Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert! (3 Viewers)

[2001LC]

Hold spring with needle nose pliers. Turn CCW (counterclockwise) as you press in. Once you hear/feel spring click in. Turn CW to sung down. Make sure spring lines-up with center of boot, when you place boot on.

 

[4LoforSno]

Thanks @2001LC

 

[NE Snowman]

Putting this on my list, 03 sitting at 181k. Plugs last replaced 2018 @ 120k. Seems premature to replace these yet… thinking just pull coils, replace rubber with denso kit. Leave plugs and just recheck torque. Be nice to push plugs and coils to 200k/another year, but don’t need one blowing out!

Plugs were installed at a dealer so not sure what torque they got originally installed at.

 

[NE Snowman]

Doing plugs and rubber today, noticed the new springs and rubber are slightly different. Enough to be concerned about?

Also; DONT ignore these, so far all of mine have been “loose”

 

[2001LC]

The Denso boot kit is slightly different than some older factory coils boots. Not a concern! They work great, for 98-up 4.7L & 5.7L.

 

[NE Snowman]

This was an easy job! Take your time feel the threads as they thread in and out. My plugs were last done at the dealership about 6 years 40k miles. One plug was finger loose, the rest I barely had to put any breaking force on!

I will have to add coils soon, I could see 2 with some hairline cracks, ones been replace before. It also appears that my spark plug seal for driver side 2nd from front is starting to let oil in the spark plug hole.

 

[fussychicken]

Adding another data point:

I've got 245k on my 2001 and have the dreaded tick from what appears to be the drivers side. When I read this thread I started to get a little excited hoping this might be my issue. I've only had my rig for a year and didn't get any service records so I'm not sure last time this was done. Went with new Denso SK20R11 instead of the IK20TT.

For disassembly they were all somewhat loose and a few didn't even need a ratchet. I was able to twist out with my hand. The plugs that came out were also SK20R11 and looked pretty good. Many of them were sticky on the threads. Not sure if that was oil or previous thread lock? They all came out pretty easy so I'm guessing that maybe it was just some oil or something? All the electrodes looked pretty good. They didn't look very old.

I had purchased the Denso kit for seals and boots, but surprisingly all of mine were in really good shape. Still soft with no cracks. Maybe these were changed during the last plug install?

#7 is the hardest by far, but this is what worked for me: I used two 3" extensions which allowed me to click them in series and then take them out in parts. To get the last section out I used some needle nose pliers. This worked really well and didn't require disconnecting the AC lines or anything like that.

All was going great until I was buttoning everything back up together and when I was installing the airbox assembly I SNAPPED one of the bolts that holds it onto the valve cover. FML!!! I couldn't believe it. Took me hours to try and drill it out. Kind of a mess. Still need to get a new tap and see if I can save the threads.

And then the moment of truth when I cranked it up for the first time. Tick tick tick tick tick tick.... Oh well. Guess I'm going to need a new exhaust manifold after all....

Anyway, huge thanks to all the tips and posts in this thread. SUPER helpful. Even though it didn’t fix my tick, it was still good to get new plugs in there at a slightly higher torque.

 

[Dave JR]

Glad you guys are here. This is my third 2UZ and first LC, and have never heard of this problem before. After wrapping up the TB job, i decided to replace the plugs even though the previous owners mechanic just did it. #3 was my last one and when i pulled out the coil, i had a panic attack. The sleeve was brown with soot and i imagined a cross threaded plug scenario. After a quick google search, i found myself back here.

I reached in and found #3 plug was totally loose. After looking at the plug gasket and mating surface, there is a distinct clean ring showing there was a seal. The gas must have been coming up the stalk through the back of the gasket.

I guess i have never had this problem because i always estimate the torque by hand. I feel for the washer to crush completely and stop. It comes out to be between 18 and 20 ftlb.

Maybe this can explain my slight stumble on cold startup and the soot in the throttle body? The TB job went so well, when i was hand cranking the motor to double check my timing, i heard a whoosh noise from the driver side bank on each revolution. After 4 rotations and a tired arm i decided it was normal. Got lucky on this one. Thanks again for this thread. Heading out to my tundra now to retorque the plugs i put in a few months ago… cheers.

