Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert! (1 Viewer)

[SlowBuild]

I came across this video a while back. This guy ran his own test of all the different types of thread inserts with Time-Sert failing at lower pullout force vs helicoil.

Hmmmm…. Interesting. That seems to contradict consensus but I have no experience myself. My mechanic is pretty sure he’ll have to pull the head to do a Helicoil but is willing to try the Time-Sert with it still on the block. To me the difference in labor is worth to give it a shot. I may feel differently down the road. I’ll be sure to post here if it fails and to I follow up my experience.

Anyone else want to talk me out of a Time-Sert? I’m not 100% sold yet and I have two more days to decide.

 

[flintknapper]

Hmmmm…. Interesting. That seems to contradict consensus but I have no experience myself. My mechanic is pretty sure he’ll have to pull the head to do a Helicoil but is willing to try the Time-Sert with it still on the block. To me the difference in labor is worth to give it a shot. I may feel differently down the road. I’ll be sure to post here if it fails and to I follow up my experience.

Anyone else want to talk me out of a Time-Sert? I’m not 100% sold yet and I have two more days to decide.

I'm in the Time-Sert camp.

 

[divejoe]

I just did my plugs at 102k mi, partially in response to @2001LC 's extensive reporting on this.

- 2 plugs on the driver's side were leaking a little gas (browning of the boot, slight staining of the aluminum around the coil seal)
- all plug threads were slightly rust-colored (gas staining I assume)
- all were at or under 10 ft-lbs to unscrew, the front driver's side plug was hand-loose
- existing dual-tip plugs had the top tip almost worn away in most cases
- I replaced with IK20TT Denso's from AutoZone (in green 4x packs, with plastic protectors)
- I put them in with 180 in-lbs of torque, NO ANTISEIZE, after "snugging" with a regular 3/8" drive ratchet

What an easy plug job! Thanks for the tips on the plastic plug removal. For the driver's rear, I just used a 3"+1.5" extension, then my Snap-on impact swivel and then a 12" extension. Easy. People complaining about this plug job need to try a 1st-gen Xterra plug #6 (dealerships notoriously skip that plug).

Just did mine before reading this and I put anti-seize on the plugs...dang it! Will have to replace them again, glad that it was an easy job.

 

[flyingscot]

Thx everybody - a great thread

For completeness I just changed out my plugs for DENSO SK20R11s - longlife Iridium (amazon).

Of particular note:
- Job was initiated after a misfire on #8 (failed coil)
- Installed plugs were all reasonably tight except #8 and were in good condition - also SK20R11
- Recovered plug #8 - this plug was not fully engaged in the cylinder head
- Reinstalled all the plugs with 15ft.lbs torque - with no anti-seize (best practice after reviewing this thread)
- #7 & #8 - I could not get the torque wrench to them but by then had developed the 'feel' of the crush washer & additional (approx 1/4 turn) so am confident torque is good
- Replaced all of the coils with DENSO 6731303 (Amazon)
- On start up the previous engine header 'tick' had been eliminated (suspect that was plug #8 bypass)
- Vehicle running much better (smoother) & all codes eliminated

 

[94SRUNNER]

It has been about 6.5 months and 5400 miles since I install new coil packs and torqued the plugs to 17ft-lbs and I had some time this morning. Thankfully all 8 plugs were still snug at 17ft-lbs.

 

[Roosevelt T]

Hey guys - just to bump this with an anecdotal story that happened to me.

Drove the truck back and forth across the country - from AZ to NY and back. On the second to last night of the trip I pulled up to my hotel in OKC and heard a knocking sound from the engine - that isn't good. I know these engines basically do not blow, so I was a little confused but obviously concerned. On closer inspection I saw the coil pack for cylinder #5 pulsating. I pulled the coil pack and the plug wasnt even hand tight - obviously it had loosened. The next morning I went and chased the threads about 20 times, but I couldnt get the plug to thread in more than 2 turns. I unplugged the injector, removed the coil pack and drove the last 950 miles on 7 cylinders. I tightened all the other plugs - I dont think any were to torque spec.

Got home and did the time sert yesterday and replaced all the spark plugs. They were all SK20R11's from the previous owner. He was a member here and I have found very few things he didnt do well while wrenching on it - I dont think this is his fault. I just think they loosened over time. Checking all the coil packs and plugs was on my list for this winter - wish I had checked them sooner.

 

[flyingscot]

Thx everybody - a great thread

For completeness I just changed out my plugs for DENSO SK20R11s - longlife Iridium (amazon).

