genijet

I had my plugs replaced when I had the timing belt replaced. And by the way, have the water pump, and drive belts done also.
Carl

hsmac

do spark plugs really affect the coils and fuel efficiency etc. so much so that they need to be changed "on schedule?" i remember doing research before and determined that not changing them if still working was not a big deal.

hsmac

so this seems like a lot of work. i've never changed the rear plugs with or without the TB off, but i'm wondering if the amount of work it takes to remove the TB negates any of the convenience of having it removed to change the plugs?

salimshah

Rear plugs can be removed and installed without taking the intake/TB off. You need a set of adapters. I was unable to use torque wrench to tighten the plugs though.

Salim

artbuc

Denso designed their iridium plugs to go 200k miles before performance degraded. I read (think I still have it somewhere) the paper they presented to the SAE with data proving their accomplishment. I assume NGK plugs are just as good. The problem with leaving plugs in too long is possible thread damage when removing. I always pop them at 50k, clean threads, apply a dab of AS and reinstall. I have replaced several sets at 120k miles and could never tell any difference with new plugs.

salimshah

Art, I do not disagree with your assertions here. The recommended service (replacement) for the plugs is 110K miles. If you get more which most likely you will it is all bonus. I had 1/6 fail at 125K and the all Including the failed one looked good. When I put the new ones in, the coilpack (of the failed plug) went out within 1000 miles. It all can be a coincidence.

Just like timing belt ... how many replacements would an owner save by extending the interval?

Salim

artbuc

Yes, I always replace at or before 120k but have never seen a difference between new and old. Maybe I have just been lucky.

Drcoffee

my 2008 Sienna has 151,000 miles on the original plugs and the mpg is the same as it was at 50,000. Plug issues will show up as an immediate loss of mpg. I tend to believe the 200,000 mile lifespan theory.

shervink24

You guys are tearing yourselves up for no reason. There are 2 videos on YouTube that helped me. I'm semi disabled and can't get down for oil changes and things of that nature. For the one behind driver side you take cruise control cable off and the mount for cruise control screws. You can now get the driver one out by dropping your tools into the spark plug hole and attaching them like Legos. Once the plug is loose use a flat head to separate the tools. This is the hardest plug overall in my opinion. Once you have the plug and plug socket left you wrap your middle finger with duck tape sticky side out and put your finger inside to remove everything.

From this side you can get the middle plug out real easy with almost no tool separation except for the wrench.

The passenger side requires pcv tube removal and the tube on the cylindrical object to be removed. Then hopefully you have medium to small hands and you can get the plug out.

I DID NOT REMOVE ANYTHING EXTENSIVE AND THIS TOOK ME 4 HOURS JUST FOR THE BACK 3 PLUGS BECAUSE OF HAND SPACE.

​​​​​​​13 lbs to torque plugs. I accidentally over tightened but didn't strip the plugs. Hope this helps. DO NOT NEED TO REMOVE ANY MANIFOLDS. THIS IS NOT THAT DIFFICULT TO DO.

hsmac

coils are not part of routine maintenance, right? is there a standard length of life for them?

mind posting the links to the videos? are you saying you were able to torque the plugs and/or coils? my only reservation is that this took 4 hours vs. the 1 that someone else claimed.

shervink24

All you have to do is type lexus rx300 spark plug replacement. It's the one with the picture of the spark plugs lined up. Made it really simple. I reused my coils. I've had another car that had bad coils and it would throw an engine code. So unless that happens they should be fine.

shervink24

Use this video. On the passenger side you do not need to undo the 2 screws that remove the cylindrical object with the tube connected to it. You can just undo the tube, and the PCV tube from the PCV valve. This will save you time, and is all you need to get the far left back plug out. Also its the only coil where undoing the coil makes it easier to remove the electrical connector.

hsmac

thanks i actually watched it already. how did you torque the plugs?

shervink24

I didnt use a torque wrench. I used a standard sized socket wrench. I first put anti seize on the plugs and hand screwed them in. Then attached the socket wrench and gave a few good turns until tight. I started another thread about how I may have over tightened. But then again I drove the last 300 miles, and floored the car a few times so its fine. Dont force it tight. You only have a little bit of tool play with the space you are given to work with. Just get them on a few clicks tight.

shervink24

Do I get some type of props for this video link. Jeez guys. Only an auto shop should suggest a manifold removal so they can charge you up the A for labor. Its really easy. No manifold removal. Even I can do it and I have a nerve problem so I cant stand on my feet too long. Hope this helps everyone. I appreciate any props, or likes, or ranking bumps. Thanks.