Spark plug thread is no good

Hi all,

I just recently bought my 96 Tacoma V6 4x4 with 210,000 on it. I still need to smog it so I did some quick tune up, ie, oil change, air filter and spark plug replacement. What I noticed was for cylinder #3, the spark plug threads have been redrilled/retapped for a "spark plug insert". I've bought all replacement parts, including the insert, and had gone to install it by following the manufacturer, of the insert, instructions. Upon installing, it felt like I had bottomed out, but it just kept turning. After the second revolution, I know the threads are no good so I stopped and re-assembled everything together.

I started the truck up, it idled smooth and sounded great, but when I rev'd it, cylinder #3 started popping. I knew then that the spark plug wanted to jump out.

My question now is, are there any possible fix to this spark plug thread even though it's been fixed once? What recommendations do you guys have?

I was thinking about replacing just the passenger side cylinder head, but with un-matching head I am uncomfortable with that.

Let me know what you guys think.

Thanks in advance.

 

Replace the head at this point. If you have the money I would pull the other head while you are there and have a machine shop rebuild it also due to the miles on your truck. I wouldn't worry about them being "non-matching" as long as you get the right head for your year truck.

 

What he said ^^^^

At this point with the threads already having been repaired once, you risk trying to do it a second time. I never was a fan of spark plug rethread inserts anyway, since I have seen them come loose when threading in a new plug, and fall into the cylinder. Replace the bad head and have the other head inspected and rebuilt. you should be fine after that.

 

if you have already done a time-sert (not helicoil) then that head is finished

if you have not done a time-sert yet, go for it. that is the last sound option

Or disconnect injector and run as a 5-cyl

 

Thanks for the response.

It really is a bummer to have to do this because I bought the truck for a good amount and now no more money to do anything.

Anyways, thanks for the advice.

 

I don't have any history of the car at all except that I am the 3rd owner. I'm not even sure if the threads will be good enough to hold the time-sert.