Spark Plugs - 2015 Lexus RX350 167k miles

[Hillbilly Deluxe]

These were over 45k miles overdue according to Toyota / Lexus on this engine. I thought they looked pretty good.

I replaced with the same Denso OEM and replaced the rear 3 coils also with Denso coils (not OEM).

I forgot to order a new PCV valve to do at the same time but it’s easy to get to.

 

[incognito_2u]

So, How many miles, total, on these plugs Please?

 

[Hal-9000]

Why replace the coils, did they all go bad at the same time?

 

[JeffKeryk]

I just did the plugs on a '16 Corolla with 150K. Looked the same. Those Denso plugs are amazing.
Think I paid $12 a piece on RA.

 

[ctechbob]

Why replace the coils, did they all go bad at the same time?

WAG is that they're a big pain in the butt to get to, so you replace as much as possible while you're in there to keep from having to do it again should something fail.

 

[The Critic]

WAG is that they're a big pain in the butt to get to, so you replace as much as possible while you're in there to keep from having to do it again should something fail.

I suppose. But the rear ones on a 2gr-fe are not even that difficult to get to. Especially on a RX350.

 

[Hillbilly Deluxe]

I suppose. But the rear ones on a 2gr-fe are not even that difficult to get to. Especially on a RX350.

I’m a little shocked in your reply.

I’m a DIY weekender and don’t do this everyday all day.

I’ll be honest and say it took me over 90 minutes to get to the rear coils / plugs.

As for why I replaced them, The plugs were overdue by 45k miles and I didn’t want to have to chase down a check engine light, diagnose a misfire and spend 2+ hours replacing one coil after just having everything accessible.

I guess I’m weird.

 

[Hillbilly Deluxe]

So, How many miles, total, on these plugs Please?

167,000

 

[artbuc]

I’m a little shocked in your reply.

I’m a DIY weekender and don’t do this everyday all day.

I’ll be honest and say it took me over 90 minutes to get to the rear coils / plugs.

As for why I replaced them, The plugs were overdue by 45k miles and I didn’t want to have to chase down a check engine light, diagnose a misfire and spend 2+ hours replacing one coil after just having everything accessible.

I guess I’m weird.

You are not wierd, at least by my standards. Makes perfect sense to replace all three back coils in certain situations, ie very difficult access, high mileage, intent to keep car for the duration and long trips to remote places.

 

[doublebase]

I suppose. But the rear ones on a 2gr-fe are not even that difficult to get to. Especially on a RX350.

Not difficult to get to? They’re awful, I haven’t done them on an RX350, but a Camry or Avalon, or ES350, the intake has to come off and cowl where the wipers are housed.

Not a lot of fun... think I might push mine out to 130,000 or so before I tear into it.

Do you work on Toyota’s? I would think only people that do these every week would consider these things easy. I’m nit saying it’s the worst thing ever, just a little too much work for plugs on a typical passenger car/engine. IMO.

 

[The Critic]

Not difficult to get to? They’re awful, I haven’t done them on an RX350, but a Camry or Avalon, or ES350, the intake has to come off and cowl where the wipers are housed.

Not a lot of fun... think I might push mine out to 130,000 or so before I tear into it.

Do you work on Toyota’s? I would think only people that do these every week would consider these things easy. I’m nit saying it’s the worst thing ever, just a little too much work for plugs on a typical passenger car/engine. IMO.

On the SUV's, removing the cowl actually gives you enough room to remove the rear coils without removing the intake. It isn't fun, but it can be done.

But it only takes 30 mins to remove the cowl and intake on a 2GR. Not worth spending money on coils upfront, IMO.

 

[doublebase]

On the SUV's, removing the cowl actually gives you enough room to remove the rear coils without removing the intake. It isn't fun, but it can be done.

But it only takes 30 mins to remove the cowl and intake on a 2GR. Not worth spending money on coils upfront, IMO.

You’re fast, I don’t think I could do the intake and cowl in a half hour...well I could, but I’d break every connector and vacuum line.And probably lose half my bolts.

