How will i know if i need to change spark plugs?

are there any tell tale signs they need changingHow will i know if i need to change spark plugs?
usually at this time of year,cars start getting damp,a common problem is your spark plug leads,if you start up your car with the bonnet up,look at the plug leads and look for any stray sparks,if they are sparking,use wd40 and spray onto leads around the distributor cap,all lead connections etc.Once you have done this,you will probably get smoke coming from the engine,but dont be concerned at this,its only vapour burning off with the heat from engine,then take your car for a spin.If still the same,go to halfords and ask them for spark plugs to suit your vehicle,they are very easy to change out,remove only one plug lead at a time,so you dont get confused,take your plug key and remove the old plug,install the new one,but do not overtighten,and replace the plug lead,just work from one end to the other until you have changed all four,then off you go!!No rocket science here,you can save yourself around 50 quid doing them yourself,good luck!How will i know if i need to change spark plugs?
They should be changed as a matter of course during a service
If you don't know the answer to this question, do not do them your self, as a long time mechanic Ive been repairing peoples mistakes for a long time, have a friend who knows what he is doing look at them



people believe there car will run so much better with new plugs, and generally this is not the case



newer cars have high quality plugs that can go much longer then years ago
If you have a service book with your vehicle, check to see when it was last serviced. Usually they are changed every time you have a full service, most people have their vehicles serviced every 12 monthes unless you do a lot of mileage then some people have a service every 6 months, or so. Unless there is a problem with the vehicle such as damaged or corroded plugs.
since they are so low cost just change then every 50,000 miles. but if you want to get into reading them for performance get a good chart light brown on the end is good black is too cold/rich white is too hot/lean white can also indicate coolant leaking into your heads.
your car will start to miss you will use more petrol you should change them when you have a service
Depending on your car and whether there is a problem.

Most modern cars (last 5 to 10 years) have spark plugs designed to last 100,000 miles, so you need to know the car manufacturers recommendations.

If the car is miss-firing then they would be checked as part of the elimination process.
your car will run poor or it will missfire.
if the vehicle is down on power or the fuel economy has declined, then you should have a technician pull one plug and inspect it. That's usually how we determine if they need to be changed. Either that or as a matter of due course, every 75,000 miles.
... ummm... if your car has difficulty starting up, runs sluggishly, or doesn't even start at all!!



They should be checked and changed as a matter of course when you take your car in for a service.
If your vehicle is running ruff than it may be a bad spark plug. If you have a car that was manufactured after 1980 spark plugs are usually Platinum and don't need to be changed for 100K miles. As a Mechanic the spark plugs are usually the last thing I check. There are many other problems that would make you think it is the plugs but it isn't. You should have a mechanic look at the vehicle to determine what needs to be address. You may or may not be able to make the repairs to the vehicle your self but at least you will know what is wrong with it. Look to the fuel injection, fuel pump, clogged filters first...Enjoy the ride!
normally spark plugs can be cleaned up and adjusted ,but if you look and find the electrode is broken or worn you have to change them
Take plug out clean with wire brush check gap with feeler Gage's look in manual for plug gap size,do one by one putting leads back when doing one by one,don't mix leads up,Impotent.if plugs look shot buy new
generally all the car maunfacturers recommend through a chart to change the plugs and filter etc,



but if your car has a delayed start than normal it is first symptom other than that it is advisable to change when you feel the car gives a missing signal subsequently developed in to rocking the engine.