Frozen Spark Plug Removal on a 5.7 with 350,000 miles (1 Viewer)

[Craig Haworth]

Just curious if this is an issue anyone has experienced on these Toyota/Lexus LC 200/LX 570 5.7s? We have an 08 LC 200 with 350K on the clock, and may very well need to replace the ignition coils and spark plugs due to a recent P 0358 OBD2 Code. When I discussed bringing it in for a proper " analysis ", with an independent " specialist ", and after telling him the plugs had never been replaced during our ownership of over 270,000 miles, he said he wouldn.t work on it because of the risk the plugs are frozen from carbon build up.....so I thought I should put this on the forum to see what LC Enthusiasts think of his comment.

I can see where this could be an issue in some engines, where the threaded portion of the spark plugs actually extend into the combustion chambers, where carbon buildup could occur, but I am also aware some combustion chamber configurations are designed where there are minimal or no spark plug threads exposed...where carbon buildup cant occur. I actually remember "shimming" spark plugs on a blown and injected 426 Hemi I had in a flat bottom K boat, with the heads on a bench, so we could actually clock the electrode to " direct its spark" into the combustion chamber flow pattern....with no exposed threads....

Thoughts?

 

[willstroo]

Be interested to see if anyone can shed light on this. 350km is a great run on the car!

 

[DallasTide]

That's 560km

 

[Fisher23]

The specialist is correct. I could be an easy job with a pre-soak, or difficult using an extractor, or a nightmare that would involve removing the head.

 

[pvchaitanya]

This is risky, I dont have experience of sparkplug on high mileage never replaced LC but I did replace sparkplugs on a 200k miles (1st time plugs) on mercury sable with Iron engine block I think. Using a lot of freeze off liquid and other penetrating oils and slow back and forth, I was able to do the job but one just broke off half with the threaded metal piece still stuck to the engine block. I towed it to a shop where the guy said he can't work on it. Finally I found some tools on amazon where you would tap it in with reverse threads and hammer it and slowly turn it little by little.
Im telling you all of this so you can expect easy job since it aluminium block ,it may not rust or degrade as much as mine, but worst case scenario, you will be on your own trying to extract a broken sparkplug. Another tip, try to start the job when the engine is hot by spraying the penetrating oil or freeze off oil into the sparkplug wells so it penetrates well. Let it sit for long time and try tightening a little bit and back off. Slow is the key and applying too much force will snap off.

Some have reported running seafoam in engine oil and run the engine and put a little bit of seafoam into the sparkplug wells and try the job.

 

[CanadianRockyCruiser]

If they weren't overtorqued, I expect you will get them all out. But all of the heating and cooling cycles create an obvious concern.

I would replace them with tender love and care by myself. It's an easy job, as long as one doesn't get broken.

I think the factory torque is only ~13 ft lbs. One strategy would be to attempt to remove each plug using a torque wrench set to 20 ft lbs (in reverse/counter clock wise configuration). If you click the 20 ft lbs, then at least you will know how much force you are using. If it's insufficient, add a few ft lbs. The goal here is to avoid exerting too much force, and having a broken plug, of course.

I am probably stating the obvious here...

 

[bj70bc]

prob do it while its warm would be better id think

 

[stellite]

I've never gone that many miles without changing plugs so have no idea how bad it is. I did the plugs on my 250k mile sequoia, and I ran the engine for a while so it was hot and sprayed some freez off . The plugs came off easy. Same on my kids 200k mile Rav4. If you do it cold or warm, they may strip threads on an aluminum head or beak the plug.

 

[04UZJ100]

You will be fine

 

[Craig Haworth]

This is risky, I dont have experience of sparkplug on high mileage never replaced LC but I did replace sparkplugs on a 200k miles (1st time plugs) on mercury sable with Iron engine block I think. Using a lot of freeze off liquid and other penetrating oils and slow back and forth, I was able to do the job but one just broke off half with the threaded metal piece still stuck to the engine block. I towed it to a shop where the guy said he can't work on it. Finally I found some tools on amazon where you would tap it in with reverse threads and hammer it and slowly turn it little by little.
Im telling you all of this so you can expect easy job since it aluminium block ,it may not rust or degrade as much as mine, but worst case scenario, you will be on your own trying to extract a broken sparkplug. Another tip, try to start the job when the engine is hot by spraying the penetrating oil or freeze off oil into the sparkplug wells so it penetrates well. Let it sit for long time and try tightening a little bit and back off. Slow is the key and applying too much force will snap off.

Some have reported running seafoam in engine oil and run the engine and put a little bit of seafoam into the sparkplug wells and try the job.

Here’s an update! I managed to remove the 4 plugs and coils on the passenger side tonight, and all spark plug “wells” were rather oil soaked, caused it appears from 4 leaking rubber seals between the cam cover and coils.

I will say the plugs were not that tight, but # 6 and especially # 8 were a bit concerning during the extraction, so I took my time and went back and forth even on #8, where I got them all out un scathed! I’m 50% there.

Seeing how much oil was in the spark plug wells may explain the P 0358 code for IGN coil “H” (cylinder # 8 I presume)…

Planning to extract the other 4 tomorrow, and if that goes good, I will replace all of the coils, spark plugs and rubber seals. Thinking it might be a good idea to place a little Permatex high temp sealant on the back side of the new rubber seals, once the cam covers are degreased, to prevent more oil from leaking into the wells again…and causing an issue with the new coils.

