I would think every oil change but @2001LC would have better info. Been quite a bit since I read his very well pout together "ticking time bomb" thread
I'm Screwed???!!! Sparkplug Threads Melted
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Checking tightness every once in a while is good but the recommendation is also to use a higher torque setting when torquing down the plugs. Especially with used plugs / repeat plug installation. I believe factory spec is 13ft/lb but the recommendation is to go with 17-18ft/lb.
How often to checks spark plugs, depend on how many cold starts (warm up and cool down cycles). For most checking or replacing spark plugs, during Timing belt service, is perfect. Others, may want to check each 40K miles. Very best indicator is sound. TICK TICK TICK POP POP POP, just like exhaust manifold leak. Hear it, check the spark plugs.
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This has thread has me worried. My ‘04 has had a rattle since I’ve owned it (Oct ‘23) and I’ve always assumed it was the heat shields on the catalytic converters. It mostly happens at low RPM’s and when it’s cold out.
Time to pull the plugs and cross my fingers it’s not this tick tick pop pop being mentioned here.
Time to pull the plugs and cross my fingers it’s not this tick tick pop pop being mentioned here.
My ears aren't, that good. I actually don't hear it all that often. Because I change spark plugs very often, in baseline.
I suppose if one really in tune. You'll hear pop, tick, pop, tick, pop, tick (compression stroke pop, exhaust stroke tick) with loose spark plugs. Tick with only, exhaust leak only. Both pop, tick, tick.
But as I've stated. Sounds just like exhaust leak. Hear it, check the spark plugs.
@2001LC - I'm in Denver (Wash Park area) and was replacing the spark plugs on a 2UZ yesterday ('07 GX470). This one came out with the coil pack still stuck in the boot. Threads look stripped in that cylinder (thankfully #6 on the passenger side where there's plenty of room to work and not up against the firewall). Borescope is en route to confirm but I'm pretty sure I need to attempt a thread repair insert and am leaning Time-Sert 4412e-111. I'm willing to DIY it if I can't find anyone but would prefer an experienced shop (especially when it comes to making sure I don't drop any debris). Is this something I could hire you to do? Or do you know anyone near Denver that has done it before and could help me out? Even better if they already have the right kit/inserts on hand. Thanks!My ears aren't, that good. I actually don't hear it all that often. Because I change spark plugs very often, in baseline.
I suppose if one really in tune. You'll hear pop, tick, pop, tick, pop, tick (compression stroke pop, exhaust stroke tick) with loose spark plugs. Tick with only, exhaust leak only. Both pop, tick, tick.
But as I've stated. Sounds just like exhaust leak. Hear it, check the spark plugs.
First; I work on 100 series only!.
Those thread aren't as bad looking in pic. We usually see posted in the forum much worst. You may want to try chasing threads first. Add a good thick grease to chase, to hold debris. Then degrease threads and try a new plug. If it holds 18ft-lbf dry (no lube on threads) great. If not, you just loose a little time.
Those thread aren't as bad looking in pic. We usually see posted in the forum much worst. You may want to try chasing threads first. Add a good thick grease to chase, to hold debris. Then degrease threads and try a new plug. If it holds 18ft-lbf dry (no lube on threads) great. If not, you just loose a little time.
Was there ever a TSB from Toyota on this?
Pics aren't great but it does seem like there's a decent amount of thread left. I ordered an M14 back tap to try and chase them from underneath.
Also vacuumed all that crud out of there using a spare piece of vacuum tubing poked through a rubber pipe cap and clamped to the end of my shop vac. I'll keep you posted!
To me that looks more like corrosion (oxidized aluminum) on the spark plug threads. as opposed to actual aluminum. Usually when a steel or other metal bolts stirps in aluminum, there will be little strips of aluminum in the bolt threads themselves. I suspect it will hold the OEM torque spec with no problem.
Note: a "chase", cleans threads. Whereas a tap cuts threads. Tap could make threads loose.
I "think" it's is a 14Mx 1.25, make sure to check with a spark plug. But note, there are different types of thread. Depth, angle, etc..
Looking at new pic of port. I'd just chemically clean and try new plug. I'd use BG throttle body cleaner soaked lent free rag attached to end of wire coat hanger. I may use a BG or CRC throttle body cleaner soaked nylon bush.
I "think" it's is a 14Mx 1.25, make sure to check with a spark plug. But note, there are different types of thread. Depth, angle, etc..
Looking at new pic of port. I'd just chemically clean and try new plug. I'd use BG throttle body cleaner soaked lent free rag attached to end of wire coat hanger. I may use a BG or CRC throttle body cleaner soaked nylon bush.
Yep confirmed M14 with a 1.25mm pitch.
Despite being literally called a back "tap" it's just a thread repair tool (chaser) that can't actually cut threads. The advantage is that it works from below so the crud is less likely to fall down into the cylinder. I watched my uncle use one on a Ford many years ago.
Good idea on the throttle body cleaner - I'll try that first.
I can't find any imagery on the net right this instant. But Google is telling me that Duralast DOES NOT use a "D" to mark their stuff and Denso DOES.
It has been so long since I have even allowed anything from Duralast in the shop that I can't snap any pics for you.
Mark...
It has been so long since I have even allowed anything from Duralast in the shop that I can't snap any pics for you.
Mark...
Great, yet another tool I don't have...
I have to disagree with this as I unfortunately had to purchase one coil from autozone at one time and it had the large “D” for Duralast stamped on it. Much larger than the coil on first page of this thread. None of the denso coils I currently have installed are like thatI can't find any imagery on the net right this instant. But Google is telling me that Duralast DOES NOT use a "D" to mark their stuff and Denso DOES.
It has been so long since I have even allowed anything from Duralast in the shop that I can't snap any pics for you.
Mark...
Hopefully I'll never need this tool again (or at least not for another 80k miles)! You're welcome to have it if you're ever down here around Wash Park. Though I should probably check the threads on the '05 4runner before I give it away
I cleaned the #6 threads a bunch last night with TB cleaner and a microfiber rag + clothes hanger but still can't get the new spark plug to engage and catch the threads.
I suspect the plug had been walking itself out for some time and likely boogered up the uppermost threads (either from rattling around over time or maybe was partially out and not fully engaged when it finally blew out completely, sparing the bottom threads). I'm of course hesitant to put any force into the new plug try to get the threads to catch so I think the back tap will be my next step. I'll probably try to thread in the plug one last time (maybe with a tiny dab of wd40 on the bottom most thread?) and potentially one last scrub with a nylon brush this time before I fully commit.
The other advantage of the back tap is that, starting from the bottom, it should engage with the good lower threads and be nicely aligned by the time it gets to what I suspect are the problematic threads up top. I'll let you know how it goes!
Further evidence that the top threads in #6 are likely bad is that the adjacent cylinder (#4) looked even nastier (picture below) but that plug catches and torques down just fine even though you can feel some grit. After scoping, I cleaned that one out with TB cleaner too and now it looks much better and went back in smoother.
