Sparkplug check

[Tom777]

So the IS250 has spark plug change interval at 60.000 miles. I’m 6000 miles away from my next one. Does anyone know if it’s worth pulling just one of the easy accessible plugs and check it’s conditions to just get an idea about all the spark plugs’ overall condition? Is it possible to judge a spark plug by looks alone so as if it looks completely clean I shouldn’t worry too much about going 10000 miles over the interval or so. I know the generic answer is why not change them as recommended interval  etc but has anyone some alternative views on this. Some places people even say it’s a bit overkill to change at 60.000 and that Lexus changed that interval back in the days because of emissions etc. so in theory the spark plug could be good for another 30.000 miles. My IS250 had regular good oil changes so it’s been taken good care of in the past. Last spark plug change was at 60.000. So what about the looks of the the spark plugs. Maybe I should take one out and share a picture here. My engine is running very well - I’m actually worried about that it doesn’t eat any oil at all as it’s supposed to😂

[J Henderson]

If the engine is running fine, don't worry about it.

I had mine replaced at 64K when the car was 9 years old. Car was running fine, but just wanted them changed for piece of mind.

Mechanic told me afterwards that they would've been good up to 100K.

 

[Tom777]

50 minutes ago, J Henderson said:

If the engine is running fine, don't worry about it.

I had mine replaced at 64K when the car was 9 years old. Car was running fine, but just wanted them changed for piece of mind.

Mechanic told me afterwards that they would've been good up to 100K.

 

👍🏻

[Spock66]

How long do you plan to keep the car?

If you just delay changing the plugs a year or so you are not really saving any money, only deferring the cost.

On previous cars I have found that a new set of plugs certainly helps with fuel economy.

[Tom777]

I planning on keeping the car for the rest of my days if possible. My fuel economy is great. I think I will leave them in for another 20.000 miles, and just do the good oil change for now. There are other change intervals that  might be more pressing than spark plug change - like changing diff oil, and top up / exchange transmission oil. I wouldnt hesitate to change spark plugs if it was just a quick job but as we IS250 owners know it’s a little bit of work/money to change these spark plugs. Just check Scotty. He knows what he is talking about. 

 

[Mr Vlad]

You say the spark plugs were changed on your car at 60k miles. How many miles on your car now?

[Tom777]

114.000

[Malc]

Tom hi ....  I'm thinking that if you're quite able to do the spark plug change yourself then it's maybe a little tight fisted not to pay out a relatively small amount to buy a set of good quality plugs ............. plug changes can be  effective preventative maintenance   too and help you not to have issues later on in the life of your car ......  which you're intending to keep forever you say 

Malc

[Texas]

So yes, according to the schedule they will be due at 120k miles, but they can, and do last a lot longer before replacement is actually required, The intervals in the schedule are so to keep the emissions to a minimum.

[Tom777]

Yes the emissions seems to be a big deal for Lexus. But not for. I think I will leave them in for another 10.000 miles. Shouldn’t do any harm, and give me 2 years more before actually having to change them with my low mileage driving 

[Beamish]

 

It might be no harm to pull one of the easily accessable plugs just to check that the correct plugs were fitted and get an idea of the overall condition.

Dec.

[Tom777]

That’s where I’m a little bit concerned as pulling out an old plug and then put back in. Do you know if I should make sure to add copper grease to the plug when reinstalling. I know that the correct plugs are installed  from the service history so no worries there. Another thought is to actually just change the 3 plugs that are easy accessible if I’m having a go at it anyway. They are cheap,  and I guess having 3 new plugs in there will do no harm.  

[Beamish]

 

If you are happy that the correct plugs are installed I would be inclined to leave well alone.

I would replace all the plugs at the same time if and when you decide to tackle the job. It is time consuming but not hugely difficult if you allow yourself plenty of time.

The new plugs should be fitted dry, the use of copper grease is not recommended. The torque setting is, from memory, 25Nm.

The original plugs fitted were Denso FK20HBR11 iridium but they are not cheap  -  you should probably budget for £80-£100 for a full set of six.

