I did my plugs today with about 99,000 miles on the car. The job was pretty easy, some of the tips by the OP were helpful to read over ahead of time.

My old plugs actually looked 'very good' but I do feel the car is running smoother now. What's interesting to me is my old plugs, as well as all the ones shown in this thread by others, have a lot of 'burn marks' on the porcelain where it joins the metal base. That can't be good....

The hardest cylinder, by far, was the third one back on the passenger side. (#6 if Toyota uses numbering like an American V8). There was no way the coil pack would come out without hitting the strut tower, even with some careful prybar use on the engine. I removed the engine mount nut - that helped some but still not enough. Finally, my years doing body work paid off (!) as I used a flat faced body hammer to tap flat a small portion of the strut tower by about 3/16". This clearance, along with the prybar, just allowed to coil pack to come out. The arrow in the photo shows the area I flattened. Prior to doing this I made sure nothing on the other side of the strut tower would be affected.

On the pry bar....I used a piece of 3/8" plywood about 3" square between the prybar and the valve cover. This did well to spread the force of the pry bar over a larger area. I'd hate to crack one of the cast aluminum covers....I'll bet they're not cheap or easy to replace.

 

I also want to comment on the topic of using anti-seize compound on the threads....my old plugs came out squeaking the whole way. If you've ever had a galled thread in an aluminum head, you'll know how uncomfortable that sound is, especially times 8.

I used a nickel-based anti-seize on the new plugs and they went in much 'happier'. The brand I used is CRC but I'm not particular to that brand.

As for 'factory guidance', Ford, in their 11 page TSB for fixing broken-off spark plugs in their modular engines, recommends using nickel-based anti-seize on the new plugs. My comment to Toyota or any other OEM that recommends against using anti-seize because it can lead to over-torquing is:

1) Few people, even your own techs, are using a torque wrench to install plugs anyway. Most people go by feel. It's not hard.

2) If a person can't tell he's stripping a 3/4" long set of threads on a spark plugs, he shouldn't be working on an engine anyway. If a 3/4" long set of threads gets stripped by the difference in torque between dry threads and greased threads, they probably were not good threads to begin with.

3) If you know anti-seize compound will increase the effective torque, issue a reduced torque value for use when anti-seize is used.

 

When I did this DIY write-up, I was challenged about using anti-seize. Like you, I was comfortable with using it and have done so with every vehicle I've done spark plug changes on over the last 35+ yrs. I use very little. I will say that I won't do my V10 Ford Triton Motorhome. Lots of scary stories of broken plugs in those engines (as you state), from those trying to remove them. A little anti-seize would have solved that..

 

Nice DIY! Just changed spark plugs today so my couple cents:

1. My LS460 is 85k and removing all plugs I noticed they are in perfect shape. If I saw them before I wouldn't change them as they looked very good. However, after changing I definitely feel the improvement so go and guess.


2. These are kind of plugs that are not supposed to be gapped. if you check the gap and it's incorrect consider the plug defective and get a new one.

3. If you read the description on the MAF cleaner bottle it's saying "not for ..... MAF types". (I think vortex is one of them, don't remember now). MAF sensors on this LS not supposed to be cleaned. I cleaned mine when I bought this LS and though I cleaned very gently I felt performance degradation after all and I realized I ruined one or both sensors. After that I bought ODB2 with soft, read how to test the MAF (it should show less of equal 0.26 g/sec (details available on workshop manuals), tested and had to buy one new. If you guys happy with cleaning the sensors you got it, but I just share my story. I think as long as it's within the Lexus spec there is no reason to touch it

 

I believe you're referring to "Karmen Vortex" type MAF sensors, which haven't been used in LS since the LS400. That's an older style MAF and most manufacturers I believe stopped using them after 1994. If you had issues with your MAF after cleaning, it shouldn't have been caused my the cleaner itself.

 

I was going to say, God I hope not, I just cleaned mine the other day...figured with all the salt on the roads it was a good time. It's pretty important to keep these things clean, it can effect fuel economy and engine preformance. And they won't always throw a check engine light if they're dirty either,the computer will just compensate and take away fuel...which could lead to lean misfires, hesitations, etc.

 

I agree with you. Cleaning is almost always good. However, we don't know if cleaning required and what is sensor condition after cleaning (maybe it was bad and cleaning didn't do anything). Toyota/Lexus way to test them is to:

1. Visually inspect for any damage.

2. Connect TeachStream and verify with engine turned off they show less than 26g/sec and 27g/sec respectively.

http://workshop-manuals.com/lexus/ls...nt_inspection/

This helped me to identify the bad sensor (maybe it was not good even before cleaning and I just finished it) --> it always showed 31g/sec so I replaced it and make sure the other one is within the spec. If not this test I would buy 2 new ones to make sure things are good ).

ODB2 cable and soft are about $30 on ebay and it's faster to test the specs than removing and cleaning them

P.S At least its a good idea to verify the specs after cleaning

 

Hello Folks,

Just did my spark plugs over the weekend @65K miles. To make this job easy, you MUST have (2) 4" extensions in order to remove the plugs with no issue. I'm going to fast forward other steps and move to the spark plug step. I hope this will helps other folks.

Step1: connect all tools as shown on image plus a ratchet
Step2: loosen the spark plug couple turns until you feel that you can turn with your hand.
Step3: remove the ratchet and (1) 4" extension and start loosen until the plug is out.



Reminder:
Make sure you wait 6-8 minutes before you remove the battery.
You must remove the coil and the seal gasket together to make the job easy.

 

Great going on posting a photo.
Visual examples do wonders.
Thanks a lot!

 

Excellent info for the DIY'er. My eyes glazed over just reading about it.

 

Don't be intimidated...it's far easier than you might imagine.

 

Yeah, take it from this guy ^^^^!!
I swear the water pump repair had me a bit stifled, but it was much easier than I could have ever imagined, thanks to Chris.
Between him, Doublebase and Devh (were are you buddy), the LS corner is in great hands.
And actually, come to think about it (the water pump repair)...it was actually kind of fun...

 

thanks for sharing..

 

Great write up. Did mine last week. Got the plugs from ebay at $6 each. Only have 72000 on my 2007 LS460.
ECU had to be removed as well as the bracket that holds it. Front two plugs on left and right needed a bar to free the ignition coil. Bolts for battery case install was a problem but figured way to align and start. Should have waited for the ECU memory to be loaded up prior to starting. Got check engine codes but reset and everything worked fine.

 

Did mine and found that using a large flat head to get the spark plug tube gasket/seal out made it so that the engine did not have to be rocked/pryed.

thanks for the write up!

When I took to lexus for the 75,000 service they said it needed plugs when I told them I had just completed it their minds were blown. the service advisor when on and on, and on.... about how the techs at my dealer complain about the job.

oh well a couple hundred saved.