O.S.! broken spark plug

digger

digger

Active Member
Hey all here's my new predicament. Changing my spark plugs for the first time since I purchased this truck. With 200k miles its hard to believe they are original, but being all Denso plugs and worn looking to boot it makes me wonder. All was going according to plan until my very last one was stuck good. I soaked in PB blaster for the day and then decided to give it a go. Well it broke at the threads. (Pants soiled) fortunately all the porcelain came out with the diode in one piece.
I have now proceeded to try and use a #5 easy out bolt extractor to remove the threads. It is grabbing well but the threads are not budging. I have a mapp torch that I tried to apply heat but due to the depth of the plugs in the 1 gens V6, the torch just goes out if I shove it down the hole. I sprayed more PB blaster and here it sits.
I have read alot of success stories using this method but true to form of how this crap goes for me I have yet to be so lucky. Anyone run into this on their 1st Gen?
 
Update: The threads finally gave way and came out. It also seems much of the thread from the cylinder head came out with it. My next step is looking to re thread this plug hole. Im thinking of going with inserts over Helicoils. any insight?
 
I never had to do this, so I googled it a bit. Helicoil seems to be the preferred method, but I see one big potential hitch with it. You have to break off the little piece of wire in the center of the coil, after it is installed and then be sure NOT TO DROP IT INTO THE CYLINDER. I guess you could possibly fish it out with a magnet if you dropped it, but it is stainless steel and many SS alloys aren't magnetic. This seems like a very Murphy situation, if it can go wrong it will, and at the worst possible time.

The thread inserts don't have you holding on to a slippery piece of wire that is already in the cylinder and probably at the worst possible angle and with zero ability to see what you are doing.

The most useful tip I saw was where a guy started the engine without the new plug in the cylinder, but after the new threads were cut, to blow the chips out of the cylinder. You could see them coming out of the plug hole. Also, grease on the tap, will capture the chips in the flutes of the tap, so grease it up before you cut the threads.
 
WiskyT said:
I never had to do this, so I googled it a bit. Helicoil seems to be the preferred method, but I see one big potential hitch with it. You have to break off the little piece of wire in the center of the coil, after it is installed and then be sure NOT TO DROP IT INTO THE CYLINDER. I guess you could possibly fish it out with a magnet if you dropped it, but it is stainless steel and many SS alloys aren't magnetic. This seems like a very Murphy situation, if it can go wrong it will, and at the worst possible time.

The thread inserts don't have you holding on to a slippery piece of wire that is already in the cylinder and probably at the worst possible angle and with zero ability to see what you are doing.

The most useful tip I saw was where a guy started the engine without the new plug in the cylinder, but after the new threads were cut, to blow the chips out of the cylinder. You could see them coming out of the plug hole. Also, grease on the tap, will capture the chips in the flutes of the tap, so grease it up before you cut the threads.
Click to expand...
Yeah I was thinking the same thing about the helicoils. I have a set of needle nose pliers specifically for reaching down in long narrow places but even they cant get to the bottom of that plug hole. I had never thought of using the cylinder compression to blow debris out. I have a compressor that I can use to blow any big stuff out but I may just try that too as a secondary precaution.
Seems like inserts are going to be the way to go. Headed to the store today I will update later. Thanks!
 
digger said:
Yeah I was thinking the same thing about the helicoils. I have a set of needle nose pliers specifically for reaching down in long narrow places but even they cant get to the bottom of that plug hole. I had never thought of using the cylinder compression to blow debris out. I have a compressor that I can use to blow any big stuff out but I may just try that too as a secondary precaution.
Seems like inserts are going to be the way to go. Headed to the store today I will update later. Thanks!
Click to expand...


I don't know if compressed air will go into the cylinder and blow the chips out as well as a compression stroke.
 
Hey Digger,

How are you? What an ugly dilemma you are in with your Tacoma's spark plug hole. Unfortunately, I don't have any insight to help you which direction to go. How are you going to cement the inserts to the head? I am sure you already know this. The heads on the 5VZ-FE 3.4 are aluminum. I am sure you already know this as well. When you get around to putting your plugs back in, you should brush the threads with anti-corrosive solution to prevent this problem from happening again.

Good Luck,
Paul
 
TacomaLoverExtroa9681 said:
Hey Digger,

How are you? What an ugly dilemma you are in with your Tacoma's spark plug hole. Unfortunately, I don't have any insight to help you which direction to go. How are you going to cement the inserts to the head? I am sure you already know this. The heads on the 5VZ-FE 3.4 are aluminum. I am sure you already know this as well. When you get around to putting your plugs back in, you should brush the threads with anti-corrosive solution to prevent this problem from happening again.

Good Luck,
Paul
Click to expand...
TacomaLoverExtroa9681 said:
Hey Digger,

How are you? What an ugly dilemma you are in with your Tacoma's spark plug hole. Unfortunately, I don't have any insight to help you which direction to go. How are you going to cement the inserts to the head? I am sure you already know this. The heads on the 5VZ-FE 3.4 are aluminum. I am sure you already know this as well. When you get around to putting your plugs back in, you should brush the threads with anti-corrosive solution to prevent this problem from happening again.

Good Luck,
Paul
Click to expand...
The thread insert called for an RTV high temp silicone for adhesive and the insert also use serated threads at the top portion of the insert that are expanded into the block to lock it in place. And yes I also brushed a high temp antisieze on the new plug
 
On a side note. I drive this truck like an old man however you wouldn't know it at first but the supercharger really moves this thing when you need it too!
 
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