. It could be raining, dry, foot flat or just cruising. Late one night I had enough, pulled the plugs, and they had that grey traking on the ceramic. Late night, halfords, set of fancy plugs (all they had) and the hesitation was gone.
I would either try polish out those marks, clean them up and check it does not come back - or preferably change them.
Car will be going off the road for most of winter at the end of October so I'll have plenty of time to mull this over. At the very least the plugs will be getting swapped just as part of routine maintenance so I'll give everything a good inspection and make a decision. I do welcome any other thoughts on my pictures though.
My thoughts are still that it may be just cosmetic damage, but there must be some unintended conduction going on somewhere to cause it? That unintended conduction means my spark is (in theory) not as strong as it could be. If I was having proper running problems I wouldn't hesitate to throw some new coils in, the fact the car is running fine is what made me throw it onto PH for discussion.
tapkaJohnD said:
Fonzy,
OMG! that red stuff is a terrible scourge on all except a very few cars,, not excepting your Toyota! It's called "rust"
J.
The rust-dust I'm not too concerned about, it's more the burn/score marks on the exterior. It suggests to me that it's not insulating properly anymore.OMG! that red stuff is a terrible scourge on all except a very few cars,, not excepting your Toyota! It's called "rust"
J.
I'm sure the rust-dust is a byproduct of that, as I completely cleaned the coils the night before a trackday, did about 200miles on the trackday then inspected them again once home, the dust was back again.
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