Weird Spark Plug Problem
 

Hi guys, I changed the plugs on my 2005, V6 today, with Bosch Platinum 4 spark plugs, and all went well, except for the center one on the driver's side. where the spark plug seems to only screw in half of the threads (from screwing it tight, and then taking it out again and look at the dielectric grease mark), The plug was installed to be as tight as it can be with out breaking it, so I'm not sure why it seems as though its only going in half way. I took the car for a drive after wards and it seems to run well, all cylinders running.

Any thoughts? I'd hate to have that spark plug shoot out on me in the future.

Thanks in advance!

Well guys, I cold started the car, turned off the radio, A/C, and just sat and listened to the motor for 5 minutes. There is definitely something wrong, and the engine is not idling as smooth as it used to, and there are the occasional pop sound coming from the cylinder. Therefore I think that particular spark plug is definitely not seated correctly. I don't want to force the plug in as I'm afraid of totally destroying the thread. What should I do guys? Should I try to tap the thread? or just take it to a shop and get it Helicoiled? And how much would it cost generally to fix a crossed thread?

Really gutted about this! Any help/suggestions greatly appreciated!!

Are you sure its even cross threaded could just be some dirt and grim on the threads.

cross threaded yeah that would suck, about the dirt and grim, you can get a thread chaser at autozone, advance etc and run it down and it will remove the gunk.

Yeah its definitely cross threaded! I tried to quick-fix it this morning, and I think its a little better, but down the track it definitely needs to be helicoiled.

What I did was:

1. Cleaned a couple of older spark plugs (The one-piece type! two piece would break to bits), remove the white plastic insulator part (break it off), and cover the threads with lots of thermal grease.

2. Slowly work the old plug into the crossed thread. the grease will catch majority of the metal shavings. Work in half a turn at a time, take the spark plug out, re-clean the threads and apply new grease.

3. Put the old plug back in, work in another half a turn, take it out and clean again...etc

4. Work until either satisfactory thread is achieved, or the old spark plug just wont go in any further (Which is my case).

5. Put the new plug in.

Using this technique, I managed to get the new spark plug in about 2/3 ~3/4 into the thread, so there's about 7~8 turns of threads holding it in. The fit is nice and firm now (feels tighter than the other 5), so hopefully this will last until my next monthly paycheck so I can get the head helicoiled.

Drivability: While driving, it totally unnoticeable, in fact the car drives great with the new oil and spark plugs. But when the car is warm and idling at ~700rpm, it has an occasional exhaust pop that wasn't there before the service (Noticeable only because I have Mac Boomtube). Now I'm not sure if its because of the new type of plugs (Old one was factory) or if its because of this particular plug sitting only 2/3 in.

What do you guys think? Do you think this can last for a few months until next time I need Plug change? or should I get it helicoiled as soon as moneyly possible?

Thanks for the help!

there is a heli-coil kit you can get at advance auto and it will only take 10 mins to fix your car and with out removing the head, I had the dreaded plug blow-out on my car. I'll find the part number for you.

Thanks man! I got a quote from a local shop, $160 for getting the helicoils in. If i can't fix it myself, then the car'll have to go into the shop.

Thanks again!

the part # is 5334-14 at your local advance auto, costs about 10$ and like I said 10 mins to fix. Use the insert in the middle and if you have more then one blowout/cross threaded you can buy extra insert there as well. here is a picture of it.

sorry, just checked AA and the price is $29.98, must have went up recently. still worth the price.

https://mustangboards.com/attachment...1&d=1225817320

btw, I have driven over 5000 miles without any issues, I just returned from ft hood mo and got 28-29 mpg @ 70mph. If you need some instructions just holla

also you need the red thread locker.

i was told by the sum peeps that bosch suck ass

Thanks man!! I got one of my friend to re-tap the thread for me, seems to hold fine now, so I might just run the car like this until the next plug change.

For real? I know pretty much nothing about spark plug qualities, but as far as I was told don't the different brands make stuff all differences these days?

ya just read this thread

https://mustangboards.com/v6-tech-fo...ark-plugs.html

NGk's are excellent plugs and cheap too.

Oh Shoot! should've done some more homework erh!:xself:

Oh well, next time I need plug change I'll go back to stock. Thanks though 3.8LMustang and everyone that helped out!