I'm Screwed???!!! Sparkplug Threads Melted

[dahlmaker]

After getting a misfire code on number 4 and 8 I thought it was just a coil. I drove it another mile home and pulled #4 and after removing the bolt the coil and plug all came out together. #8 looked fine, but as you can see #4 is FUBAR.

I tried screwing in another plug and threads in the head are gone.

My truck is 1999 with 220K on it. I change oil, filters, fluids on schedule. I heard a slight ticking about a week before this happened and did a quick scan under the hood, but didn't notice anything. #4 is behind the air box, so maybe if I pulled that I would have seen/heard an exhaust leak.

So has anyone else had this happen??? My questions.

1. Why? I didn't install the plugs, maybe they weren't tight which caused the leak? The bolt on the coil was tight.
2. Anybody ever rethread?
3. So time for new heads or a new 4.7?

Hope everyone is having a better Sunday than me.

 

[SmoothLC]

See @2001LC's Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert! thread.

 

[dahlmaker]

See @2001LC's Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert! thread.

Thanks! I'm going to try a time sert rethread first.

 

[GTV]

OEM coils or aftermarket?

 

[dahlmaker]

D for Denso?

 

[dahlmaker]

OEM coils or aftermarket?

Looks like Duralast

 

[2001LC]

Reports of spark plug blowouts, due to walking out. Are on the raise!

How can we get the word out, to more 4.7L owners and shops!

 

[Rednexus]

Reports of spark plug blowouts, due to walking out. Are on the raise!

How can we get the word out, to more 4.7L owners and shops!

Are you seeing this on just the 100s or other 4.7-equipped 4Runners, Tundras, GXs, etc? I don't see why it would be any different but this issue has not been reported on the other forums to my knowledge. I'm gonna check mine today when I change the oil.

 

[2001LC]

Are you seeing this on just the 100s or other 4.7-equipped 4Runners, Tundras, GXs, etc? I don't see why it would be any different but this issue has not been reported on the other forums to my knowledge. I'm gonna check mine today when I change the oil.

IMHO: ALL 4.7L 2UZ-fe are at risk of spark plugs walking out. In all makes and models!

I only deal with 100 & 200 series, and I only read/post in ih8mud. But I see no reason why, all wouldn't be at risk. The 4.7L heads, are all the same. Even in the 4.7L 2UZ-fe VVT.

You've posted in a number of threads in last few days on this. So I assume you've now read at least the OP on my alert.

You heard the sound but didn't know, as many don't.
All 4.7L sound off clearly, the warning sound TICK TICK TICK or POP POP POP.
Warning sound is first heard, during cold start-up.
One only need put their ear to fender well, TICK TICK TICK. Cold engine start TICK is early warning. If heard after warm-up, stop engine and check spark plugs.
POP POP POP, is head. By someone standing at the curb, as vehicle driven off with a heavy foot on gas pedal. If after warm-up, shut it down.

 

[Rednexus]

IMHO: ALL 4.7L 2UZ-fe are at risk of spark plugs walking out. In all makes and models!

I only deal with 100 & 200 series, and I only read/post in ih8mud. But I see no reason why, all wouldn't be at risk. The 4.7L heads, are all the same. Even in the 4.7L 2UZ-fe VVT.

You've posted in a number of threads in last few days on this. So I assume you've now read at least the OP on my alert.

You heard the sound but didn't know, as many don't.
All 4.7L sound off clearly, the warning sound TICK TICK TICK or POP POP POP.
Warning sound is first heard, during cold start-up.
One only need put their ear to fender well, TICK TICK TICK. Cold engine start TICK is early warning. If heard after warm-up, stop engine and check spark plugs.
POP POP POP, is head. By someone standing at the curb, as vehicle driven off with a heavy foot on gas pedal. If after warm-up, shut it down.

I've posted because it's such a concerning failure mode . I have read your thread as well and it's very good info. Mine definitely does NOT have any kind of start-up ticking and is whisper quiet. It is pretty easy to pull the coils and check plug torque - so I'll do that and see if they are loose or not. The plugs were in good shape when I bought the rig 40K ago; guessing they were replaced between ~100-135K so they have ~40-75K on them now.

EDIT: Looks like it's definitely a "thing" with the 1st gen Tundra's, but I've found only one report on a GX/4th gen T4R. Interesting as didn't they come out of the same plant in Japan? Still need to check mine....hard to make it out to the shop when it's 2F out.

 

[Bomar]

His is also an aftermarket coil burning too hot...

 

[GerLC100]

Have the car less than a week but already got a cylinder 1 missfire
Swapped that cylinder to OEM plug and NGK coil from Napa (just like the company ^^)

 

[dahlmaker]

I'm going with Time sert. The plug measures 15mm length and this looks like the correct kit. Can anyone confirm?

M10x1.0 Spark plug Extended P/n 4010EXT-133​

M14x1.25 Spark Plug Extended Kit Washer seat P/n 4412E-111

For first time repairs. M14x1.25 spark plug extended Washer Seat kit. See specifications tab:

time-serts.com

 

[2001LC]

I can't not confirm. But I do know, there're a few different markers of kits. Some have kit's very specific for aluminum heads.

I'd first get out my borescope. Making sure cylinder, piston and valves okay.

 

[hoser]

His is also an aftermarket coil burning too hot...

I'm guess that is a result of the spark plug walking out... heat blowing by the threads.

 

[cwmoser]

My son's 2004 LC blew a Spark Plug. A TimeSert fixed her up.

 

[GTV]

His is also an aftermarket coil burning too hot...

I don’t have data to back it up but it seems to be more common with aftermarket coils. I just ordered a set of Denso coils & plugs from RockAuto for my Tundra to hopefully avoid this scenario.

 

[zoomzoom913]

@dahlmaker how did this turn out for you? I have nearly the same exact situation. I'm going to try an M14 thread chaser first because I did an endoscope and they didn't look too bad except the top. If that doesn't work I'll try the timesert. I would love to know how it turned out for you though.

 

[dahlmaker]

@dahlmaker how did this turn out for you? I have nearly the same exact situation. I'm going to try an M14 thread chaser first because I did an endoscope and they didn't look too bad except the top. If that doesn't work I'll try the timesert. I would love to know how it turned out for you though.

I did the Timesert and it's been good as new. What a feeling to hear it fire up again with no codes or weird sounds, just back to the steady purring of the 4.7.

It's been a year now. All good. Timesert did recommend a different product than the one I may have linked. Here's the one they recommended and that I purchased for the 4.7. Good luck!
Time-Sert 4412E-111 M14 x 1.25 Deep Hole Metric Spark Plug Thread Repair Kit - Mechanics Tools & Bits - https://www.mechanicstoolsandbits.com/time-sert-4412e-111-m14-x-1-25-deep-hole-metric-spark-plug-thread-repair-kit?search=4412E-111

 

[excessive]

how often should we be checking our spark plugs for tightness ? is that the only prevention ?