Spark Plug Stuck: Worn Hex Head.
 

On Sunday afternoon, I was doing routine Spark Plug replacement, 40k or so on my 05 4.4i N62 engine.

Cylinder 4, need confirmation, close to the driver's side with the least clearance my 5/8" won't grab anything. So I couldn't get it out. Rest of plugs I replaced it with ease. Put them back together now cylinder misfires....

I used the giant dentist mirror and flash light to see what's going on and I was able to to the plug is in there.

I ended up bringing it to a local German Mechanic Store, the older gentleman took a look at it with better flash light with his helper and diagnosed that "THE HEX HEAD HAS WORN OUT and NOTHING OTHER THAN PULLING ENGINE APART CHASE OUT FROM INSIDE WILL HELP.."

It was like a DEATH SENTENCE to my beloved(!?) X5. I have done some extensive web search but not much I could try. Smaller sockets, Kroil Pernetrating oil, perhaps break the head and use screw extracting tool?

On my previous E46 I was able to pull out plug when the top broke off but this time I have a worse clearance, and the top is still intact.

Any suggestions?

First, I would try to verify that diagnosis yourself (or take it somewhere else to have verified). It would take a lot of abuse to round off the body of a plug and it's my guess that damaging the the threads in the aluminum head would occur first.

Second, if this were truly the case, you can purchase (or locate a shop that has) what's called a bolt extractor. They are essentially a socket, and you want be sure to request a deep socket. Example of a kit: Sears: Online department store featuring appliances, tools, fitness equipment and more

Thanks for the quick reply.
The local mechanic who looked at it said, he has never seen anything like it. I wanted to use borescope (endoscope) to confirm, but he didn't use one.
I agree with your logic thread should go bad first... WD 40 didn't help I had nothing to grab onto, and also never used a power tool to strip anything.

I am running to Sears for bolt extraction tool. Will keep you posted.

+1 above

You need a set of deep, 12 point sockets. You need to find one that is slightly smaller than the hex. Then take a hammer and hammer it onto the plug. You should be able to remove this without taking the engine apart. I can't see you needing to take the motor apart because of something like this. Go find a Russian mechanic. #1 problem solvers in my book.

we are nice people, you know!?

I do know. Kak dela.

That was my second option to try out slightly smaller 12pt deep sockets, 15 mm, 14 mm. (Since 5/8 being 15.7 mm) Irwin BoltGrip is on my way from amazon.com I am gonna try that first.

I don't know any Russian Mechanics in my area. It was a older GERMAN MECHANIC who made that suggestion to take the motor apart. N62 Engine has a plastic nipple (rubber tube extension which is not connected to anywhere in front of the radiator) that I believe it is for vent. He also suggested some part is missing because of that. I don't believe him much despite of his national origin.

Thanks for the suggestion.

I like this idea!

Just ordered a Cheap Borescope from eBay. ($44) Will upload pictures as soon I get hands on. Thanks again.

You're correct ab the vent tube. Not that it makes him a bad mechanic for not knowing, but he has certainly not spent a lot of time with this motor. Looking elsewhere is a good idea.

Hamming on a slightly smaller socket is going to be your best bet. Good luck, it can be incredibly frustrating to remove anything rounding off in a deep socket such as a spark plug, but it's very sweet when you have success!

WHY ?
 

Why did you change the plugs ?

The spark plugs are good for 100K, why change them so soon?
In any case, THIS IS A VERY IMPORTANT STEP, prior to removing the BAD plug,
insert a magnet down the spark plug well to pick up any metal shavings
that may have collected. This should prevent any future problems with that cylinder.

to get better cleaerance, remove the two nuts that holds the cabin filter housing and remove the housing. you should be able to almost look straight into the plug.

Problem Solved.
 

Thanks for chipping in folks!! :)

What Helped: a List of Magic Workers
1. Kroil Oil (WD40 could kiss Kroil's a$$)
2. Irwin Bolt Extractor

What didn't help:
1. El Cheapo EndoScope ($30 from eBay) Takes pictures and videos well though
2. Local German Mechanics...

It turned out the hex-head wasn't damaged after all, which is very strange. But myself and the the mechanics couldn't get any grip with 5/8" socket. As you can see you could see the chip where Bolt extractor left the bite marks.

3" vertical clearance didn't help either. Thanks again all.

Glad you got it out finally!

fishy?
 

That plug appears to look fine to me wow !! add that socket to Your collection of stuff you will never use agine, but might someday HAHAHAH

Can't agree more. Hahaha

I don't get how your German mech couldn't get that out, really odd if you ask me. I bet it was a function of wrong or cracked socket.

Doesn't matter what ethnicity the mechanic is. Doesn't look like the socket was ever on the plug, as there are no marks. Just seems like incompetence.

It wasn't about ethnicity, but about the fact that he was german car knowing mech. I agree with you though.