w84me

I see some taking it off, others just removing the cowl. is it really that hard to do by just removing the cowl? Looks like there is almost enough room to not have to remove anything?? Any experience out there doing plugs ?

christcorp

I've looked at a LOT of youtube videos. Some show that they are able to do it without removing the intake manifold, but they do remove part of the back panel between the engine and underneath the wipers. I haven't tried it. I did have my spark plugs replaced at 100,000 miles but had the dealership do it. I did have a Coil pack go bad; fortunately it was one of the front ones so I replaced that in about 3 minutes.

danielnas

i did mine at 160k km. Just removed the air intake, air filter ducts and some wirings and vacuum hoses. No need to remove the cawl or wiper assembly.

w84me

I did the front 3 yesterday just to get familiar with how the coils come out and how the connectors will behave. its nearly impossible to get the connector off w/o breaking the secure tab. so plan on buying some replacement connectors if you do this job and have them ready when you do the back 3. will let you guys know if I am able to do this by just removing strut brace and cowl. those are not too hard, and I wouldnt mind having the extra room to work when repairing the connectors. if I'm going to the trouble of removing the intake, then my OCD is gonna wanna soak it to clean out the grunge on the inside, not sure if I want to take that long to do this job. I've got a V10 waiting to replace plugs and injectors and want to get to that before cold weather sets in.

christcorp

Definitely keep us informed. I haven't had to replace the plugs, because I had the dealer do it, but I have had to replace one of the coil packs up front. I'd like to know how easy I can get to the back if I need to change those coil packs.

For what it's worth..... I disconnected all 3 coil packs in the front, while troubleshooting the OBDII code for a bad coil pack to make sure it changed when I moved them around. I had no problem taking off any of the 3 front coil pack wire connectors. Took them off and back on a number of times. Never broke one tab. I've worked in electronics for 40+ years. We have many similar connectors. I've gotten use to using a scribe or knife blade and removing plugs without breaking anything. Remember, the purpose of the tabs/plugs is to keep a good connection ON. Not for it to be easy to take off. But they definitely can come off if you know how.

w84me

I'm usually pretty careful with getting connectors off, even tho they looked new, these babies were brittle. chalk it up to 13 years old, 146K miles, lots of Texas heat. I've ordered new connectors and can easily remove the pins from them, hopefully the factory ones are built the same way, will make replacement a breeze.

craig72

I did mine some time ago, probably close to needing it again (190k). I did end up taking the upper manifold out of the way. Was not difficult, and made the job much easier.

w84me

Did this job last night. Didn't remove intake, but did remove cowl. Highly recommend removing cowl at a minimum. Removing the intake is probably a wash in time, and would make the job much easier. The biggest issue you will have is the wire harness that runs at back of engine, over top of the valve covers. Loosen as much of this harness as you can. Remove Intake so you can access more wire harness to loosen, and in my case, I had to crawl onto engine to get to cyl 3 and 5, entire 5 and 3 part of the time. you will also need to remove the intake support that covers cyl 1. Once you get harness as loose as possible, you will still need to stretch the harness to get this done.

I used an 11" swivel, magnetic 5/8" spark plug tool. You need the swivel as you enter/exit the spark plug tube.

I started with 5, then 3 then 1. Got the hard ones out of the way while I still had energy.

The scariest part of this job is the torquing of the plugs. I'm so afraid to strip a spark plug thread. I found that by using a 3/8" rachet, it helped to find where the seat of the plug actually was. turning the rachet near the top, rather than at the grip, you can feel when the plug seats. then you can proceed to torque, and at this point, it shouldn't take but a slight turn to hit 13 ft lbs.

I highly recommend doing a trial on the front three to see if you have brittle coil connectors. Mine were so brittle that just pushing the tiny retainer open would cause the retainer to snap off, sometimes just removing the white holder would cause the connector to shatter. Its super easy to replace the connectors. It just seems to be these particular connectors. Other connectors on the car don't do this.

Here are a few photos with cowl removed.

w84me

Here is the bed I made myself so I could lay on the engine and access cyl 5

w84me

Here is the connector after it was replaced. No need to solder for these. Just replace the connector. That was nice. I started replacing connectors in the back, in case I broke one, could still put the car back together and get more for the front later. Turned out not necessary, and by the time I did the front, I was replacing a connecter in less than a minute.

Hayk

iTrader: (1)

Thank you for the photos. Looks very similar to the 1MZ-FE spark plug change on my 98 ES300. Only difference is the cowl.

w84me

I recently did my 99 Solara 1MZFE. The Solara was much easier than this, for one I could stay planted on the ground while doing it! Also didn't have a rats nest of wire harness to contend with. It was just a little tight back there, but not too bad.

chuyrobles

I replaced plugs twice on our ES350. I removed the intake plenum both times. Back when I first did it, that was the only method on youtube. Then someone did the cowl method. I looked at it carefully, but I will stick to the intake method. One advantage, with the intake pluming opened, you can clean up the throttle plate assembly. You also get up close with some of the vacuum lines; the second time I did the plugs, I spotted some that had cracks; so I replaced those.

Wilson2000

On the down side, removing the intake can disturb hoses, connections, and misc. parts which can lead to related issues in the future. Of course, struggling to do the job with limited accessibility can also lead to damaging parts one is working around. It happened to a CL poster who was getting codes after replacing some of the rear coils. Turns out he, or a mechanic, had damaged some of the associate wiring while working in the tight space.

I've replaced the plugs on an Avalon without removing the manifold or the cowl. It wasn't easy, but I have a lot of experience and tools, all of which helped make it possible. Or, perhaps the Avalon has more room, but I doubt it.

w84me

as far as taking the intake off, I would separate it from the throttle body and any electronics and soak it in Totally Awesome for a few days. That will remove the build up w/o almost zero work.