Ramjet44

Be careful about adding lubricant to the threads if the service manual doesn’t call for it. The torque specs were probably determined without lubricant. If you apply lubricant and then apply the service manual torque you could end up over tightening.

hybridanim

iTrader: (9)

sorry to be a noob, but what EXACTLY is cross threading? Is it when you turn the spark plug the wrong way when installing the new one in?

LyleBeach

iTrader: (1)

Cross threading is when you don't quite have the plug threading correctly (slightly cocked/tilted) then you try to force it down and it actually starts cutting a new thread path.

hybridanim

iTrader: (9)

^^^ thanks man. totally appreciate it!

Initial_K

iTrader: (2)

Any Guide for the IS250? Is it the same or much more difficult?

Also are these the OEM spark plug?

http://www.lexpartsworld.com/scripts...?idproduct=546

pdivizzle

i work at a lexus dealer...these IS models are cake to work on..i timed myself once 5 minutes to remove the entire manifold..makes your life alot easier with the right tools

IS350HKS

iTrader: (4)

thanks for the write up, it will be really useful for me pretty soon

RocketGuy3

iTrader: (1)

I've heard that iridium plugs in the IS don't need to be changed as often as Lexus recommends... generally I don't want to miss manufacturer recommended intervals, but 60K does seem kind of early to change spark plugs, doesn't it?

Kurtz

iTrader: (1)

Not really, considering the direct injection system.

Honestly, given most folks aren't going to keep their cars for 180,000 miles you're talking a difference of changing once or changing twice over the life of the vehicle.

RocketGuy3

iTrader: (1)

I plan on keeping my car until I die. ... or she dies, whichever comes first. It's the first car I bought on my own.

But I didn't realize DI can be more harmful to spark plugs.

trnsprtr

Thanks for the great how-to. My Lexus dealer quoted me 700 for the 60k service. I've loved the car since it's had 4 miles on the odometer but that dealership just keeps reminding me over and over why they're likely to never get another dime out of me.

PandaBear

iTrader: (1)

It's not really DI being more harmful to the plugs, but more because the high compression causes Toyota to use a colder plug to avoid ping, causes more plug fouling, causes them to use the 3 prong plugs and more frequent changes.

Those old plugs they pull out looks like they are in EXCELLENT condition and would last another 30k: the center electrode is sharp and long, the color looks great, the gap is still LIKE NEW. Unless they predict micro fracture in the ground electrode (unlikely since traditional plug designs have been in turbo charged and super charged cars and works fine) I don't think there's anything to wear out within only 60k.

SC3coupe

iTrader: (4)

Why does the dealer seem to charge alot for this particular task.. or is the cost not clear when mixed with the 60k service?

Can't possible take more than a factory trained mechanic more than 1 hour of labor.

As to spark plugs usually hand tighten then 1/2 - 3/4 turn with a wrench is good to go.
This is actually on some of the instructions on NGK spark plugs.. but works on denso too. Be careful with the clickers sometimes you could overshoot and miss it on such low torque
I never oil my plug threads also.. but hand start carefully. I believe oil messes up the torque (manual torque are assuming dry threads)..

Kurtz

iTrader: (1)

Same reason they charge $150 for a "10k service" when it's nothing but an oil change. Because customers don't know any better.

lobuxracer

iTrader: (2)

There's a plug torque spec for a reason. If you overtighten, the shell distorts, the center electrode isn't where it's supposed to be, and it affects heat range - typically making the plug run hotter.

Use your torque wrench. There is no better way.