Check out the FSM pages above, you don't actually have to unplug any wires, just have to unclip a few of them so that you can move the wire looms away so you can access the plugs.
Changing the spark plugs (2 Viewers)
- Thread starter mark71
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This gives me a little off topic lol. My 4Runner (‘07 V6) stunned me when I changed the plugs. Due to some BIZARRE contract negotiations had 3 NGKs and 3 Denso plugs. I purchased it new, that was the ‘as delivered’ norm for a window of time...
Just read thru the FSM pages and am going to print them. Why the heck does the bottom engine cover need to be removed? Some sort of precaution? Retrieving dropped tools?
Yeah it's strange, the only thing I could think of is you're bound to spill something, maybe it makes it easier to clean your mess
On the 8th Day God created Internal Combustion. On the 9th He created magnetic tools to retrieve dropped tools, nuts, washers etc.
Gr8Pmkn
SILVER Star
I did disconnect the battery when I changed mine, there was no reset, I don't even recall having to reset the clock.
Fantastic write-up and pics. I’m about to complete the same job on my 2006 LC. Thank you!!!
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To answer the question about rebooting, hook the battery back up, then I like to first push the Start button with foot off the brake so the truck only goes to Accessory mode. After a couple of seconds, the big display will inform you it's reading the data, let it do it's thing, then when it finally shows the map, I start the engine. It will start and die. Don't know why. Push the button again and it will start right up, and eventually return to normal idle, and everything will be fine. The clock will set itself, I assume it uses the nav system for that.
bloc
SILVER Star
Maybe I’m irresponsible but I usually don’t disconnect the battery for work involving two connectors that aren’t the starter or alternator.
Just make sure you do if you're touching anything to do with airbags (yellow connectors and loom on all wiring). But I bet you knew that already.
I hate messing with any of those connectors, they make them super-difficult to separate.
bloc
SILVER Star
True story... I had to replace the steering wheel on my son's Ford Ranger. Padding and cruise controls were falling apart. I had never removed an air bagged steering wheel before. I wore safety glasses, worked from outside the truck reaching in as much as possible. Airbag unit came out no problem, pulled the old wheel, put in the new one and put it all back together.
But I had my wife get in and start it the first time and test the horn after I was done. Claimed I had to be looking at it from the outside or something. I still feel terrible but I also still laugh about it.
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Replaced the plugs in my '08 last night and today. The engine is more responsive and I'm eager to punch it (which is rare for how I drive) the next time we go on a highway. Thanks for the write-up @mark71 !
If I can add two things:
1) Be very careful to grab the plastic coil seats (rubber washers) along with each coil as you pull it from the engine. I was not aware of how lose they can be and thus one fell and it took 20-30 minutes to look for it underneath.
2) I pulled both wiring harnesses from the firewall. This gave me enough leverage to move the wire bundle away from accessing the coil.
However, it was not an easy task to use my left hand to keep the wire bundle and coolant hoses out of the way while I moved the coil. Surely with all the know-how at Toyota Engineering they could've designed a better layout, right?
If I can add two things:
1) Be very careful to grab the plastic coil seats (rubber washers) along with each coil as you pull it from the engine. I was not aware of how lose they can be and thus one fell and it took 20-30 minutes to look for it underneath.
2) I pulled both wiring harnesses from the firewall. This gave me enough leverage to move the wire bundle away from accessing the coil.
However, it was not an easy task to use my left hand to keep the wire bundle and coolant hoses out of the way while I moved the coil. Surely with all the know-how at Toyota Engineering they could've designed a better layout, right?
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Posted this elsewhere, but for the record...
Done, but what a pain in the butt. Driver side is ok, pretty straightforward. The passenger side is another story. Middle 2 are easy once the air box is off. Front plug, you have to unhook the wiring harness, but not bad. I saved the worst for last... the rear plug on the passenger side. I NEVER want to meet the intern who designed those coolant pipe brackets. It would turn out badly. Or the jerk who set the torque on the wrench that tightened them down. 13 ft lb my ass!!
The last plug took as long as the rest of the job combined. Below is a pic of the arsenal of tools it took to get that last plug out. The coolant pipe bracket just laughed at my efforts to get it loose. Breaker bars, my longest box wrench to extend it, PB blaster, 3/8 inch impact wrench. It finally gave in to a 1/2 inch impact wrench. I was convinced I was either going to round off the bolt head or snap it off. Finally got them out, relatively undamaged. Wobble ratchet extensions were invaluable. Never usd a ujoint.
