Lexus LX470 sputtering (1 Viewer)

[dbleon]

You should have blown the tube clean with compressed air before loosening or removing the plug.

I would be very cautious trying to chase a spark plug hole because you could get metal into the combustion chamber (bad).

You might want to try and thread in a new plug without going any further to see if it will thread. If not, you should take it to a mechanic to evaluate further

If you’re set on trying the chase, make sure it’s greased and do like 1/2 turn at a time then remove and clean chase and re-grease

 

[kevgentile]

So, the spark plug that came out did not pull the threads out from the head, and the threads on that plug were only messed up a little bit. Do y'all think cleaning the existing threads up with a tool like this would be better than putting in an insert?

https://www.autozone.com/test-scan-and-specialty-tools/thread-repair/p/duralast-m14-x-1-25-thread-chaser/1266635_0_0?spps.s=495&cmpid=LIA:US:EN:AD:NL:1000000:TLS:19489353547&CATARGETID=120054150001289970&CADevice=c&gad_source=1&gclsrc=ds

If the threads are there just clean with a chaser and install the new plugs with some anti-seize.

 

[2001LC]

I doubt threads will hold a new spark plug. But certainly worth inspect & testing threads.

Not attacking the OP here. I feel your pain.
I so hate seeing this needless condition, of spark plugs blowing out the head. I've beat the drum on the "tick" for years.
"Hear a cold start tick. Replace the Sparks Plug. Hear it even after warm-up, do not run engine."

Tick can be the common Exhaust Manifold (EM) leak. It can be even both EM & spark plug. But I've yet to see exhaust manifold leak cause damage. So hear it change the spark plug or tighten then at minimum.

You can 99.9% count-on, threads in head are damaged. If I'm correct, you've choices:

1. Scope cylinder. Looking for signs of damage. It's helpful to scope all, to get a baseline/comparison. This well help determine, procedure to fix and how many $$ worth spending..
2. If cylinder found damage, use a Time-cert. Install with the greatest care, not to drop in metal shavings. The engines' not that great anyway, so roll the disc. This is fast and cheap.
3. Great engine, you want to make sure stays that way. Pull the head, to install Time-cert or replace head. Labor time and parts cost considerable more.

Great engine:
I've one engine in my 2003LX with 315K miles on it. It may be the the best 4,7L 2UZ I've had in ~20 years. It's compression and MPG are both unbelievably good. I'd pull it's head to repair.

Good or not so good, engine clues/inspection:
Cylinders look (scope) good, in a well care for engine. i.e. good filters and oil service history. No vacuum leaks (sucking dust). No excessive dust in air filter tube, which would indication sucking dust. Starter never replaced. If replace, it's known, that mechanic took the extra time to clean before removing intake manifold.

Engine compression was tested, and was great. Not likely in OP case. Since, SP should have been re-torque at that time.