 

[urist]

[[EDIT: this thread is so long that I looked through most of the pages but failed to see that 2001LC had commented with the way to get these springs to insert correctly here...and it was at the top of this page . Since search terms failed for me via mud's search feature and Google, I'm adding some keywords here to make this more searchable:

ignition coil boot replacement
replace coil boot spring
coil boot spring
denzo coil boot spring
how to insert spring denzo ignition coil

Thanks.
]]

I was doing a full spark plug ignition coil boot replacement today due to a couple of tired boots in my set. I ran into the same problem that @mdcoa ran into, quoted from an earlier post in this thread, which is why I'm replying here instead of a new thread:

Put new coil boots on (going to post in "When to replace ignition coils" thread too), but could NOT get the new springs to go in, and couldn't find anything on line about getting this style of spring to seat, so put the old spring back in (thankfully pretty easy).

[[ longer post was below, but removed since redundant ]]

 

[VTOLC100]

Today I changed the spark plugs out for OEM Denso. I'm not sure if they were ever done before.View attachment 3509585

I noticed there is quite a bit of buildup on the cylinder head. Any suggestion on what to do with that?
View attachment 3509586

Also, some coils are cracked, and some boots are brown vs gray. I read you can get the Denso boot kit. Does anyone have a reference to that?
View attachment 3509587

Would it be ok to put the cracked coils back in for a short period of time to drive for a week or so?
View attachment 3509588

 

[kevgentile]

Today I changed the spark plugs out for OEM Denso. I'm not sure if they were ever done before.View attachment 3509585

I noticed there is quite a bit of buildup on the cylinder head. Any suggestion on what to do with that?
View attachment 3509586

Also, some coils are cracked, and some boots are brown vs gray. I read you can get the Denso boot kit. Does anyone have a reference to that?
View attachment 3509587

Would it be ok to put the cracked coils back in for a short period of time to drive for a week or so?
View attachment 3509588

Cracked coils are fine until you start getting misfire faults

 

[KraziAzn]

Today I changed the spark plugs out for OEM Denso. I'm not sure if they were ever done before.View attachment 3509585

I noticed there is quite a bit of buildup on the cylinder head. Any suggestion on what to do with that?
View attachment 3509586

Also, some coils are cracked, and some boots are brown vs gray. I read you can get the Denso boot kit. Does anyone have a reference to that?
View attachment 3509587

Would it be ok to put the cracked coils back in for a short period of time to drive for a week or so?
View attachment 3509588

One of mine has been cracked for 2 years now. I swap it from Cylinder 7 to 1. This way it'll be easy to replace it when it goes bad. I keep a spare one in the car.

 

[shtbrwn86]

Is there a video on here of the spark plug tick so we can hear what it sounds like? I heard one online that sounded pretty severe. Just trying to get a feel for what to listen too. If it’s in this thread no need to link it. I’ll happily go through them all if it’s been posted.

Also, if I’m gonna pull the spark plugs (of unknown age/brand) to inspect the cylinders should I just throw new ones in just because I’m in there?

 

[flyingscot]

My tick comes from cracked exhaust manifold I think (not the plugs). If you are in there I would likely change the plugs, inspect the coils. Plugs - dry install (no copper etc) - 17 ft.lbs - worked a treat for me. Good luck.

 

[2001LC]

If you've a tick, tick, tick replace or at least check your spark plugs. If one blows out the head:

• It will be costly
• Will damage beyond use, The threads of head that holds in spark plug. It may damage: cylinder wall, piston, rings, valves or valve seat.
• You'll not be driving until repaired.

If you've no record of spark plugs replaced, replace them. It's a worthwhile PM.

You can just retighten. But replace, and your done for next ~90K miles or until tick, tick, tick. Spark plugs have a gasket (crush washer), which doesn't work as well (but does work) a second time.

You think tick, is blown exhaust gasket or crack exhaust manifold. Replace the spark plugs. If tick doesn't go away, then you've confirm exhaust leak. Exhaust leaks anywhere need to be taken care of. But they're less damaging if damaging at all. But, if you blow a spark plugs out the head, you'll regret it and kick-yourself. As you now know it is an issue!

No video sound file I know of, but search an likely find one. Most will likely be under heading; cracked exhaust manifold, what's this tick, what's this pop, strange sound on cold start, sound did once go away once engine warmed up but now doesn't, ticking sound as I drive by wall, etc.

Sound of loose spark plugs is easily heard:

• Place ear at/in front fender well, on one side than the other. tick tick tick. Mostly heard and loudest on cold engine start-up.
• Have someone driveaway, stepping (do not floor it) on gas as if in a hurry. pop. pop. pop.
• Drive close to/along a wall, like a brick building or concert HWY divider. tick tick tick.