Finally got to the last plug and once the crap in front of it was removed, that last plug went pretty quick. But threading the bolts back in to the coolant pipe bracket was another challenge.
When they say the coil seals are loose and hang on to them when removing the coil, they're not kidding. I lost one. Almost had it but bumped a hose and it fell somewhere that I couldnt see. Removed the bottom engine cover. Wasnt there. Used the compressor and blew air all over hoping to dislodge it. No luck. Called my mechanic (Bearden Automotive, NW Austin) and they just happen to have some spares and brought a couple to my house. After I was done, I found the missing seal behind the LC in the driveway. No idea how it got there.
Elapsed time around 4-5 hours. And going over it in my head, I'm thinking that I did not tighten the bolt on the second coolant pipe bracket. Guess I'll be pulling the air box off again tomorrow.
When removing the airbox, loosen up the hose clamps on the air duct and pull the two vacuum hoses off the back of the air box. I know from experience that those nipples do break off if you dont remove the host On my 99 GS400, the large one broke off and a new airbox was very expensive. I got a brass screw in nipple from Home Depot and screwed and epoxied it into the hole of the broken nipple. Held better than the original.
Hang on to those coil seals. They're not available separately. Have to buy the whole coil.
Here's the group photo of the tools I needed to get the last plug changed (firewall, passenger side)
Done, but what a pain in the butt. Driver side is ok, pretty straightforward. The passenger side is another story. Middle 2 are easy once the air box is off. Front plug, you have to unhook the wiring harness, but not bad. I saved the worst for last... the rear plug on the passenger side. I NEVER want to meet the intern who designed those coolant pipe brackets. It would turn out badly. Or the jerk who set the torque on the wrench that tightened them down. 13 ft lb my ass!!
The last plug took as long as the rest of the job combined. Below is a pic of the arsenal of tools it took to get that last plug out. The coolant pipe bracket just laughed at my efforts to get it loose. Breaker bars, my longest box wrench to extend it, PB blaster, 3/8 inch impact wrench. It finally gave in to a 1/2 inch impact wrench. I was convinced I was either going to round off the bolt head or snap it off. Finally got them out, relatively undamaged. Wobble ratchet extensions were invaluable. Never usd a ujoint.
Finally got to the last plug and once the crap in front of it was removed, that last plug went pretty quick. But threading the bolts back in to the coolant pipe bracket was another challenge.
When they say the coil seals are loose and hang on to them when removing the coil, they're not kidding. I lost one. Almost had it but bumped a hose and it fell somewhere that I couldnt see. Removed the bottom engine cover. Wasnt there. Used the compressor and blew air all over hoping to dislodge it. No luck. Called my mechanic (Bearden Automotive, NW Austin) and they just happen to have some spares and brought a couple to my house. After I was done, I found the missing seal behind the LC in the driveway. No idea how it got there.
Elapsed time around 4-5 hours. And going over it in my head, I'm thinking that I did not tighten the bolt on the second coolant pipe bracket. Guess I'll be pulling the air box off again tomorrow.
When removing the airbox, loosen up the hose clamps on the air duct and pull the two vacuum hoses off the back of the air box. I know from experience that those nipples do break off if you dont remove the host On my 99 GS400, the large one broke off and a new airbox was very expensive. I got a brass screw in nipple from Home Depot and screwed and epoxied it into the hole of the broken nipple. Held better than the original.
Hang on to those coil seals. They're not available separately. Have to buy the whole coil.
Here's the group photo of the tools I needed to get the last plug changed (firewall, passenger side)
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Did you ever figure out what was leaking?
Adding a data point here for others’ reference.
Did plugs on the LX yesterday at 120k. Took about 90 minutes and that was with ****ing around on a few of the wiring harness clips. Pro tip - use extended reach needle nose pliers from directly above the connectors to remove them. It’s futile to use your fingers.
Plugs all came out without issue with a minimal assortment of tools. Went back in with Denso OEM torqued to 15ft-lb. Did not use anti-seize.
