Mikey Posted September 10, 2005 Share Posted September 10, 2005 So my moms car blew out a spark plug. Apparently the dick who owned it first stripped the sparkplug and had it heli coiled. It finally blew out. The garage wants 1800 to replace the head. I can get a head, but it's going to cost a ton of time to do it apparently (3.4 lumina). Brothernlaw is going to attempt an industrial JBweld that they use at his plant for steam fittings. We'll see what happens. If it fails (which I figure it will at some point), can someone suggest another alternative? I can't afford to get it fixed and my mom REALLY can't afford it since I helped pay for the car to begin with. I'm thinking another helicoil one size larger but can this be done with it in the car? Apparently it's hard to get at as it's the rear spark plug of the v6. Quote Link to comment Share on other sites More sharing options...
Furbird Posted September 10, 2005 Share Posted September 10, 2005 The head has to be pulled because the shavings will blow the motor if you don't. And helicoiling a spark plug hole is about stupid to begin with, due to the constant pressure it's under. You're talking about a part that is under direct PSI from the cylinder, and only on one set of threads, unlike head bolts/studs. The head really does need to be replaced, especially since you have to pull it anyway, but the question becomes whether or not you want to go through all that trouble on a car that old. If worse comes to worse, buy a junkyard head or entire motor and take off what you need. BTW, do NOT use JB weld on this. You will never put spark plugs in it again if you do, as the one you put in will be the last one that head ever sees. Until it blows out, probably within the first week, as it is not going to hold that kind of pressure. Not to mention that whole fire thing going on in the motor Quote Link to comment Share on other sites More sharing options...
Ronnie Posted September 10, 2005 Share Posted September 10, 2005 So my moms car blew out a spark plug. Apparently the dick who owned it first stripped the sparkplug and had it heli coiled. It finally blew out. The garage wants 1800 to replace the head. I can get a head, but it's going to cost a ton of time to do it apparently (3.4 lumina). Brothernlaw is going to attempt an industrial JBweld that they use at his plant for steam fittings. We'll see what happens. If it fails (which I figure it will at some point), can someone suggest another alternative? I can't afford to get it fixed and my mom REALLY can't afford it since I helped pay for the car to begin with. I'm thinking another helicoil one size larger but can this be done with it in the car? Apparently it's hard to get at as it's the rear spark plug of the v6. Is it a Ford? Quote Link to comment Share on other sites More sharing options...
XXTi Posted September 11, 2005 Share Posted September 11, 2005 I've used an insert type spark plug repair in the past. You tap the hole with a special tap and screw the insert into the hole. There are four stakes that hold the insert into the head. Very simple. Never had one blow out on me and I certainly never removed a head to install one. Put grease on the tap to catch the shavings. Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted September 11, 2005 Share Posted September 11, 2005 It sucks that it's on the right side (against the firewall) It "can" be done with the head installed with an insert. When you are starting the tapping you grease it, turn one rev. remove and clean off shavings, regrease and proceed. When done to make sure you got all the shavings, duct tape a vinyl hose to your vacuum cleaner hose and run it down the plug hole and vaccum out the cylinder. But it still sucks. Quote Link to comment Share on other sites More sharing options...
Mikey Posted September 11, 2005 Author Share Posted September 11, 2005 So anyone know what this insert is called? Where would I find one? Quote Link to comment Share on other sites More sharing options...
XXTi Posted September 11, 2005 Share Posted September 11, 2005 I'd try your local auto parts stores and explain what you want. I'll bet they can help you. Quote Link to comment Share on other sites More sharing options...
ar50racer Posted September 11, 2005 Share Posted September 11, 2005 Ya, what those guys said, they sell kits specifically for sparkplug thread repair. It will be a pain in the ass, but it sounds like you have more time than money, which is just like me. Quote Link to comment Share on other sites More sharing options...
REXX Posted September 12, 2005 Share Posted September 12, 2005 Get the piston on that cylinder to "top dead center" before tapping. It should be easier to vacuum out the cylinder then, good luck. Quote Link to comment Share on other sites More sharing options...
Mikey Posted September 12, 2005 Author Share Posted September 12, 2005 Yah, I recognize what you mean about TDC. I'll have a peak and see what's up. You guys think I can get this at UAP or something? Quote Link to comment Share on other sites More sharing options...
TechnoGecko Posted September 13, 2005 Share Posted September 13, 2005 I think ya need this... http://www.globalspec.com/FeaturedProducts...m_x_125/23773/0 or http://www.timesert.com/html/sparkplug.html Quote Link to comment Share on other sites More sharing options...