Note: If you've a hole in your muffler, it may mask or be confused with the tick.

When replacing spark plugs:

1. Blow off top of engine and blow out spark plugs tubes, before removing spark plug. It is best to snug them down, before blowing out the tubes. We do not want dust (sand) dropping in cylinders, as spark plug removed or installed.
2. Replace spark plugs, using ones from a known good supplier. So many bootleg plugs in the market, which they too can be damaging. Buy cheap get cheap, but high price is no guarantee. I use Dense IK20TT. Because the China bootlegger's (last I saw), can not reproduce the ultra this .4mm electrodes. So I can spot them, by comparing with any other spark plug. The TT, also starts with a narrower gap of 1.0mm. The tighter the gap, the less AMPs required for spark, the less heat produced. Heat is the enemy, of the coil(s). Replacement is best, but not needed if gap has not increased by 0.1mm. Factory new spec 1.1mm gap, replace at 1.2mm<. The Denso TT start at 1.0mm, replace at 1.1mm. Checking gap is and art, done with a very very lite touch. If your a gorilla, do not even check or you'll damage the electrode. I use 0.01 or 0.02mm less thickness feeler gauge(s), so I don't put to much pressure on electrode. If gap wrong or electrode look misaligned. It's likely a junk plug, boot leg, a return that was damaged or packaging damaged. It is best to return those. Only experts can change gaps and alignment.
3. I torque to 18ft-lbf, which is 5ft-lbf above factory spec. I do this in "hopes", they hold longer before walking-out. But spec of 13ft-lbf is fine too, with new spark plugs.
4. I replace coil boots and top seal, while in there. Boot contain the spark form bouncing around inside tube and top seal keeps tubes clean. Torque coil bolt to 66INCH-lbf, gives proper sealing pressure to top seal.
5. I retorque head cover bolts to 53INCH-lbf, while there. This stops most (98%) all head cover oil weeps

Repeat every time tick heard or 90K miles (timing belt service) on average. Keep in mind; it's not miles driven. It's about how many heating and cooling cycles.

TICK TICK TICK goes the time bomb!

 

[94SRUNNER]

Decided it was time for a spot check on my plugs. All good @18ft-lbs and had driven ~6600 miles since I previous checked them in September 2022. Before that I had checked them August 2021 and had driven 6700 miles.

If nothing else, it is peace of mind.

Check your torque!

 

[dahlmaker]

I toasted a plug and threads are gone. I plan on using a time sert kit to fix. Anybody have a kit # they recommend to use? any tips for using this? I've never done a re-thread.

 

[SteveH]

I did a compression check 6 mo. ago and tightened all the plugs to spec. Had an ignition coil fail last week, replaced it, and saw that the spark plug appeared to be under-tightened (not the cause of the coil failure - that was due to age).

Today, I checked all 8, and 3 more were more-or-less finger tight. I tightened all to spec (and a little bit more). I heard no ticking sound, but clearly 4 of my 8 plugs were somewhat loose. Worth checking this from time to time.

 

[dahlmaker]

I toasted a plug and threads are gone. I plan on using a time sert kit to fix. Anybody have a kit # they recommend to use? any tips for using this? I've never done a re-thread.

According to Time Sert, here is the correct Time Sert for the Land Cruiser 100. I had ordered the wrong one from Amazon.

Time-Sert 4412E-111 M14 x 1.25 Deep Hole Metric Spark Plug Thread Repair Kit - https://www.mechanicstoolsandbits.com/time-sert-4412e-111-m14-x-1-25-deep-hole-metric-spark-plug-thread-repair-kit?search=4412E-111

 

[dace voit]

I did a compression check 6 mo. ago and tightened all the plugs to spec. Had an ignition coil fail last week, replaced it, and saw that the spark plug appeared to be under-tightened (not the cause of the coil failure - that was due to age).

Today, I checked all 8, and 3 more were more-or-less finger tight. I tightened all to spec (and a little bit more). I heard no ticking sound, but clearly 4 of my 8 plugs were somewhat loose. Worth checking this from time to time.

Did you install new plugs after the compression test? If not, then the torque spec is different, although not listed. I find that I have to use a bit more torque on already crushed plug washers because they've already been deformed. Ideally, they should be replaced. If the plugs were new, then ~18 ft/lbs is a better spec than the factory 13 ft/lbs. It's worked well for me and what appears to be others from this thread.