Mitch92

One of my spark plugs is leaking on my 92 what is the best way to repair it

rickneworleansla

Does it just need to be tightened or is there something else wrong?

Mitch92

they guy that changed them pulled the treads I think and now it leaks and sounds like an exhaust leak but it is the #7 plug leaking

rickneworleansla

I've never had to rethread the holes before, maybe someone else can take this one. Make sure they always use anit-sieze on the threads of the plugs.

Good Luck.

Demonic85

Are the threads in good shape? Torqued to 20 ft lbs or whatever yours call for? I see no reason for it be leaking otherwise unless the head itself is damaged.

Mitch92

The threads are messed up

Demonic85

Get a tap from a hardware store and fix those threads. Sorry I have no idea what size they are though, i'd take a spark plug along though.

redrose

best fix is to weld the hole up, drill and tap new threads....will req removing the head from the engine...might get lucky with thread repair tool (tap) available at any auto parts store and not need the ''big fix'' but say a bunch of thanks prayers if that works.

most common repair is ''heli-coil'' insert...requires drilling oversized hole and tapping that to accept a ''coiled wire'' insert...can be done on the car but not recommended...check with any auto machine shop that does cyl head work or a ''friendly'' motorcycle shop (they heli-coil everything)

never change plugs when the is engine ''hot'', to avoid this problem...if a ''cold'' engine plug resists removal, heat the body of the plug with a torch and allow several hours to cool before retry -- some take several heatings to loosen (happens mostly to cars that have been years between plug changes)

rick lambert

Most auto parts stores carry a spark plug thread chaser, get one and make sure the area is clean, then chase the thread slowly. If you're lucky it will work...if not the guy owes you a repair. I'd suggest a heli coil, but others may suggest as above.

For the future, when you change the plugs always either use a short piece of fuel line or an old spark plug boot and wire to thread the plugs as far in as possible before using a wrench.....prevents cross threading.

Blownfuel1

They make a tool just for tapping (Well, chasing actually) see here: http://www.partsamerica.com/productd...egoryCode=3482

I never used this one, but the idea sounds good (tapping from inside the cylinder to keep the shavings outside the cylinder): http://www.partsamerica.com/productd...egoryCode=3482

14mm Back-Tap Spark Plug Thread Repair Tool

The Back-Tap 's patented collapsible design allows it to be placed through the spark plug hole and into the chamber.
A mandrel is then drawn back, expanding the tool 's threaded area and threading into the clean threads at the bottom of the spark plug hole.
The Back-tap repairs the damaged threads as it is drawn up through the spark plug hole, bringing debris and metal filings with it
640811H

NO Need to pull cylinder head!
NO Metal fillings in engine!
NO Coil insert needed!


and if that doesn't fix it, repair the threads with a Heli-coil insert:

http://www.partsamerica.com/productd...egoryCode=3482

If you go this route, you'll need to be very careful to minimize the amount of shavings you get into the cylinder while tapping the hole for the insert. I would put that cylinder at Top Dead Center, and pack the taps threads with grease to capture the shavings in the slots of the tap, and clean & regrease the tap several times during the taping process. If you have access to an air compressor, I would get one of those long thin blow guns that you can insert into the spark plug hole to blow any loose chips out of the cylinder.

Blownfuel1

Also, get a can of Anti-seize while your at the auto parts store, and put it on the plugs when you reinstall them. I recommend the bigger one http://www.partsamerica.com/productd...egoryCode=3287, cause once you get used to using it, you'll find you use it a lot. I always put it on lug nuts to prevent galling, anywhere dis-similar metals come in contact with each other and no other sealer is required!

rick lambert

I wouldn't use grease on the tap...traps the shavings alright, but can also cause problems. And their aluminum heads,doubt you'll get enough into the cylinder to cause any problems. BTW, I had to chase one of mine, and it worked out fine.That was 4-5 years ago. Just take it slow.

Mitch92

thanks for everyones help I will get on this eve and get this fixed

Blownfuel1

I see your point, Rick. It would suck to get a shaving caught in the threads your cutting and mess them up too. That's why I suggested cleaning and regreasing the tap often (I was thinking like every turn and a half to two turns in, prerhaps I should have been clearer) . Chasing the threads can probably be done dry with no problems, but if he has to cut new threads for a Heli-coil, and doesn't use grease, then some kind of cutting lubricant should be used (cutting fluid or real light oil (like 10 weight), to prevent the tap from chattering (or maybe I'm just being to ****, I've been accused of it before!)

redrose

there are some cutting ''oils'' made especially for alum that work better, but plain ole' stinky WD-40 is pretty good, lots better than oil or kero, imho.

if the threads are just ''buggerd up'' by cross-threading, ''chasing'' the threads often restores serviceability albeit with some loss of strength and extreme care should be used in future plug changes...if the threads have been actually ''pulled'' the plug hole is oversized and there is nothing left to ''chase'', heli-coil or welding is reqd.

JAKE

I recently chased the threads on #8 and used a thread chaser I bought at Advance Auto Parts.

I put heavy grease on the chaser's threads, started the chaser and made one half turn, then removed the chaser and cleaned the threads on the chaser. I re-applied the grease did the same thing again; one half turn, remove, etc. I ended up doing it that way, maybe five or six times. I worked very slowly.

Surprisingly little metal was removed in the process; the chaser straightened the threads in the head as opposed to cutting them.

Worked slick as goose-grease.

Jake

rick lambert

Jake, but that was really unecessary, see, the grease can infact trap shavings and gaul the threads, not saying you got lucky, but did accomplish it by only going a half turn. A light cutting oil can be used, but I've generally found it unecessary on aluminum with very few threads..such as spark plug holes. And it doesn't surprise me you got very few shavings...when chasing threads, that's why I said I wouldn't worry about the amount of shavings entering the cylinder, what little there is will probably escape through the exhaust valve. It would take one heckava large piece to cause any problems.

redrose

[QUOTE=rick lambert;1562191858 wouldn't worry about the amount of shavings entering the cylinder, what little there is will probably escape through the exhaust valve. It would take one heckava large piece to cause any problems.[/QUOTE]

carbon flakes from the piston tops/ cylinder head routinely ''depart'', on rare occasion get trapped in piston/ cyl block crevice or between valve/seat, are much harder than aluminium...have seen heads ''port-matched'' with only a shop rag stuffed down inside the head, shop vac post-op cleanup was ???, teardown after race several hours later showed no evidence....was ''up close and too personal'' with explosion (burning) of alum flakes from saw-cutting, would suspect the same will happen at first start-up of engine.