F'd Up spark plug threads?
 

So i pulled out a leading plug yeasterday (thought the engine was flooded) First time i pulled the plugs on a jspec, plug came out kind of hard, never really loosend up to be turned by hand.

I didnt think much of it, pulled it out, threw in a new one, went in hard which i also thought was strange, i got as far as halfway to putting it in and it bound up, wouldnt go any farther.

Today ibought a thread chaser and could only get it to go half way in

Sound like the symtom's of a previously cross threaded spark plug?

Options? (besides the blatent obvious..)

-Jacob

Well did you stick your finger in it to check for something ? How did the old plug look ? On that thread cleaner use alot of tap fluid run it in and out so it can clean itself don't force it .

the plug likely went in cross threaded and the chaser did the same until it met a chunk of solid aluminum that it couldn't go any farther, remove the chaser and try to start it as straight as possible, once you get it in about 1/4 to 1/2 a thread back it out 1/16 of a turn then go in about 1/4 turn back out 1/16 in 1/4 etc etc etc until it goes in all the way, be sure to crank the engine to blow any debris out of the chamber before putting the new plug in.


edit: do not reuse the plug you installed that cross threaded, at least if you do you need to clean the aluminum off the threads or it will bind up on the way in as well, apply a small amount of anti sieze to the threads and install it.

anti seize
 

As karack stated use antiseize, preferably with copper in it , withstands much higher temps. And for all that are looking at this thread make sure you always use anti-seize on all threads of spark plugs to avoid the galling efffect that willl screw up your threads. rx7doctor

:werd: on antiseize.

Um, stupid question I know... but..

When I installed my spark plugs I turn them in by hand until a certain point where I got a little resistance.

After that I used the ratchet... got a few turns and then got resistance... maybe 5-10ft/lbs worth, I'm not too sure. But it still turns fairly easy with the ratchet...

My question is basically that I know how sensitive those threads are, should I keep using the ratchet until I get a SOLID feeling of it stopping or is where they are tight enough? It seems like I should keep tightening them because I CAN without MUCH resistance... but on the other side, I COULD be cross threading them somehow... although I took them out and put them back in (a few times... thanks to double guessing myself on whether top was trailing or not... shoulda went with my first instinct... corrected myself twice lol) and got the same resistance...

I think it's also possible the threads are dirty, thanks to having not cleaning the holes out all that well after the rebuild... I meant to but I didn't have a spark plug sized tap.

--Gary

Clean it out with a tap. 14mmx1.25 IIRC. They'll thread in with 2 fingers all the way to the stop point if you do this. Use plenty of wd40 for lube while doing it...if you feel a stop, back it out and spray both the hole and tap clean, and repeat. You don't want to go all the way into the chamber, obviously...the T hole stops before the L hole does, but neither one is threaded to the end of the chamber wall. Count and mark the threads that are on a plug, on the tap, so you know how far to go in. Use compressed air or the spray can to remove debris. Very small aluminum shavings getting into the engine internals isn't the best thing in teh world, but it's softer than both the seals and housings so turn the engine a few times with the fuses out then crank her up and it should be fine.

Thank you, i did this method after work today with a brand new tap. It took about 45min however i finnaly got the the L2 plug in as far as L1 and its nice and snug. I blew it out, cleaned the tap and used almost a hole can of 4way spray durnig the hole thing

-Jacob