Stripped sparkplug "Help" 3.4l

Hes just playing the "better safe than sorry" card. Nothing wrong with that. plus he's an ASE smog tech. He works on vehicles daily. And me, im a machinist apprentice 2 days a week helping to rebuild engines while an ASE parts specislist supplying and disgnosing car parts with mechanics the other 3 days. his suggestions, though douchy, aren't bad at all.

Honestly ive never heard of shavings from something like this ever affecting the cylinders or their walls. This includes the myriads of ford 5.4 engines with the shitty spark plug design, that i used to see having issues weekly, which should have been a recall, or better yet, a lawsuit.

The blow out method is actually a valid way of doing things. Cylinder walls are so tight ( around .001"-.005" of play MAYBE) that there would be nearly no way for the fallen shavings to have any affect. Only if, maybe, the cylinder walls were already damaged from some other issue, would the shavings have an affect. But this should vener happen with proper maintenance.

Honestly, if the blow out method doesn't completely work, the remaining pieces will just get blown out of the exhaust. Worst case scenario is the valves pinch a shrivel of metal and become very slightly opened. Not likely.....

I personally just dont want the OP to use that welded tool that allows a greater chance of error by expecting it to go in straight when it's slightly over cutting the new threads. The tool was designed to be used slightly loosely, allowing it to guide itself in. He's removing that feature and can potentially damage the new threads this way.

 

Here is a cheap alternative I have used in the past with excellent results . Car engines , boat motors , etc . Anything that uses a spark plug .
Get yourself a cheap vaccuum blow gun with a plastic flexible tube .
I have used this countless times as a quick fix for removing metal from a very small space and it works very well Just dont stand in the way

 

Completed and doing Great.

 

great!

 

This type of repair has been performed on aluminum cylinder heads for ages and is the accepted repair industry wide. Pulling the cylinder head is completely unneeded due to the type/size of shavings left in the combustion chamber. I have performed so many cylinder head repairs it is not even funny. Most of my repairs center around the 3.0l because of cross-threading, the 2uz and 5vz are a close second
due to blow outs. I have never had to pull a cylinder head/rebuild a short block due to shaving damage. I bore scope before starting to check for large collections of shavings. I have bore scoped after for damage expecting to find something, have yet to see anything yet. It saddens me that a tech is recommending to pull a head when that is not the industry norm.

I have been an ASE MDT for 18 years now, Toyota MDT certs also. I have not taken any of the new Hybrid ASE tests yet because they were not out at my last round of testing but I'm Toyota Hybrid certified.

That tool did look sketchy, but as a technician I've had to build plenty of tools to get the job done, some work, some don't. I don't like the heli-coil insert for other reasons, mainly the way their insert locks into place doesn't seem to work in the long run, they like to come out with the spark plugs. The Time-Sert has a better way of locking to the cylinder head due to an interference fit designed in.

 

I understand the concern with the welded bolt to the tap. We took Great time and care into ensuring the Trueness of the pieces when welding them togather. And when tapping the head out it all seemed to line up just fine and followed itself in. It took about 5 attempts due to me removing it completly cleaning the shavings off of the tap and applying fresh grease.

 

that was the right way to do it.

the straightness of the tap extention is not that crucial as it in this case pretty much has to go straight because of it following the old plug hole... in order to get it to skew you would really have to go nuts with the side forces or be an absolute idiot and use a pneumatic wrench.

you seem too have used more mecanical common sense and forethought than most so good job op.

 

I appreciate it. Yes this was my first time doing this, yet it seemed to have went fine. I do all of my own work so yes I thought it all through beforehand. Same principal as "Measure twice cut once".

 

My own Tacoma is the only Toyota i work on regularly aside from doing emissions related repairs and basic maintenance on. All my 11 or so years of experience revolves around BMWs and Mercedes that are values from 30k to 100k. First off, i dont need to deal with striped bolts on heads unless the car is brought in from a DIYer or Pepboys mechanic that fucked it up as we see described in this post. I recall only once with this on a spark plug threading, its been more commonly an item to repair with timing case and valve covers, once with a head bolt, though its was one of the early aluminum blocks in a Merc E300 or 320.

I always prefer timeserts as the design better locks into the surrounding material and can withstand higher torquing. The downside is that you will get a good amount of metal bits from the drilling process.

Would it probably be fine using the air vac that the guy above posted above, yea probably. If i wanted to work that way i would go work at Firestone where i only get paid by the clock, not the job. If a customer is willing to pay for the $2000 in labor for a $300 rebuild kit, $200 for head testing, and a $20 insert, throw in some fresh fluids and belts in there. As well i have the luxury of having only car to work on for a day or two. Then guess what, im pulling the freaking head.

 

Thats good, Ill give you a A for ingenuity, still would try to find a tap handle with a extended flute specifically for the reasons mentioned above. But seeing its a Toyota engine, its hard to break it. One thing that could be done, get the highest viscosity oil you can find, like some 190w gear oil. Put that in the cylinder before you begin the process. Any metallic bits should be suspended in the oil and allow you something to vacuum out at the end.

 

With an aluminum head you have to use a Permatex or Loctite activator for anaerobics. On any non active metal such as aluminum this will prep the metal and increase the bond and cuts the Cure time in half. It's important if you want that fix to last.