Spark plug thread stripped

[fishtank Junior Member Find all posts View Profile Close fishtank]

Does anyone know if it's possible to rethread the head where the spark plug goes on a 98 Prado? A mechanic I took it to said he can't do it as his tool isn't long enough. Surely there is an extension piece that could be used. He wants to pull the head off and do it from underneath but that will cost thousands. I see his point but googling it shows many other people rethreading other cars quite easily. Is the Prado head much more difficult for some reason or should I try another mechanic ?

[Toopy Member Find all posts View Profile Close Toopy]

I'd be worried about the swarf (metal shavings) dropping down into the cylinder and scoring the walls once the engine is started if doing it from above. Even if you used heaps of grease to try to catch it.
Find a friend, buy some tools, offer a carton or 2, cash job etc... pull the head and do it properly or it would probably cost you more in the long run.
It's not really a hard job, just will take some time. If you follow the factory manual and can put a meccano set together you can do it yourself. really the only thing is to make sure the head bolts are torqued in the correct sequence to the correct tension.

[Walky88 Member Find all posts View Profile Close Walky88]

Yes you can fishtank.

I have done a couple of prados at work now and was a pain in the ass but doable.

There are a couple of mobile guys that will come to the car and do it for you.

Try Prothreads or Threadtech.

Have used prothreads recently and he was good and charged fairly!.

I see you in Banyo, is that banyo brisbane?

[AussieAndy Find all posts View Profile Close AussieAndy]

A big +1 for Threadtech, if we ever have issues at work they usually come to the rescue. I wouldn't attempt to re thread that myself, best to pass the tricky ones off to the guys that do it all day everyday.

[fishtank Junior Member Find all posts View Profile Close fishtank]

Awesome thanks guys I'll give them a go. Yes banyo brisbane

[fishtank Junior Member Find all posts View Profile Close fishtank]

So just a few questions for Prothread. Is there a certain depth they need to tap down into or will the spark plug only screw in to a certain depth. Or does it not really matter? Will there be issues further down the track if any shavings fall down into the cylinder? Or do they have all of that covered?

Hopefully have them come over by the end of the week. Prefer to get the Prado up and running over scrapping and having to buy a whole new car!!!

[fishtank Junior Member Find all posts View Profile Close fishtank]

So Prothread came and rethreaded the spark plug hole for me and my new coils arrived. Fired it up and its making a different but more serious sounding ticking noise again!!!

I am wondering if it might be the spark plug I was only able to source a cheap champion spark plug and not the NGK one as my local parts store didn't have them in stock. I compared the two and they are different lengths. Would this make a difference?

Is it possible that Prothread tapped down too far? Could the spark plug be hitting/tapping the piston if it was screwed down too far?

I tried moving the. Champion plug to another cylinder. Still ticked. I removed it completely and ran the engine with 1 cylinder short but it coughed and spluttered and it was too hard to tell if the ticking was gone.

I guess I'll have to go get another NGK plug tomorrow to see if my theory works.

[Walky88 Member Find all posts View Profile Close Walky88]

Can't go too far as the spark plug it self bottoms out.