Looking at everything, I feel this should prove to be worthwhile, and now I’m wondering about the injectors, because they are original as well!

Thoughts?

 

[TimCFJ40]

Glad you got half way there. I replaced my plugs at about 260k miles and I’m pretty sure it was the first time ever based on the plug wear. Absolutely no issues and as you experienced, they weren’t even that tight. I suspect you’ll have no issue with the other 4.

 

[Bisonthecruiser]

You've owned the car for 270,000 miles and never pulled the plugs? I know that's what you said, I'm just astonished...

 

[Craig Haworth]

I believe the biggest reason this went Ok was the fact these are high quality aluminum heads. The fact the spark plug wells were also full of oil didn’t hurt either?

If these were Iron heads, I don’t think I would be in such a great mood right about now…

These LC and LX 5,7s are beasts, and I would love to rebuild one someday, but it would cost a fortune…. so it’s a blessing they will probably outlast me!

 

[Craig Haworth]

Glad you got half way there. I replaced my plugs at about 260k miles and I’m pretty sure it was the first time ever based on the plug wear. Absolutely no issues and as you experienced, they weren’t even that tight. I suspect you’ll have no issue with the other 4.

I’m hoping that’s the case, but will take it slow still… At 350 K, I am optimistic still this will prove worthwhile, and get us more miles on the clock!

I had planned on keeping it until it had 500k, and we might make it mechanically, but the heat here in Florida really takes its toll on other things like plastic, so those are the things that might not allow us to get there!

Pulled a door panel off recently to look at the regulator, and some of the plastic tabs on the door panel broke easily as well as the door lock cables that were in plastic cable shrouds, all because of heat cycles for too many years!

Those are the things that concern me more than the mechanicals……

Still amazing vehicles, and worth repairing!

 

[doru]

EDIT: looks like we cross posted. Glad you figured it out. Congrats in those many miles but keep up with the maintenance if you're trying to get to those 500k.

------
ORIGINAL:
In the past I found his method useful

My worst case of steel to aluminum corrosion was on an aluminum subframe holding the bushings for sway bars. The steel bolts go through 2" of solid aluminum. Add salt, humidity and time, and you get a nightmare. The bolts were frozen solid to the aluminum on their entire length. No chance to torque them. The space there under the car is little, so a drilling out solution would have required lowering the subframe - a very labor-intensive proposition for the rear subframe on an AWD car. The subframe was huge and damaging it would have been a very expensive and labor-intensive mistake to fix. Solution was this BB2X-ACC Original Heat Induction Tool https://www.amazon.com/gp/product/B00ATSL7VE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 . It worked magic, no BS. The immense but very localized heat transformed the oxidation binding the two parts into fine white powder. I do not know if you have space for the coil to get inside the spark plug hole (there are different length and thickness induction loops).

Some have reported running seafoam in engine oil and run the engine and put a little bit of seafoam into the sparkplug wells and try the job.

Seafoam in engine oil does nothing (per OilGeek specialist). It will quickly evaporate when running the engine. Used as a thread lubricant in the spark plug hole may add some value as a cleaner but that may not be a good thing either.

You have two competing needs: 1. soaking the deposits to free up the threads that extend out into the combustion chamber, 2. lubricating the plug threads to prevent galling and damage to them. I do not know how effective the seafoam is against carbon deposits, and I do not know if I want to risk galling and damaging the threads in the head. I would play it much safer and use PB Blaster or equivalent.

About the shop, what is his worry, that you are not going to pay for the job if it gets nasty and require removal of the head or that he'll have one of his bays blocked for a few days until the head comes back from the machine shop? I do get that there is risk but as long as you both are on the same page with a prior agreement it should be fine, unless they just don't want to bother.

 

[TimCFJ40]

These had ~262k on them. Take a close look at the tips of the electrodes, almost totally worn away. All ran fine too until the # 1 ignition coil went out and I finally pulled the plugs…. Also you can tell from these that none of the threads protrude into the combustion chamber.

 

[CanadianRockyCruiser]

...

 

[CanadianRockyCruiser]

View attachment 3735377These had ~262k on them. Take a close look at the tips of the electrodes, almost totally worn away. All ran fine too until the # 1 ignition coil went out and I finally pulled the plugs…. Also you can tell from these that none of the threads protrude into the combustion chamber.

Yeah, those look fully depreciated.

 

[bj70bc]

but toyota said those were lifetime plugs

 

[Craig Haworth]

Yeah, those look fully depreciated.

So how many other Heavy SUVs with V8s do you think would survive 270k miles without changing the plugs??

I guess my other question is why change them at 100k . I changed plugs in a lot of my cars when I was young and didn’t know better, but I enjoyed it!! I also rebuilt most of my cars engines when I was young too, and my dad always asked me why I did it…. But in time, he realized I simply loved building motors and improving them, and for $1500, I could fully build, balance and upgrade a 454 LS 6 , so it was inexpensive to do, and there was nothing like a balanced 440HP LS 6 in a 70 Chevelle with 4:56 gears……

Now I appreciate Japan Built LC 200s….. and have lost interest in rebuilding anything if it doesn’t need it….