 

[Hillbilly Deluxe]

On the SUV's, removing the cowl actually gives you enough room to remove the rear coils without removing the intake. It isn't fun, but it can be done.

But it only takes 30 mins to remove the cowl and intake on a 2GR. Not worth spending money on coils upfront, IMO.

I’m sorry but it takes a lot longer than 30 minutes to remove the cowl, wipers, wiper motor, throttle body, lntake plenum, etc. it might take you and other experienced mechanics 30-45 minutes for all that, and please include time to collect tools, setup, etc.

There’s a lot of time you full-time techs don’t talk about on forums that DIY’ers experience at home because we don’t have a desiccate shop space to work with.

You also get paid over 2 hours to do this job and I’m glad that good techs can do it in less AND do
It by the book, complete a professional job and have everything back like factory.


Question - if you do this job and don’t replace the three rear coils and one goes out 10k miles later, do you charge the customer for the labor to replace the coils? Do you then replace all three?

 

[JMJNet]

I agree to replace the rear coils.

 

[1000MPH]

Why is it always the #4 that looks different? TBF the miles are high but the age is not. I replaced mine before the recommended mileage interval because I was reading about difficulty removing 9-10 year old plugs.

 

[atikovi]

Why replace the coils, did they all go bad at the same time?

Did the same on my Explorer. The intake has to come off to replace the rear plugs, and I have been getting misfires on a front and on a back cylinder. Got 3 new coils and put those in the back, then replaced the bad front one with one of the good rear ones. And "good" is a relative term. All the old coils had been replaced not long ago but with no name junk.

 

[slacktide_bitog]

Are coils a common problem on the RX/2GR?

If not, there is no need to replace them. But if you pull the intake, you might as well replace the valve cover gaskets.

 

[The Critic]

I’m sorry but it takes a lot longer than 30 minutes to remove the cowl, wipers, wiper motor, throttle body, lntake plenum, etc. it might take you and other experienced mechanics 30-45 minutes for all that, and please include time to collect tools, setup, etc.

There’s a lot of time you full-time techs don’t talk about on forums that DIY’ers experience at home because we don’t have a desiccate shop space to work with.

You also get paid over 2 hours to do this job and I’m glad that good techs can do it in less AND do
It by the book, complete a professional job and have everything back like factory.


Question - if you do this job and don’t replace the three rear coils and one goes out 10k miles later, do you charge the customer for the labor to replace the coils? Do you then replace all three?

You really don't need a dedicated space. If you have a reasonably organized basic toolbox, a table for organizing items and a 3/8" drive impact wrench/driver, the job can be executed by any reasonably competent DIYer. A lot of these jobs are not that difficult if you stay focused, even if you do not do them daily. Study the instructions, gain an understanding of how the components are assembled and you will be in a good position to tackle the work. I think you might be underestimating your capabilities.

To answer your question, yes. Spark Plug replacement is a maintenance service by itself. Coil replacement is not part of the service. We cannot reliably predict coil failure; many of them last another plug interval without issues.

 

[bbhero]

I was going to say that coils generally don't go bad... It's not like old school rotor and distributor cap.

My coils in my car have 351,000+ miles on them.

I believe bad plugs can cause coils to go bad.

If the vehicle here had 167k mile plugs on it and the vehicle ran good no codes for any cylinder misfires.... Then those plugs actually didn't hurt those coils.

Though I certainly don't knock anyone for changing their coils. Each to their own.

 

[JeffKeryk]

I was going to say that coils generally don't go bad... It's not like old school rotor and distributor cap.

My coils in my car have 351,000+ miles on them.

I believe bad plugs can cause coils to go bad.

If the vehicle here had 167k mile plugs on it and the vehicle ran good no codes for any cylinder misfires.... Then those plugs actually didn't hurt those coils.

Though I certainly don't knock anyone for changing their coils. Each to their own.

I have had only 1 coil failure on a modern car.

If you do replace coils as a service item, make sure you don't get 2001 Toyota Tundra 4.7 fakes.
Don't ask me how I know.