Denso also now offer a cheaper TT plug for this engine but I do not have the reference.

Be very carefull where you source replacement sparkplugs as the internet is awash with counterfit items.

Dec.

[Tom777]

1 hour ago, Beamish said:

 

If you are happy that the correct plugs are installed I would be inclined to leave well alone.

I would replace all the plugs at the same time if and when you decide to tackle the job. It is time consuming but not hugely difficult if you allow yourself plenty of time.

The new plugs should be fitted dry, the use of copper grease is not recommended. The torque setting is, from memory, 25Nm.

The original plugs fitted were Denso FK20HBR11 Iridium but they are not cheap  -  you should probably budget for £80-£100 for a full set of six.

Denso also now offer a cheaper TT plug for this engine but I do not have the reference.

Be very carefull where you source replacement sparkplugs as the internet is awash with counterfit items.

Dec.

Nice one Dec. Thanks for providing the torque setting also as its these kind of things that worry me when it comes to breaking things. I will get the original plugs from Lexusparts direct to be on the safe side, and yes if one gives oneself a lot of time it should be doable. Just worried that I could break something when taking things apart but it will hugely satisfying to do it myself obviously. Also I would add a new gasket if I was to go ahead with all 6, and a new washer for fuel line. Thanks 

[Beamish]

 

The fuel line as featured on some of the US You Tube videos is not fitted to our cars so that is one thing less to worry about.

Dec.

[Tom777]

4 minutes ago, Beamish said:

 

The fuel line as featured on some of the US You Tube videos is not fitted to our cars so that is one thing less to worry about.

Dec.

Aha, that’s good to know. I need to have a look at that

[Mr Vlad]

Sorry but the fuel line IS attached to the inlet manifold. I undid mine when I attempted to replace the crankcase breather valve. Unfortunately the pipe to it was as tight as a tight thing and I couldn't get it off.

[Beamish]

 

I find that very strange Vlad.

I have replaced the plugs on my previous 2006 IS250 and my current 2009 car and neither had the fuel line going to the plenum chamber,  or surge tank as Lexus refer to it.

John's excellent tutorial here:  

 

also shows the surge tank without the fuel line fitted.

I guess we'll just have to wait and see what Tom comes back with.

Dec.

 

[Tom777]

This is the guide I would go by as it’s the most detailed one I have found, but maybe this is an American dude doing this on an American car: 

 

 

 

[Tom777]

11 minutes ago, Tom777 said:

This is the guide I would go by as it’s the most detailed one I have found, but maybe this is an American dude doing this on an American car: 

 

 

 

At duration 31.55 into video. Is this only applicable to American model. I don’t think so. That would be surprising. The fuel line must attach the same way to UK models, right. Anyway we can just go and have a look at our engines obviously - being careful not to break any of the engine covers 😂

[Beamish]

 

Here's another one for you.

RHD car so should be similar to ours.

The video is fairly drawn out but if you go to roughly 7.30 minutes in you can see clearly that there is no fuel line attached.

I beleive the fuel line on the US models is attached to some sort of cold start valve which does not feature on our cars.

No need to remove any engine covers to check.

Dec.

 

[Tom777]

What video. You mean the one I shared? Or did you forget to share the video you are referring to

[Tom777]

12 minutes ago, Tom777 said:

What video. You mean the one I shared? Or did you forget to share the video you are referring to

Ok this is getting confusing. And here I thought I found a good video to follow but actually it seems to be a different setup compared to my engine. No fuel on mine etc and loads of bits and bobs that need to be dismantled not d in the American version. Im glad I’m starting to think about this now as I now have to think about it all over again and where to find a detailed guide on the change. 

[Beamish]

Apologies.  Video here:

 

 

[Tom777]

15 minutes ago, Beamish said:

Apologies.  Video here:

 

 

Yes that’s a great video too. That’s my engine. You learn something new every day. But my it’s shocking how difficult Lexus made it to change 6 spark plugs. It’s not impossible but still it’s fiddly like hell, like needing magnets and stuff. But this is really good video to have at least to remind me also how to put things back together.