2009 Yaris - Spark Plug Replacement Interval

[HarrySteph]

Have had a 59 Plate Yaris 1.33VVT since new - has 26k miles on the clock. It is used as a second car mostly around town to supermarket, etc.. For the past 6-7 years it has done an average annual mileage of around 1000.

My question is .......when should the spark plugs be replaced. Service company tries it on every year - wants £180 to do it, but the car starts and runs everytime without any problem. I've Googled the question and the answers vary - some saying between 30k-60k miles!? 

Does anyone know the answer, please?

 

[FROSTYBALLS]

6 years or 60,000 miles, whichever occurs first.

The answer will also be in the service & warranty book.

[Bernard Foy]

Modern plugs can work effectively for upwards of 60,000 miles no bother. I wouldn't be changing them before 50,000 miles. But I would have a look at them around 50K.

[FROSTYBALLS]

4 minutes ago, Bernard Foy said:

Modern plugs can work effectively for upwards of 60,000 miles no bother.

Then again the car is 13/14 years old.

[Mojo1010]

Put the reg in and buy from here Car parts for less

It's not a difficult job to DIY. If not able, pay a small fee for the local mechanic to do in the future. If the car still starts fine then can just continue for a year or so longer. Plugs are cheap. 

 

[Mooly]

I would leave them based on my experience. My Auris (same engine) had them changed at 60k and it would have been 9 years old. The originals looked as new at the all important tip, still needle sharp. I was amazed how easily they came out as well, a child could have undone them with no bother.

Be aware the original plug type is discontinued by Toyota and the SC16HR11 now replaces the original SC20HR11

Given your very low mileage I would leave them.

Our old 2003 Corolla (which was my dad's) has I suspect still got the originals fitted... mileage is low for its age but twice what you have done and these are also not Iridium plugs with such a long change interval. 

[TonyHSD]

Spark plugs usually aren’t a time interval replacement parts as they don’t age like rubber or plastics. However when left for a very long time they might become very difficult to undo and cause damage to the engine head threads when undoing is attempting.  At your low miles I will just leave them. 
All that if your spark plugs are the mentioned above Iridium type . If they are standard plugs then 30k miles intervals are fine and just about for replacement. 

[HarrySteph]

Thanks, everyone, for your response.

Much appreciated! 

 

[flash22]

09 1.33 is right around the time when they changed the plug heat rating - £180 seems steep for 4 plugs that are £12 each full retail - only use Denso plugs

[scannerman]

At 100K, decided about time for a plug change, not because they were faulty but nothing lasts for ever, but they still looked good. Bought some Densos online which burnt out in about 100miles🤨, won't do that again but they were cheap. Went to my local Factors, the ones the local garages use and they came up with a set Bosch plugs, which were reasonably priced, they've been in a year, no problem.

[HarrySteph]

Thanks Bob & Noel for your advice. I think it’s safe to say that at 26k on the clock the current plugs are staying in situ!

As I suspected, the garage was simply being greedy looking to do unnecessary work!

[TonyHSD]

1 hour ago, scannerman said:

At 100K, decided about time for a plug change, not because they were faulty but nothing lasts for ever, but they still looked good. Bought some Densos online which burnt out in about 100miles🤨, won't do that again but they were cheap. Went to my local Factors, the ones the local garages use and they came up with a set Bosch plugs, which were reasonably priced, they've been in a year, no problem.

The spark plugs are the most popular fake parts in Toyota  kingdom. The Denso are also well known to be made a lots of counterparts. 
From where did you buy yours ? 
The best way to avoid spark plugs drama is to purchase from dealers that sells cars too. I do that always through eBay but only from well known dealers, or I had bought Denso from Halfords last time which so far has done 35000 miles and seem ok. 

[Stevie J]

In the olden days when cars ran with carburettors and mechanical distributors, you tended to replace the spark plugs on each major service, every 6 to 10K miles, along with the points (remember them?). Back in those days, plugs were more likely to get carbon fouled or damaged due to bad carburation or incorrect timing, so they needed checking, re-gapping or replacing much more often.

These days with modern engines that are computer controlled via ecu, with fuel injection and timed to perfection, the plugs tend to stay in good condition for as long as the engine runs correctly, only requiring attention at 60K miles - UNLESS there is a problem with the running of the engine, such as bad oil control rings on the pistons, allowing oil burning, which will foul the plugs and ruin them. The early 1.33 engines fitted to 2009 Yaris's sadly became known for premature wear to the oil control rings, and they did have issues with plug fouling and oil burning.

I would say to remove the plugs yourself if possible, and inspect them to see if they are clean and serviceable. If so, then run with them. As said previously, they dont suffer from age related failure - only needing replacement at high mileages whilst the engine runs properly with no timing, fueling, or oil burning issues.

My car still has the original plugs at 10 years old and 34K miles. I would not even entertain changing them at this mileage unless I started getting misfires and the engine management light coming on. Modern cars just dont need regular spark plug replacement like old cars from the 60s, 70's 80's and early 90s did.

[scannerman]

20 hours ago, TonyHSD said:

The spark plugs are the most popular fake parts in Toyota  kingdom. The Denso are also well known to be made a lots of counterparts. 
From where did you buy yours ? 
The best way to avoid spark plugs drama is to purchase from dealers that sells cars too. I do that always through eBay but only from well known dealers, or I had bought Denso from Halfords last time which so far has done 35000 miles and seem ok. 

eBay

[scannerman]

21 hours ago, HarrySteph said:

Thanks Bob & Noel for your advice. I think it’s safe to say that at 26k on the clock the current plugs are staying in situ!

As I suspected, the garage was simply being greedy looking to do unnecessary work!

Make sure they are Iridium plugs for your car, my 2008 Yaris uses normal plugs which are not as long lasting.