As much as we curse Toyota wiring harnesses - they really are carefully and meticulously installed and routed. Ever look at a big 3 engine bay? They typically look like behind my computer cabinet - a big mess of wires folded and put whenever they could squeeze them. Kudos Toyota.
To get the rear passenger plug out, unbolt the cooling lines and muscle them out of the way when pulling and installing coil/plug. In general, I actually thought the DS was more of a PITA.
Did plugs on the LX yesterday at 120k. Took about 90 minutes and that was with ****ing around on a few of the wiring harness clips. Pro tip - use extended reach needle nose pliers from directly above the connectors to remove them. It’s futile to use your fingers.
Plugs all came out without issue with a minimal assortment of tools. Went back in with Denso OEM torqued to 15ft-lb. Did not use anti-seize.
As much as we curse Toyota wiring harnesses - they really are carefully and meticulously installed and routed. Ever look at a big 3 engine bay? They typically look like behind my computer cabinet - a big mess of wires folded and put whenever they could squeeze them. Kudos Toyota.
To get the rear passenger plug out, unbolt the cooling lines and muscle them out of the way when pulling and installing coil/plug. In general, I actually thought the DS was more of a PITA.
Thanks for the detailed instructions! I attempted this today and wanted to check on 3 things with you all:
1. I lost this bolt on the air hose clamp. Dropped it and looked for a long time but couldn't find it. It is 96111-11060 but this part is no longer sold. The other clamp used is 96111-10950. Do you think these two are interchangeable?
2. I replaced the 8 seals with 11193-70010. But this looks very different from the old seals. Did you all also notice the difference in seals, if replaced?
3. I had an issue with one plug (driver side bay, closest to the firewall). I took the old one out and tightened the new one in. But the coil wouldn't sit flush which meant the spark plug wasn't fully in. However, it was tight and I had no idea why the coil still had 1 inch more to go when the plug was fully seated. So I undid the spark plug and reinstalled it but the coil still wouldn't sit flush. At this point I was scared that I messed the threads... I tried the old plug and tightened it, then installed the coil and it fit perfectly! So at the moment it is still running the old plug. I feel like the new spark plug's threads were somehow bad or was threading in wrong. I will get a new plug and try again.
Will post my plugs here tomorrow but I didn't notice anything bad (171k miles, 2013 LC). I don't know when they were last changed.
bloc
SILVER Star
If you compare the old and new plug side by side and there is no damage to the new one.. it not going in would be a mystery. Potentially very bad news, if the plug threads are damaged I have trouble seeing that fact not doing damage to the softer aluminum in the head.
I don’t want to sound harsh, but you need to learn what it should feel like when a spark plug screws in properly, starts to compress the crush washer, then tightens correctly. “Feel” is very important to develop in working on a car, and to me a plug not feeling correct when threading in is a huge red flag. If something about the new plug is causing it to hang an inch out, you should absolutely be able to notice the difference in how it is threading in, and cause you to stop and investigate.
Did you use a torque wrench? Did the new plug torque to spec and the coil was still an inch out?
Hi @bloc. I don't have the old one out now but when it was out, I compared it to the new one and didn't see any difference in threads. I even cleaned the anti-seize on the new one to look closely but couldn't see anything or feel any grinding on the threads. Also, when I put the old one back in, it went in with constant pressure (just as the previous 7 plugs did). Had there been thread damage already, the old one would go with uneven pressure and I'd feel it. I finger-tightened it almost all the way and didn't feel any roughness.
FYI, years ago messed up threads on a Honda transmission pan before so I am very careful with threading. For all 8 plugs, I first tightened using just my thumb and index finger (and the smallest possible extension to reduce angle and any chance of cross-threading). After it no longer moved, I added the ratchet and it was mostly around 0.25 turns more for the washer to crush. After that less than 0.25 turns to final tighten. No torque wrench. Same thing for removal also, just broke loose using ratchet and then finger-loosened using just an extension. All of them, including the mystery one, came out with just fingers and felt perfectly even.
Also, just thought while typing this - The threads on plugs are anyway around 1 inch too. The coil was sitting out around the same 1 inch. So that means the new plug never even started on the threads? Absolutely no, because I did the usual 20-25 turns of the plug using my fingers and then last bit by ratchet.
It makes me feel that probably the coil's rubber end was having trouble going around the plug... but then, it went fine over the old plug.
