Spark Plug Replacement

[svf]

How often should we change spark plugs

Is there an optimum amount of tightning when fixing spark plugs

[MrCat]

Well it really depends on the car and engine. I would refer to a user manual for the specific model to find out. User manual (or better if you can find a service manual) specify the torque values to tighten plugs.

If it`s not possible to measure exact toque, I would tighten till the washer seats well with the engine block and then tighten another 1/2 turn. Usually spark plugs comes with a aluminum washer that gets squashed flat (the first time you use) for a perfect fit.

[Muditha420]

it depends on plugs you have i think

some require change after 15,000km those would be normal plugs others like platinum tipped once should be around 50,000km right.... anyone correct me if m wrong here

guess a good check on the plugs would show if tis time to change them or not. this is what i found on Haynes Manuals, should be useful

Examination of the spark plugs will give a

good indication of the condition of the engine.

If the insulator nose of the spark plug is clean

and white, with no deposits, this is indicative

of a weak mixture or too hot a plug (a hot plug

transfers heat away from the electrode slowly,

a cold plug transfers heat away quickly).

If the tip and insulator nose are covered

with hard black-looking deposits, then this

is indicative that the mixture is too rich.

Should the plug be black and oily, then it is

likely that the engine is fairly worn, as well as

the mixture being too rich.

If the insulator nose is covered with light tan

to greyish-brown deposits, then the mixture is

correct and it is likely that the engine is in

good condition.

[lasi]

  On 5/12/2011 at 5:43 AM, svf said:

How often should we change spark plugs

Is there an optimum amount of tightning when fixing spark plugs

usually, maximum electrode gap is 1.3mm according to manufacture's specification.

but people go beyond that. best thing is to check it twice a year. life time depends on the type of the plug. iredium tiped plugs last longer.