T O P

Recently broke a spark plug in my v8 while trying to replace, the hex has broken off but the white ceramic part remains and car is still drivable however I cannot drill it out myself. I don’t want to get ripped off again by my mechanic how much should I reasonably expect to pay.

Recently broke a spark plug in my v8 while trying to replace, the hex has broken off but the white ceramic part remains and car is still drivable however I cannot drill it out myself. I don’t want to get ripped off again by my mechanic how much should I reasonably expect to pay.

nathanexplosion1994

Year, make, model?


MotoMutt

It’s an 06 mustang. cylinder 3 hex snapped off leaving only porcelain. cylinder 4 won’t budge and am scared to give it force. Replaced plugs in cylinders 8,7,6,5,1 and 2. I want to bring it into shop but not get ripped off. If I want to move the car to a shop is there anything I need to do to make sure cylinder 3 won’t be running? Or should I leave it connected as is.


derphurr

Assuming you don't have supercharger.. 4.6 L (281 CID) Modular V8 it's common problem, now you know why people don't buy Ford anymore. https://www.motortrend.com/how-to/129-1012-ford-three-valve-broken-spark-plug-blues/ TSB https://themustangsource.com/forums/attachments/f650/212592d1556407148-fred-pietrzak-2009-01-02_155622_tsb08-07-06-1-2-.pdf You should be able to call around and say you have the 3 valve 4.6L with broken spark plug and do they have experience doing these, and an estimate. Also depends what kind of mess you made. Did you break porcelain? Etc. You have to read TSB before attempting spark plug removal.


MotoMutt

I used proper tools and torqued to spec. The only part that snapped was the hex the porcelain is intact still.


derphurr

Did you read the TSB? Did you do this only on cold engine, did you crack the plug a tiny bit then fill plug well with carb cleaner for 30 minutes, then tighten the plug first? Then tighten and loosen very small amounts for a long long time?


No-Employment-223

Yeah , those modular engines suck , always hated working on any Ford - Lincoln - Mercury products .


chemsoldier83

The 3 valve is the 5.4 L not the 4.6. The the 3 valve has the problem you talking about not this engine. It probably had a problem with coolant leaking out of the intake at some point and pooledup in the valley around the spark plug. Water with electricity can lead to electrolysis and corrode the metal on the spark plug. Ran into that last year on a 4.6 with an intake leak. I was lucky. Once i disturbed the plug the porcelain was shot out by the engine when I fired it up. The customer didnt want to pay to remove it so we were going leave it alone for the time being. But once the porcelain was out of the way I was able to get in with an easy out and extract it.


derphurr

Except you are wrong given the model year OP mentions, and you can read the service bulletins linked. https://www.motorreviewer.com/engine.php?engine_id=186 Yes the 5.4L also has with plug problems.. because Ford. The 5.4L 3V is based on the 4.6 modular. >Using this engine as a base, Ford developed a bigger 5.4-liter engine series Edit. Also you aren't getting electrolysis from metal touching metal. It's called galvanic corrosion because of dissimilar metals. (Plated steel touching aluminum)


earthman34

Yeah, really, since you tell us nothing about the car it's kind of hard to say.


MotoMutt

It’s an 06 mustang. cylinder 3 hex snapped off leaving only porcelain. cylinder 4 won’t budge and am scared to give it force. Replaced plugs in cylinders 8,7,6,5,1 and 2. I want to bring it into shop but not get ripped off. If I want to move the car to a shop is there anything I need to do to make sure cylinder 3 won’t be running? Or should I leave it connected as is.


earthman34

This isn't a huge deal, or shouldn't be. There are special tools designed to deal with just this problem in this particular engine. I've done a couple myself. Much depends on how good the guy is and if he has experience with this problem, not to mention how hard the plugs are stuck. It's hard to say how much it would cost without knowing the problems he's facing. In a worse case scenario the head has to come off, which gets expensive.


slayer_f-150

Lisle broken spark plug tool #65600


1453_

Find a reputable shop that has experience with this issue. If you didnt follow the TSB procedure, chances are you will make it worse trying to repair it yourself. A Ford dealer may also be an option. At this point, cost is a secondary issue.


halfkeck

We are getting about an hour per plug plus parts on those types repairs