Northman Posted September 13, 2005 Share Posted September 13, 2005 The head has to be pulled because the shavings will blow the motor if you don't. And helicoiling a spark plug hole is about stupid to begin with, due to the constant pressure it's under. You're obviously not talking from experience here :roll: I've Heli-coiled a number of cylinder heads, and it works great if done properly. The Heli-coil insert is stainless steel, giving you a stronger thread than original. If the Heli-coil has blown out, then the threaded insert that Techno provided the link to is the way to go. Mike, it isn't a Z34, is it? If so, then you're going to be pulling the head. There just isn't any way you're going to get down to the bottom of the spark plug tube to cut threads or install the insert. If it's the 3.1-based engine, you should be able to do it with patience & great care to make sure it's tapping straight. Depending on which year the car is, the engine can be tilted forward to allow better access to the rear plugs. I recommend making sure the piston is down when tapping the hole so you don't end up bottoming the tapping tool on the top of the piston which would either fuck up your threads, or damage the piston top. For cleaning, either use the vacuum, blow compressed air into the cylinder, or even fire it up before you install that spark plug. Quote Link to comment Share on other sites More sharing options...
Mikey Posted September 13, 2005 Author Share Posted September 13, 2005 Ok, this is going to work. Thanks. It's the 3.1 engine. I don't know how to tilt the engine, but I'll see what I can do and get that kit. Thanks guys! Quote Link to comment Share on other sites More sharing options...
Northman Posted September 13, 2005 Share Posted September 13, 2005 It's the 3.1 engine. I don't know how to tilt the engine, Just remove the bolts on the front upper "dog bones", which are the mounts that go from the top of the front cylinder head area to the rad support. This will allow the engine to rock back and forth, so you could find a way to hold it in the forward position for more access. Quote Link to comment Share on other sites More sharing options...
Furbird Posted September 13, 2005 Share Posted September 13, 2005 Umm, Northman, I AM talking from experience, as we just had a ASE certified master technician at our shop run into this same problem. Somebody had crossthreaded the hole long ago (not him), helicoiled it, and the helicoil broke and blew the spark plug out of the top of the engine. So, when we sent the head off to have it looked at, they said they couldn't do anything with it and the head would have to be replaced. And please notice that I said helicoiling a head bolt is a completely different animal from helicoiling a spark plug hole. If you helicoil a head bolt, you still have the weight of the head AND all the other head bolts to distribute the load across. A helicoil spark plug hole has the ENTIRE pressure load of the combustion chamber placed solely on that one helicoil, as there are no other threaded items in the combustion chamber. I'm sorry, but I don't think it's going to last very long. Even if I were to consider helicoiling a spark plug hole, which I wouldn't, there is no way I would drill and tap it with the head on the engine as there is no possible way you are going to get all of those metal shavings out of that cylinder. Now granted, on a high mileage and/or old car, it really doesn't matter, but if you're going to do the job, at least do it right and pull the head. But at that point it would be foolish to not replace the head anyway since you have it off. Quote Link to comment Share on other sites More sharing options...
Northman Posted September 13, 2005 Share Posted September 13, 2005 Heli-coils don't break. Somebody fucked up the original install, cross-threaded the plug after it was Heli-coiled, or over-tightened the spark plug. Thanks for your 3rd party experience, and your opinion, but a properly installed Heli-coil is stronger than the original aluminum or cast iron threads. Quote Link to comment Share on other sites More sharing options...
Hobicus Posted September 13, 2005 Share Posted September 13, 2005 So... once you get it fixed, SELL IT!!!!! QUICK!!!!!!! Quote Link to comment Share on other sites More sharing options...
bartonmd Posted September 13, 2005 Share Posted September 13, 2005 Heli-coils don't break. Somebody fucked up the original install, cross-threaded the plug after it was Heli-coiled, or over-tightened the spark plug.Thanks for your 3rd party experience, and your opinion, but a properly installed Heli-coil is stronger than the original aluminum or cast iron threads. I agree Chris... I've seen the heli-coil deal done on 3 different engines and all of them are still together and running strong. Mike Quote Link to comment Share on other sites More sharing options...
Mikey Posted September 13, 2005 Author Share Posted September 13, 2005 Maybe I'll helicoil it then burn it :] Quote Link to comment Share on other sites More sharing options...
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