Spark Plug Gaps
Discussion
Right, So recently I've been getting more and more into properly maintaining my own car. In the past I haven't bothered and Its lead to some very expensive MOT invoices for repairs I could have prevented for much much cheaper.
My next venture is to change my spark plugs. I'm more than capable of doing so myself, and being an engineer I have all the necessary tools. The only thing I'm struggling with is knowing the correct gap for my spark plugs. Do they come pre-gapped? is that the right gap?
I know it all sound stupid but its the first time ive done this.
I drive a Mazda 2 Colour edition 2014
Where would I find the info I need?
Thanks in advance
My next venture is to change my spark plugs. I'm more than capable of doing so myself, and being an engineer I have all the necessary tools. The only thing I'm struggling with is knowing the correct gap for my spark plugs. Do they come pre-gapped? is that the right gap?
I know it all sound stupid but its the first time ive done this.
I drive a Mazda 2 Colour edition 2014
Where would I find the info I need?
Thanks in advance
jcmcd98 said:
Where would I find the info I need?
Probably by being even mildly proactive on Google.https://www.go-parts.com/ps/products/Mazda-2-Spark...
Further to the above ^^
Buy a set of feeler gauges (although as as Engineer I'd imagine you have a set?).
Buy a set of plugs.
Use feeler gauges to measure the gap. Gently tap the electrode of the plug to narrow the gap, prise it up (gently) with a suitable tool to increase the gap.
You’ll find that most plugs come pre-set (‘pre-gapped’ if you will) these days, so you probably don't need to bother with setting the gap. And do not try setting the gap on multi electrode plugs.
Fun fact: the cardboard from a pack of fags is aprox the right gap for older engines. Also works for setting the points gap on an older car.
Buy a set of feeler gauges (although as as Engineer I'd imagine you have a set?).
Buy a set of plugs.
Use feeler gauges to measure the gap. Gently tap the electrode of the plug to narrow the gap, prise it up (gently) with a suitable tool to increase the gap.
You’ll find that most plugs come pre-set (‘pre-gapped’ if you will) these days, so you probably don't need to bother with setting the gap. And do not try setting the gap on multi electrode plugs.
Fun fact: the cardboard from a pack of fags is aprox the right gap for older engines. Also works for setting the points gap on an older car.
You cant beat a bit of old plug maintenance, get yourself a plug electrode file to file the electode so it has a nice flat surface and sharp edges for the now nice big fat spark to jump, small wire brush to clean all the crap and carbon off , nice clean lint free rag to clean everything off and a set of feelers to re-set the gap, clean the porcelain then ensure the connector on the top threads (if fitted) is nice and tight and replace the plug into the head, onto the next one.
Save yourself some beer tickets.
Save yourself some beer tickets.
phumy said:
You cant beat a bit of old plug maintenance, get yourself a plug electrode file to file the electode so it has a nice flat surface and sharp edges for the now nice big fat spark to jump, small wire brush to clean all the crap and carbon off , nice clean lint free rag to clean everything off and a set of feelers to re-set the gap, clean the porcelain then ensure the connector on the top threads (if fitted) is nice and tight and replace the plug into the head, onto the next one.
Save yourself some beer tickets.
When was the last time you had an ignition fault or issue that was solved by cleaning the plugs? When was the last time you had a spark plug that was the fault? How much is a set of plugs, versus your time , if you suspect such issues?Save yourself some beer tickets.
And if you must brush them clean, use a brass brush, not a wire brush.
Always check the gap. Eliminates any chance that the plug has been dropped & closed the gap.
There was a programme some years ago - a competition for young mechanics.
Fitting new spark plugs was part of the exercise & the examiners had closed the gap on one of them for each candidate.
IIRC at least two didn't bother checking & consequently spent considerable time trying to find the misfire.
There was a programme some years ago - a competition for young mechanics.
Fitting new spark plugs was part of the exercise & the examiners had closed the gap on one of them for each candidate.
IIRC at least two didn't bother checking & consequently spent considerable time trying to find the misfire.
Coilspring said:
phumy said:
You cant beat a bit of old plug maintenance, get yourself a plug electrode file to file the electode so it has a nice flat surface and sharp edges for the now nice big fat spark to jump, small wire brush to clean all the crap and carbon off , nice clean lint free rag to clean everything off and a set of feelers to re-set the gap, clean the porcelain then ensure the connector on the top threads (if fitted) is nice and tight and replace the plug into the head, onto the next one.
Save yourself some beer tickets.
When was the last time you had an ignition fault or issue that was solved by cleaning the plugs? When was the last time you had a spark plug that was the fault? How much is a set of plugs, versus your time , if you suspect such issues?Save yourself some beer tickets.
And if you must brush them clean, use a brass brush, not a wire brush.
phumy said:
I never mentioned anything about ignition issues, i just mentioned that it was good to do some plug maintenance. I only maintain my cars when i am on leave or at weekends so it costs me no time at all and i love doing it so theres the trade off. I have never had an issue with plugs for about 40 years so im probably doing something right...
Fair comment.I have never done any such "maintenance", but service vehicles daily. Always change plugs at the recommended intervals, and never had any plug related issues either. So I am probably doing something right too.
I doubt you are achieving anything, and more likely to cause issues than cure anything (if there is no issue it is like trying to fix something that isn't broken). But if you have the time, and it suits you, then go for it. No vehicle manufacturer that I am aware of suggests such action is necessary or part of any service schedule, even with long life plugs.
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