RX450h Spark plug change

[Barry7]

Well I can't say this was easy, but today I replaced the spark plugs on my RX450h. It took me about six hours, having watched a You Tube video on the subject, I could have done it quicker but was having a good clean up as I reassembled  it. I think it would be a four hour job if you just got stuck in.

[Herbie]

Can you do it again please Barry, as a proper tutorial with step-by-step instructions and lots of photos?   

Seriously though, good job, well done. I've always enjoyed working on my own cars and you do get a fuzzy feeling inside knowing that you've achieved something.

[Mr Vlad]

Blimey 4 hours if you cracking on? What makes changing the plugs take so long?

Good job done none the less. Well done.

[rayaans]

5 minutes ago, Mr Vlad said:

Blimey 4 hours if you cracking on? What makes changing the plugs take so long?

Good job done none the less. Well done.

On the RX its quite a fiddly job - have to almost disassemble half the engine from what others have said

[Herbie]

16 minutes ago, rayaans said:

On the RX its quite a fiddly job - have to almost disassemble half the engine from what others have said

Yeah, the RX300 was the same. I got the guy who did the LPG conversion to change the plugs at the same time, knowing that he'd be doing a lot of dismantling  

[flookyk]

I think the Lexus dealers have it as a 3 hour job.

When I got mine done earlier this year it was by a local trusted garage, took them 3 and 1/2 hours but they only charged me for 2 hours.

[Barry7]

The YouTube vid I followed is http://www.howtoautomotive.com/videos-2/2018/5/24/how-to-replace-the-spark-plugs-on-a-2010-2015-lexus-rx450h-hybrid?rq=rx450 Take a look and then tell me if I took too long to do the job........ I think I did ok!

[Vadim]

Did the replacement this weekend.

As it is done only every 120k miles, there is always enough of dirt you want to clean by that mileage. You may also wish to check / clean the throttle body, MAF sensor and whatever else come on the way. This is the only opportunity to get access to many of that parts, so it makes sense to do it properly and not try to save 20min. If I paid for this work, I would still ask mechanic to spend extra time to clean everything properly.

Overall - 6 hours including all cleaning and oil service (after watching some very useful videos on youtube, and having all the tools required).

The most difficult part was the rear bolts holding EGR cooler bracket and the air intake bracket - not saying about very tight access, a dozen times the bolts fell down during assembly / disassembly, so that at least 30 min went of searching and fetching them from under the car (some fell down to surface, some stay on the subframe and are difficult to spot).

The job costs > £500, and it is worth to DIY if you have the time and experience in repairing your car and good memory of what goes where. Once done you may well wish to proudly show your oil-covered hands to your friends and boast about the accomplishment.

New and old spark plugs:

[Barry14UK]

Interesting comparison of old and new plugs.  Did you think to measure the respective gaps?

I asked Lexus whether they were able to defer the plug change on my car as they had done less than 50K miles by the set time.  Unfortunately, they declined, so were changed prematurely at service.

                                                                                                                                                         I have had v8s and v6s with plugs aligned front to rear that could be changed in minutes and having the rear bank so involved to get at is a pain.

I would assume the 4 cylinder engine that replaced the v6 is easier to work on?

[Bluemarlin]

On 8/16/2018 at 8:00 AM, flookyk said:

I think the Lexus dealers have it as a 3 hour job.

When I got mine done earlier this year it was by a local trusted garage, took them 3 and 1/2 hours but they only charged me for 2 hours.

Mine were done as part of the 12 year service by Lexus Battersea (now closed). If I remember correctly the cost was roughly an additional £150 over the price of the full service.

[Paul Mingay]

20 hours ago, Vadim said:

Did the replacement this weekend.

As it is done only every 120k miles, there is always enough of dirt you want to clean by that mileage. You may also wish to check / clean the throttle body, MAF sensor and whatever else come on the way. This is the only opportunity to get access to many of that parts, so it makes sense to do it properly and not try to save 20min. If I paid for this work, I would still ask mechanic to spend extra time to clean everything properly.

Overall - 6 hours including all cleaning and oil service (after watching some very useful videos on youtube, and having all the tools required).

The most difficult part was the rear bolts holding EGR cooler bracket and the air intake bracket - not saying about very tight access, a dozen times the bolts fell down during assembly / disassembly, so that at least 30 min went of searching and fetching them from under the car (some fell down to surface, some stay on the subframe and are difficult to spot).

The job costs > £500, and it is worth to DIY if you have the time and experience in repairing your car and good memory of what goes where. Once done you may well wish to proudly show your oil-covered hands to your friends and boast about the accomplishment.

New and old spark plugs:

Thought they were changed at 60k miles ?

[Spock66]

10 hours ago, Paul Mingay said:

Thought they were changed at 60k miles ?

Yes that's correct, or 6-years whichever comes first.

[Vadim]

On 9/4/2023 at 1:13 PM, Barry14UK said:

Interesting comparison of old and new plugs.  Did you think to measure the respective gaps?                                                                      

Thank you. In the old plugs the upper part (the one on the “hook”) was materially eroded. I did not measure but it seemed about 0.3 mm shorter. The replacement plugs were the same brand, same code.

I am not sure whether the plugs have ever been replaced before. Probably not, because I found absolutely no traces of prior work on the air intake and around, and I don’t have prior service history to check. The car is 207k miles at the moment.

I think with 50k miles you would be safe to go for another 50k despite any age. Lexus might have demonstrated overadherance to preemptive servicing in your case.

[Vadim]

4 hours ago, Spock66 said:

Yes that's correct, or 6-years whichever comes first.

I probably mixed the plugs replacement interval with something else. Indeed it is 60k miles (recommended).

[Spottedlaurel]

I have shared photos on here before, but this is what mine looked like after 60k:

That was at eight years old. The dealership and I could see no point in changing them at six years when it would have been on 40k, and I couldn't see anything within the service recommendations about them having to be done on anything other than mileage.