Spark Plugs - should I change them?

[matt_fsr]

The car: An old Mk2 Mondeo, with almost 150k on the clock.

The spark plugs have been in since about 110k - but there's no problems with the engine at all.

I'm being lazy here, as I haven't had them out for a visual inspection, but can anyone advise if there's a genuine benefit from replacing them, before they're knackered?

Would for instance, newer spark plugs create a bigger spark, and therefore a cleaner/more efficient petrol burn, (More MPGzzz) or is a cylinder explosion a cylinder explosion?

Hoping someone with a bit better knowledge of I/C engines can advise

 

[Firestar_3x]

What type of plugs are in?

Worst case is the tips could fail and drop into the bore, for the sake of £10 or whatever i'd change them.

 

[Jonny69]

Take them out and check them. No problems, no replacey.

 

[Matt82]

what firestar said. nothing to gain by leaving them

 

[Dogbreath]

Would for instance, newer spark plugs create a bigger spark, and therefore a cleaner/more efficient petrol burn, (More MPGzzz) or is a cylinder explosion a cylinder explosion?

A very worn plug, or one with significant deposits built up on it can cause misfiring, which may be very subtle.

 

[Tesla]

I just this week serviced my old Mk2 Mondeo with almost 170k.

5L 5W30, oil filter, air filter, fuel filter and 4 x spark plugs set me back a grand total of £34. Seemed mad not to do the lot.

Got the oil from Ford parts counter, £16.16.
Got the rest from eurocarparts with the "winter25" code at £18. Fuel filter was £5 and arguably could be skipped over.

 

[Rich_L]

Take them out and check them. No problems, no replacey.

Tbf the parts are so cheap that if you're going to do all the hassle to check them you might as well just put new ones in

 

[andy_mk3]

If they're the Iridium plugs then they're good for 50k, standard plugs then they're well due a change. New plugs will have less resistance so a stronger spark

 

[Matt82]

I had the 30k mile old platinum plugs out my golf the other day. Gap was barely more that the 0.8mm they had when new

 

[Brookert]

If it costs a few quid why not? If your unsure about a cars history, best thing to do is give it a good service.

Got my car at 36,000 miles, but about 8 years old at the time. Had no idea about service history, so it had plugs, oil fuel air filter and oil change. cambelt and tensioners and coolant changed too.

Then you know exactly the condition it is now in

 

[OpenToSuggestions]

Just change the sparks. If you take the old ones out to check them then you have done 99% of the work as you need to then put them back in.

A set of 4 sparks shouldn't even be £15 .

 

[andy_mk3]

Just had a look on autodata and they are platinum plugs (for a 2.0 at least), and the plugs should be changed every 40k miles or 2 years.