Service item clarification

[rich1068]

There are some additional items in my service handbook that are separate to the Intermediate or Full services. For instance, spark plug replacement is required at 60k miles but it does not say 60k miles or (eg) 6 years. It also says timing belt at 100k miles but it does not say 100k or (eg) 10 years though it's generally agreed here and elsewhere that the 10 year interval is just as important. However, with a comparatively minor item such as the air filter the handbook is quite clear that it should be replaced every 4 years or 40k miles.

So how are we supposed to interpret these service items on vehicles like mine and others on here that haven't done 10-15k miles per year?

[Hangie]

Spark plugs should be done by millage only as they don't really degraded if not used. Of course you can have some corner cases like car haven't been used for 5 years etc but normally just change with millage.

As for belt it is a bit more complicated as rubber can go wrong just by age. It is not as bad tyres as there is no sunlight access. I would in general go for millage but after few extra years it would be good to check it out or even change.

[rich1068]

41 minutes ago, Hangie said:

Spark plugs should be done by millage only as they don't really degraded if not used.

Really? That's interesting. I've dug deep into the service history and the plugs on my RX 400h were done in April 2012 at 25k miles. So the car was 6 years old but if what you're saying is correct then it's another example of an owner getting their leg pulled by a dealer maybe? Currently my car has around 52-53k miles on it and really should only just be coming up to it's first plug change.

[rayaans]

3 hours ago, rich1068 said:

Really? That's interesting. I've dug deep into the service history and the plugs on my RX 400h were done in April 2012 at 25k miles. So the car was 6 years old but if what you're saying is correct then it's another example of an owner getting their leg pulled by a dealer maybe? Currently my car has around 52-53k miles on it and really should only just be coming up to it's first plug change.

Yep I would second that. Spark plugs degrade over usage, not time. They just sit there when not used. 

The dealers are not flexible in the servicing. For example, a 6 year old car with 25k on it will have its 6 year/60k service. Ideally, there should only be Lexus Intermediate and Lexus Full services with additional work at the required time rather than having "mileage services" as such. 

One of the reasons why I went with Lexus essential care for my wifes car as hers is going to be 6 years old with only 20k on it and they want to change the spark plugs! lol

[scudney]

just to throw a spanner 🔧 in the works would you leave a set of spark plugs in your car for 10 to 12 years assuming it takes that long to cover 60,000 miles?

[C Mclean]

23 minutes ago, scudney said:

just to throw a spanner 🔧 in the works would you leave a set of spark plugs in your car for 10 to 12 years assuming it takes that long to cover 60,000 miles?

Yup.

[scudney]

lol just to save money or common sense 

[steveledzep]

I'm sure someone will correct me if I'm wrong, but I believe the spark plug change in the US is at 100,000 miles.  On that basis, I wouldn't worry about going over 60k with spark plugs.

I don't think the cost of the plugs should be an issue, it's the cost of dismantling everything around them.  I could change the plugs in my first car (MkI Escort) in just a few minutes.

[rich1068]

3 hours ago, scudney said:

just to throw a spanner 🔧 in the works would you leave a set of spark plugs in your car for 10 to 12 years assuming it takes that long to cover 60,000 miles?

Well according to the two mechanics I've spoken to today (one Lexus specialist and one "regular" who I've known for years and is just... proper), yes.

3 hours ago, scudney said:

lol just to save money or common sense 

Because the advice I originally got from Krzysztof appears to be quite correct 

2 hours ago, steveledzep said:

I'm sure someone will correct me if I'm wrong, but I believe the spark plug change in the US is at 100,000 miles.  On that basis, I wouldn't worry about going over 60k with spark plugs.

I don't think the cost of the plugs should be an issue, it's the cost of dismantling everything around them.  I could change the plugs in my first car (MkI Escort) in just a few minutes.

I don't know about the US intervals but I'm leaving them as they are. If you hadn't already guessed 

The plugs are 70 odd quid for a set of six but it's getting to the back three that takes the time. 

[Hangie]

With spark plugs you need to remember 2 extra things:

- If you are worried about condition you can always take one (easiest access) out. This way you can measure gap between electrodes plus just visually inspect them which will give you also good overview about an engine condition.

- Spark plug won't just fail one day, it will give weaker spark to start with. That most probably will be detected by ECU as a misfire. Point is no harm done so you don't risk too much - compared to timing belt 🙂

[scudney]

leave them in the choice is yours by the way and nobody else's 😁  

[PRT68]

I would rather change at 60k miles or six years. After having problems removing on some cars, trying to get a restricted access plug out that's been in there for 12 years is something I wouldn't relish. Unless by that time you've sold the car....

[rich1068]

Thanks to all 👍

I've never really had to consider all this before. I've either run new cars that have gone after 3 or 4 years or ones more at the banger end that you fix when they break. A proper service regime is something that's important to me with the IS and RX because (imho) they're special cars.

So what I'd take from this is stick to the service book instructions but mix in a little common sense. I can live with that.

[rich1068]

All done. £208

And a very nix NX 300h courtesy car too. Too firm though. As everything is <grandpamode> these days </grandpamode>