[ether_joe]

Okay. So I had a problem this afternoon which may have grown into a bigger one.



#1. I'm driving along the highway at about 80 in 6th, when I start getting a loud puttering from the engine. I pull over and see that my #4 cylinder sparkplug wire has come out and is just sitting on the top of the engine. At the end of the wire, lo and behold, is the sparkplug itself.



#2. I notice that the hook tip of the sparkplug has broken off.



#3. I call a Porsche mechanic friend and discuss. I then replace the sparkplug with the handy sparkplug tool from the Porsche toolkit.



#4. I tighten the sparkplug down with what I think is enough torque, but not too much or so I think



#5. I start the car back up, and drive to the nearest Kragen on 3 cylinders, and buy another sparkplug. I go to my friend's and we take out the old plug and start putting the new one in.



#6. Here's where the story goes bad. We take a torque wrench and begin torquing to spec. The sparkplug starts to screw down, meets resistance. . . and then the resistance eases and the sparkplug starts turning again.



And that's where we stand right now. I can't tighten down the sparkplug. So. . . goddammit. . . have I stripped my sparkplug thread? Did I tighten down too hard at step #4? Could the original problem which caused the sparkplug to pop out, damaged the threads in the process?



I changed my sparkplugs last spring.



Potential solutions. We did some digging around on Rennlist. . . seems like a heliocore solution wouldn't be advisable for a high-compression situation like a sparkplug. We are considering the possibility of bringing the head to a machine shop and having them re-thread the hole. Or, another potential solution, we could drill new threads and use a bigger sparkplug?



Anyhow there you have it. suggestions and feedback are appreciated.





thanks

Sean

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[Renalicious]

Doh, that sucks. I can't say I've ever heard of a spark plug socket becoming stripped, despite hearing stories of spark plugs being screwed in so tight to almost break tools. Maybe it was loose and all the movement caused the socket to get worn out?

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[flash]

before losing hope, i'd run a tap back down there and see if it's just a buggered thread that is causing the problem - sometimes you can clean that one up and the rest are enough to hold torque

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[gryphon]

I'm not sure I would compound the problems by using a tap without first removing the head. You don't want any metal fragments inside the engine which could possily damage the rings and/or cylinder walls.



Tom

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[ether_joe]

yeah, these thoughts have crossed our minds. The engine is turned off until we get a shopvac with a small hose in there to sweep up the bits of metal. We were thinking about a tap too. Arash didn't have the right size tap so that's on the list as well. I'll keep you posted.

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[josephsc]

Yeek! That's one of those nightmare situations I hope to never encounter. I hope it's less serious than it seems.... <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />

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[flash]

no need to vacuum - you could roll the engine around until those intake valves are rocking open just a bit - then pressurize the chamber through the intake - any flakes will blow out the hole



running the well lubed tap down one thread at a time, removing it, cleaning it, and re-oiling it each thread, will minimize the chance of anything getting in there

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[ether_joe]

all right. . . thanks for the advice. we'll see how it goes tomorrow.



I'm heartened by what I'm finding on the time-sert.com website. . . they have kits for this situation specifically for sparkplugs which makes me feel a bit better.



I'm goin to bed. . . hopefully dream happy dreams. . . <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />

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[rustech]

One of the old tricks when working with metal shavings over an exposed combustion chamber is to coat a small rag with vasoline and stick it down below the threads, then when done bring it back up with the metal shavings stuck to it. Good luck with the operation.

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[oppositelock]

If you use a regular tap, put grease in the channels to trap the metal bits. Also there is a special spark plug hole tapper that collapes, put in the hole, then twist? to put back to full size then unscrew out of the hole. Search internet to find tool, but you'll have to wait till it is shipped to you. I can not remember the name of it. Timesert is better than heli coil and will make a nice repair. Mitch

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[FRporscheman]

OK so a vaseline-soaked rag, a greasy spark-plug tap, a thread insert, and that's it? Almost sounds easy...

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[ether_joe]

headed down to a recommended mechanic right now to see what they have to say. His opinion was that, although he has time-sert, that heliocore was more appropriate for aluminum.



Anyhow we'll see what he says.

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[ether_joe]

good news! barring complications, I am in for just $200 for a heliocoil insert.



Get this - interesting detail - the mechanic said he doesn't use time-sert for Porsche aluminum heads for the following reason. Timesert is made of heavier steel, and inside an aluminum head, it changes the thermal dynamics around the sparkplug. Basically it becomes a heat sink around the sparkplug.



I thought that was a pretty sharp observation.



man I feel so much better!

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[ether_joe]

well good news all round then - a heliocore fix, four new sparkplugs, and I'm good to go. < $300 it cost me - and, I found a great Pcar mechanic in SF!



took the car on about a 75 mile trip last night and she was just fine.



all's well that ends well then. . . back in business! man I'm so relieved. <img src="/forum/images/smilies/968/cool.gif" class="smilie" alt="" />

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[ds968]

Good to hear the news, and not that $ 300 is easily overlooked but in light of what could have been a much, much more expensive problem, this is a pretty decent outcome . Cool ! And a good mechanic find as a bonus on top of it all <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" /> Hey, you should give him a ride to the Paso run this Saturday in case my car, or anyone elses' breaks down on the trip <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" />

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[RPM]

Great outcome to a scary problem!

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[ether_joe]

one thing I did notice. . . there is a nice 3" ding-crease in my hood where the sparkplug wire popped out. and some nasty black grime, I expect from the unburnt fuel for the 20s or so it took me to get to the shoulder.



Well not so noticeable as the power steering reservoir ding, and looks very fixable by a PDR guy.

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[ron1688]

[quote name='ether_joe' post='36197' date='May 31 2007, 08:35 AM']well good news all round then - a heliocore fix, four new sparkplugs, and I'm good to go. < $300 it cost me - and, I found a great Pcar mechanic in SF!



took the car on about a 75 mile trip last night and she was just fine.



all's well that ends well then. . . back in business! man I'm so relieved. <img src="/forum/images/smilies/968/cool.gif" class="smilie" alt="" />[/quote]





So what's the name of the new mechanic and where are they located?

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[ether_joe]

Vanguard Motors on 10th street. Owner's name is Gary.





Vanguard Motors

350 10th St

San Francisco, CA 94103

(415) 255-8450





I'm gonna post this in the mechanic recommendations section also.

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[VGM911]

[quote name='Renalicious' post='36060' date='May 27 2007, 08:01 PM']Doh, that sucks. I can't say I've ever heard of a spark plug socket becoming stripped, despite hearing stories of spark plugs being screwed in so tight to almost break tools.[/quote]



In the old days when I drove a 1963 VW Beetle, I remember the aluminum heads being "soft" enough for me to strip two plug holes. At that time, the heliocoil was the solution of choice.



I'm wondering if the aluminum heads of today's cars are any "harder" than they were in the old days. Thoughts, anyone?

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