Of particular note:
- Job was initiated after a misfire on #8 (failed coil)
- Installed plugs were all reasonably tight except #8 and were in good condition - also SK20R11
- Recovered plug #8 - this plug was not fully engaged in the cylinder head
- Reinstalled all the plugs with 15ft.lbs torque - with no anti-seize (best practice after reviewing this thread)
- #7 & #8 - I could not get the torque wrench to them but by then had developed the 'feel' of the crush washer & additional (approx 1/4 turn) so am confident torque is good
- Replaced all of the coils with DENSO 6731303 (Amazon)
- On start up the previous engine header 'tick' had been eliminated (suspect that was plug #8 bypass)
- Vehicle running much better (smoother) & all codes eliminated

after 3k miles - checked LH bank of cylinders - 2/4/6/8 - all plugs tight - however set torque wrench to 17ftibs and snugged them up slightly, from previous 15 ftlbs. Will do same with RH bank in due course.

 

[94SRUNNER]

after 3k miles - checked LH bank of cylinders - 2/4/6/8 - all plugs tight - however set torque wrench to 17ftibs and snugged them up slightly, from previous 15 ftlbs. Will do same with RH bank in due course.

I think based on the 2UZ history it is a good habit to get into to of checking the torque at least annually. I have been doing it about every 6 months since last year after finding a few plugs that were on the loose side.

 

[thebeedeegee]

Hey guys - just to bump this with an anecdotal story that happened to me.

Drove the truck back and forth across the country - from AZ to NY and back. On the second to last night of the trip I pulled up to my hotel in OKC and heard a knocking sound from the engine - that isn't good. I know these engines basically do not blow, so I was a little confused but obviously concerned. On closer inspection I saw the coil pack for cylinder #5 pulsating. I pulled the coil pack and the plug wasnt even hand tight - obviously it had loosened. The next morning I went and chased the threads about 20 times, but I couldnt get the plug to thread in more than 2 turns. I unplugged the injector, removed the coil pack and drove the last 950 miles on 7 cylinders. I tightened all the other plugs - I dont think any were to torque spec.

Got home and did the time sert yesterday and replaced all the spark plugs. They were all SK20R11's from the previous owner. He was a member here and I have found very few things he didnt do well while wrenching on it - I dont think this is his fault. I just think they loosened over time. Checking all the coil packs and plugs was on my list for this winter - wish I had checked them sooner.

How well did it run on 7 cylinders? Just curious for future reference. I know I've read about people driving a long way on a failed/failing coil pack. In the case of a failed coil would it be better to just unplug the injector and coil as you did if you have a long way to go?

Also, how did you keep debris out of the cylinder when you were chasing the threads?

 

[Roosevelt T]

How well did it run on 7 cylinders? Just curious for future reference. I know I've read about people driving a long way on a failed/failing coil pack. In the case of a failed coil would it be better to just unplug the injector and coil as you did if you have a long way to go?

Also, how did you keep debris out of the cylinder when you were chasing the threads?

It ran fine, albeit down on power (obviously, haha). I cannot say which would be better - tbh i would have kept the coil in if possible - but i tried chasing the threads to install a new one and I still couldnt get it to thread. Unless I was 100% sure I had it seated perfectly I probably would have driven home on 7 cylinders regardless.

I didnt worry about debris in the cylinder head... it's not that it didn't cross my mind - but the odds seemed tiny and my buddy who is a mechanic said it wasnt anything to worry about.

 

[2001LC]

I disagree with concern of debris getting into cylinders. This is always a concern! Practice is to grease repair tool when working on spark plug threads. The idea is; the grease will capture the debris (metal).

But in the few cases I've checked compression, where time cert was installed. Compression was lower (out of spec) than other cylinders.

Even changing spark plugs, where coils top seal is shrunken, damaged or missing. We get debris (sand) into spark plug tube. Than as we replace plugs, debris falls in cylinder. This too can damage cylinder walls, and in most cases reduce compression.

Other events that damage cylinder wall(s) & rings:
Improper or poor air filtration, which includes and vacuum leaks sucking in dust.
Not cleaning top of engine before pulling intake manifold. Dropping debris into intake ports of heads.
Improper oil & filter change interval.

They still run okay in most cases, with low compression. It's a 2UZ after all, and they just keep ticking! Provided not severely overheat or run without oil.

 

[Mike NXP]

I disagree with concern of debris getting into cylinders. This is always a concern! Practice is to grease repair tool when working on spark plug threads. The idea is; the grease will capture the debris (metal).

But in the few cases I've checked compression, where time cert was installed. Compression was lower (out of spec) than other cylinders.

Even changing spark plugs, where coils top seal is shrunken, damaged or missing. We get debris (sand) into spark plug tube. Than as we replace plugs, debris falls in cylinder. This too can damage cylinder walls, and in most cases reduce compression.

