Some questions that arose while I tried to change the spark plugs on 2004 LS430 (135K mi, don't believe they've ever been changed)

1 There was a small tear on this sleeve that grew progressively larger as I finagled out the ignition coil. Is there an OEM part # for this? The service manual does not mention one. Is the car safe to operate like this?
2. Given their age, my spark plugs are super tight...I'm afraid of stripping the threads or worse breaking the spark plug itself. Is spraying WD-40 down there safe or is there a better way to loosen them? I have tried wiggling back and forth.

 

1. I wouldn't worry about the torn sleeve, you might call a dealer and see if they are sold separately.
2. I would not use any lubricant, as it might not do any good and worse could cause the wrench to slip and break something. Others may have different opinions. Have a professional take it out.

Once you loosen the plug, if it gets disconnected from the socket insert a magnet to retrieve the plug. I have a slender telescoping magnet with a round head the size of a dime and it is a very handy tool for job such as this..

 

Thanks! Everyone said they are super easy (and it does seem so if your plugs cooperate), so I want to give it another shot before heading to a shop. Just got a longer 1/2in ratchet and will go at it again tomorrow!

 

You really shouldn't need to force it, there is a very real chance you have a cross-threaded plug from a former servicing event

 

I wouldn't know if it was cross-threaded or not unless I counted the turns and tried to get a new one back in right?

AFAIK, every single service for the car has been done at the dealer and shows up on the Lexus Drivers site. So while unlikely, there is a definite possibility they took it elsewhere and it wasn't recorded on Carfax either.

 

The plug shouldn't have nearly the amount of resistance you are describing unless you have a cross thread issue, or the plug galvanically corroded into the head, or god forbid you have aluminum to steel galling.

The former and the latter are fatal to the head

 

Be very careful using 1/2" drive tools under the hood. It might be ok for a spark plug if you know what you're doing but if not you could easily damage something.
Take it to a professional.

 

The sleeve isn't available at the dealer Toyota/Lexus doesn't sell it seperately, it's ok for the sleeve to be missing or torn it won't affect anything other than appearance.

On a side note ya'll are crazy around here if I didn't know any better I'd expect ya'll to tell him to take his car to the dealer to get the tire pressure checked too. I know luxury car owners don't typically work on their cars but some of ya'll are on another level.

 

When you have been changing plugs for as long as I have (40 years) you get a sense of what is 'normal" for torque required to remove them, and it is not a lot like Striker says. If I was in OP's situation and "normal" was not working, I would definitely leave it alone and take it to a professional as you face a major disaster if you break the plug trying to remove it or something else bad happens. For example, you may get it out but not be able to get a new one back in due to damage to the threads.

In my early days of wrenching when I did not know what I was doing and had nobody giving me advice or forums to turn to, I made a lot of bad mistakes, which will go unreported on this forum. LOL I still make a few from time to time, but less now...

 

Totally understand that 13 ft*lbs is not a lot, but the ignition coil bolts are at 5.5 ft*lbs and they definitely took more than that to remove - it looks like they haven't been touched since 2004! This seems to be a very common problem with long-life iridium or platinum plugs. Isn't it expected that these would require more than the average amount of force to remove at 135k versus conventional plugs that come out at <60k?

Anyway, I don't want to be foolhardy and cheap out on a $350 repair (that's what the local specialist quoted) and potentially turn it into a much more expensive one. But am I basically paying for the expertise of the someone who knows the feel of spark plugs?

Between the issues Striker mentions how will a professional handle them? This is what I've concluded from my research - note I don't intend to do any of these myself...

1. Cross thread issue - they simply overcome the resistance with more pressure, see if it is in fact cross threaded, and then potentially re-thread using a tool?
2. Galvanic corrosion - lubricate w PB blaster/WD-40 then retry
3. Aluminum to steel galling - ??

Are 1 & 3 actually fatal? It seems like cross threading is pretty common. Do I have to remachine the head at 135K for these plugs or leave them in until they eventually misfire? Is the professional just going to tell me the same thing?

 

Well to put it simply if they are the ones that mess it up they owe you a head. The TQ spec is kinda useless to be honest unless you have a 100% new head and plug with zero debris effecting the reading. There is a very good reason the packaging on replacement plugs tell you to only go 3/4 a turn past snug and why I always recommend to use anti-seize and go by feel but that method requires the person doing the tightening to know exactly what the threads should feel like and where the yield point is.

Its much more risky on alum heads vs iron for both removal and install since anything going wrong in both directions can ruin the threads and if the head doesn't have much area around the original threads it may be impossible to insert a helicoil if the threads are damaged to the point of being unrepairable.

If you take it somewhere and simply say "I want plugs changed" it should become their problem, I have done plugs on hundreds of cars and some of them literally came in with extreme misfires and failures to start since they went 200K+ miles on OE plugs. Even in cars like that or that received a lot of abuse the plugs don't fight like you are describing unless something was physically wrong with the threads. The worst ones are the old taper style plugs (no crush gasket, just a machined taper to seal) on 60/70s cars that are OE and almost rusted solid to the heads, even those don't require a 1/2 inch drive to get moving again.

 

Striker speaks the truth, One other thing for OP to consider, when I did my plugs at 120K ~ in my '05 a year ago, the factory plugs virtually looked like new and all came out without difficulty. Since your plugs are only at 135K miles, they are probably good for now at least.

 

Thanks for all the information; I'll watch the pros do it and will hopefully change my own at 250K. Will settle with just doing brakes and fluids for now

That seems to be pretty common occurrence, so I'm not too worried about changing them immediately. Might do them early next year along with the motor mounts.

 

Agree. Also based on OP's posted text, I assume that they might not have a lot of diy automotive experience. As others have posted changing plugs should be a straightforward job on the LS in terms of effort. Having to force anything in plug change is a possible sign that OP is doing something incorrectly, or that something else mechanical is going on where an experience pro could diagnose and avoid a potentially serious mistake (breaking a plug off, damaging the head, etc.).