I was helping my buddy change his spark plugs and we found out one of the holes is stripped out and the plug wont even screw in. It just slides in and out. Is there any way to fix this without some serious machine work being done? Thanks.
check out www.lock-n-stitch.com they have a spark plug reapir you can do by drilling out the original hole tapping and putting in a full thread insert, It's not a heli-coil. Best repair pout there. Shawn
What kind of motor? Any decent automotive machine shop can put a Heli-coil in it for you. But that means pulling the head.
OK, Dont laugh, The head is a Dodge Neon 2.0. The car is only 3 years old and he doesnt know how it happened. Thanks for all the input!
Re-thread without removing the head. Check out this product. I haven't used it, but it seems cool: BackTap
Spark plug repair with the heads on: make sure piston is at BDC, heat up area around spark plug hole with a torch until dull red. take your mig and weld up some bead in the hole, starting as low as you can get in the hole.let the head cool then drill and tap tne new hole. rotate engine so that one of the valves in that cylinder is open. then put a shop vac over the hole to vacum out any chips of metal. then crank the engine with out the spark plug in a few times. If there is any material left it will burn up with the motor running.
Fastsporty, your idea won't work, as I am pretty sure the head is aluminum. Josh, you need a threaded insert, such as a heli-coil or others as suggested. You should be able to do it without pulling the head. Threaded inserts are very common to use in aerospace, in fact they are stronger threads when installed than the original metal threads would have been. There is nothing wrong with using a threaded insert.
A similar thing happened to a guy on another forum I read. Except it was a Saturn, and the spark plug blew out of its hole while the car was running. Helicoil is definitely the right thing to use.
Heli-Coil...fast,cheap, easy and will last as long as the engine....welding dumb idea and won't work on any engine ..unless done by a qualified machine shop...very common problem on the aluminun sewing machine engines in those e-cono boxes..fatchuk
[ QUOTE ] How hard is it to put in a Helicoil? I have never done it. [/ QUOTE ] Drill hole - straight as you can, easily done as the drill is fairly self-guiding due to the original hole. Tap. Screw in Heli-Coil. Break off tang. Done. The Heli-Coils are a wound wire coil with the wire having a diamond shape that matches the angle of a threaded hole. We've found Heli-Coils at Kragens among others - NAPA for sure - and the 3/8-16 size is under $20. You will need the proper size drill for the job so keep that in mind. I believe some Heli-Coil kits come with the required drill, but the larger ones don't Pulling the head or using a shop vacuum while drilling is up to you, but a lot of shops do them with the head on. Fwiw - in the good old daze and probably still today, most tuners at Ascot - SoCal flat track for bikes - drilled out perfectly good spark plug holes in the bike heads and installed Heli-Coils. The Heli-Coils are way stronger than the original aluminum threads and just as strong as the cast iron threads. There's a whole lot of plug changing with flat track bikes. As a normal part of tuning and they have "start-up" plugs as well.
Uh, My reply was a joke, Hence the at the end. You should ALWAYS pull the heads to do any machine work on a head, And even if you were going to get rid of your car in a few thousand miles, why screw over the next guy, or mechanic? Get off the H.A.M.B. go out int the garage, pull the frickin head and put a helicoil in it, it could of been done by now. I guess so could my girlfriends brakes
Pull the head off if you can. I've had bad luck dipping the helicoil drill/tap/tool in grease. You could always disconnect the injector and make yourself a three cylinder
I bet he did it pulling the plug out. Was the motor warm? Never pull the plugs on a warm engine that has aluminum heads because you will risk stripping them out. And Always use some kind of antiseize on the threads of the new plugs so it doesn't sieze in the heads. Most people don't put antisieze on when they are changing they're plugs them self so when the next time they go to change them they won't come out with out tearing stuff up. I used to hate changing plugs on motors like that when some one did it before me and didn't use any antiseize its a bitch getting the plugs out. Use the heli coils or the inserts thats the best things for it. Good luck.
Done it plenty of times over here on the with all the cheap-ass European alloy heads, can't remember who sells them but you can get an insert that is not the wire coil type. The ones i've used are a solid insert & come in different lengths, a little tip once you have tapped the new oversize thread....fit a greased spark plug into the insert & then apply some threadlock to the outer thread on the insert, screw the insert & plug in firmly until it seats, give it a short while for the threadlock to cure & unscrew the plug which should come out easy with its greased threads.
i like the threaded inserts better than heli-coils for spark plug holes myself,but i also won't do one with the head on so i can grind down any sharp edge that might be left in the combustion chamber.i also like to do all of them so there's no chance of having it affect the heat range of one plug from the others.
As Yorgatron said but if you don't pull the head you can use one of the old plugs as a guide to give you close to right length for the insert.
You can do in on the car. there is a thread kit called a "Big Sert kit" it's pricey, but...it works like a champ! you can't use a regular heli coil. it has to be a Time sert. Otherwise it won't hold properly. they are about $400.00. they are for the ford V-10's but work for many cars... Good luck!
As someone who once stripped out an oil-pan plug hole, I don't want to insult anyone. But I would say, remember NOT to wrench hard on anything that just needs to be "snugged," not torqued by Armstrong power. (Aluminum is great, but it's not titanium.)
I BEG to disagree here. I have Heli coiled heads on and off the motor for close on 40 years and done corectly they work just fine.
Sav-a-thread kit (by HeliCoil) sold at NAPA. This is a solid threaded insert, not a typical coil insert like HeliCoil usually sells. It comes with a one-piece tap/reamer/tap that screws into the old threads, reams the hole larger, and cuts new threads for the insert. On aluminum heads, you can easily screw this thing through with a 3/8 drive ratchet. Lube it well and turn it slowly, with plenty of back-turns to release the shavings. The insert screws into the new hole and the kit supplies a special punch to lock it in place. I'd also use a heat proof sealant on the outside of the insert. If the car's not too special and since it has an aluminum head, I'd do the job with the head on but try to get most of the shavings out.
I did a double take when I saw C 9 's reply & then saw how old this thread was. I've been servicing aluminum head imports for 40 + years, lots of VWs. IMHO Heli-coils are the best repair. The various threaded inserts will usually come back out the next time you change the plugs, the exception being the Time serts that have the lugs that you drive in to stake the insert in place after installing it. Anti seize is your friend , I always use it on plug threads.
I've used helicoils on everything from lawn mower engines to tractors and combines, never had one fail yet. Never took a head off to do 'em, either. use a small hose and lots of air pressure to blow everything out when you're done. I have used the inserts, too, Wisconsin sold them for years. I think the later V4's came with them from the factory.
This seems to be an issue with some of the 4.6 and 5.4 Ford motors out there as I have seen numerous posts on them blowing the spark plug out of the head. I think there is a Ford Bulletin on it as well . I know several guys that have fixed theirs without pulling th ehead and they seem to be working fine.
4.6 and 5.4's have a couple nice plug problems.... We've had lots of 2 valve modular motors with blown out plugs, and the 3 valves have problems with the plugs breaking off... But there's special tools to fix 'em!!
I put helicoils in the heads on my off topic aluminum head, pulled the head,took it to work to do the drilling on the bridgeport, and put in spark plug coils, way stronger then the original aluminum threads. also if you pull those plugs,get a spark plug chaser tap, grease it up, and chase all the good threads, you will be amazed how much carbon and junk comes out. the chaser doesn't cut threads,it cleans out the threads, when you thread in the plugs, use your fingers not a wrench ,make sure they are turning in correctly, if you use a wrench to install plugs in aluminum, you can cross thread without feeling it,
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