Other events that damage cylinder wall(s) & rings:
Improper or poor air filtration, which includes and vacuum leaks sucking in dust.
Not cleaning top of engine before pulling intake manifold. Dropping debris into intake ports of heads.
Improper oil & filter change interval.

They still run okay in most cases, with low compression. It's a 2UZ after all, and they just keep ticking! Provided not severely overheat or run without oil.

Any shortcuts for a quick check of the spark plug torque? Of course best practice is to remove the coil and inspect but what about for a quick check between maintenance? For example, do you think if they were backing out would you feel this by touching the coil? I thought I saw another member mention that.

 

[2001LC]

No test other than sound, I know of. Tick during cold start-up, is getting very loose. If still ticking after warm up, ready to blow out head.

Best practice is:
1) If unknown when or if spark plugs replaced. Replaced them! One could say replace at 90K miles. But even a 30k or 60K mile, one could have loose plugs. As it's more about heat and cooling cycles than miles.

2) Replace with every timing belt job (7 yrs or 90K miles.)

 

[MountaineerLC]

Asking a cheapskate question here....

Must iridium spark plugs be used or can a less expensive platinum spark plugs be used? Just as an example, the local Napa has NGK platinum plugs with the proper gap for less than half the price of the NGK iridium plugs. Of course I do realize that iridium plugs have a longer service life and that prices somewhat even out when you consider that.

 

[cwmoser]

I checked all my Spark Plugs for torque in my 2002 LX470. All were in there good and tight - still factory plugs but only 60K miles.
Was a little paranoid when we blew out a spark plug in our 2004 Land Cruiser.

 

[Mike NXP]

No test other than sound, I know of. Tick during cold start-up, is getting very loose. If still ticking after warm up, ready to blow out head.

Best practice is:
1) If unknown when or if spark plugs replaced. Replaced them! One could say replace at 90K miles. But even a 30k or 60K mile, one could have loose plugs. As it's more about heat and cooling cycles than miles.

2) Replace with every timing belt job (7 yrs or 90K miles.)

Thanks for the heads up. Mine were swapped recently but unfortunately not by my hand. I'll have to check them when it's not so cold out, sounds like a spring time job since she is sounding pretty smooth currently.

 

[Roosevelt T]

I disagree with concern of debris getting into cylinders. This is always a concern! Practice is to grease repair tool when working on spark plug threads. The idea is; the grease will capture the debris (metal).

But in the few cases I've checked compression, where time cert was installed. Compression was lower (out of spec) than other cylinders.

Even changing spark plugs, where coils top seal is shrunken, damaged or missing. We get debris (sand) into spark plug tube. Than as we replace plugs, debris falls in cylinder. This too can damage cylinder walls, and in most cases reduce compression.

Other events that damage cylinder wall(s) & rings:
Improper or poor air filtration, which includes and vacuum leaks sucking in dust.
Not cleaning top of engine before pulling intake manifold. Dropping debris into intake ports of heads.
Improper oil & filter change interval.

They still run okay in most cases, with low compression. It's a 2UZ after all, and they just keep ticking! Provided not severely overheat or run without oil.

I misread the question, my apologies. I was reading it quickly and for some reason thought he was asking about the uncovered cylinder while driving.

I greased the s*** out of the spark plug thread chaser when chasing the threads, and my mechanic greased the s*** out of the tap when installing the time-sert. Definitely use a good amount of grease and re-grease when necessary to ensure that nothing falls into the cylinder.... this will be more necessary when installing the time-sert. I think we got rid of the shavings and re-greased 3 or 4 times... just use common sense and its not too bad, haha.

 

[krispykritter]

@2001LC and the rest of you who commented lately - thanks for bringing this thread to the top. For whatever reason, and despite this being part of my normal baselining on every vehicle I buy, I never changed the plugs on the LX when I bought it. I recently realized this and ordered some new plugs to replace the old ones whenever I had some free time but wasn't in a rush....until I saw this thread and figured might as well knock it out.

Wanna guess which ones were loose/leaking?

In my case, the bad ones were cylinders 3 and 7. The coil boots also looked nasty and had soot on them but no major damage. Glad you guys accidently got me off my butt and got these replaced on my lunch break today! Thanks again.

 

[ToyotaBrah]

Bumping this thread for those who haven't seen it yet.

I remembered this thread while replacing the valve cover gaskets and just about all mine were noticeably loose.

 

[94SRUNNER]

Bumping this thread for those who haven't seen it yet.

I remembered this thread while replacing the valve cover gaskets and just about all mine were noticeably loose.

Good catch!