Stripped spark plug thread

smeta · #1 (**permalink**) 04-19-2006, 11:39 PM

Ok, I don't know much about cars, but here is my situation...

I have a 90 Corolla Wagon w/ 253,000 miles. I blew a spark plug today and the mechanic said the threads are stripped. He tells me that if he puts an insert in to anchor the spark plug, metal shards will be stuck inside the engine and really mess up the car. Is this BS or not? To replace the cyclinder he tells me it will be $1500 (the car is only worth $1400).

TIA!

RitcheyRch · #2 (**permalink**) 04-20-2006, 07:48 AM

They have kits to put a heli-coil in there. Some of the major auto parts stores carry these.

If you dont feel comfortable doing this find a good reputable shop to do the work. When they drill out the cylinder head they will coat the special drill bit and tap with grease to collect the metal pieces.

smeta · #3 (**permalink**) 04-20-2006, 10:40 AM

My husband can do the work, he just hasn't had a chance to look at it yet because I am out-of-town.

Any special instructions for him?

RitcheyRch · #4 (**permalink**) 04-20-2006, 01:37 PM

No real special instructions. If he has installed heli-coils before than he will not have any problems doing this.

QUOTE=smeta]My husband can do the work, he just hasn't had a chance to look at it yet because I am out-of-town.

Any special instructions for him?[/QUOTE]

cupidstoy · #5 (**permalink**) 04-21-2006, 11:09 AM

safest way is to remove the head and drill it out. it's more work but not more work then rebuilding the engine if a little piece of metal gets into the cylinder and starts grooving out the wall so it burns oil or worse, causes a hot spot and the piston or rod shatters and goes through the block.

another consideration is why did you "blow" a spark plug in the first place and why did it strip the threads? if the plug was loose, the threads could have "burnt" but the car would have been running pretty badly up till that point. if the mechanic overtightened the plugs last time they were out, that could have stripped the threads and caused the loose plug and then the repairs should be on that person. i realize that may be your husband

or may be hard to proove.

anyway, just noting that something else is going on here and the root cause should be found and fixed if the car is worth keeping at this point.

good luck!

mustang67408 · #6 (**permalink**) 04-21-2006, 01:53 PM

Quote:

Originally Posted by RitcheyRch

They have kits to put a heli-coil in there. Some of the major auto parts stores carry these.

If you dont feel comfortable doing this find a good reputable shop to do the work. When they drill out the cylinder head they will coat the special drill bit and tap with grease to collect the metal pieces.

Great advise, and even if a piece of metal shaving gets into the cylinder they usually just blow out the exhaust.
The grease on the tap usually collects most of the shavings.

qfjsy · #7 (**permalink**) 08-15-2009, 07:44 AM

if the plug was loose, the threads could have "burnt" but the car would have been running pretty badly up till that point. if the mechanic overtightened the plugs last time they were out, that could have stripped the threads and caused the loose plug and then the repairs should be on that person thread insert helicoil