2.3 Petrol - Blew Spark Plug Out Of Head - Help, Please

[kleencat]

Hi everyone

 

I am a new member to this forum (or any forum, for that matter), so please forgive me if I do it all wrong.

 

Our 2003 Ford Galaxy 2.3 petrol just recently blew one of it's spark plugs out its place in the head.

 

A local garage suggested it was a very common problem for these engines and felt quite confident he could repair it without major overhaul, by filling a 'Helicoil' (don't know if I spelt that right).

 

However, he has made 2 attempts now and has been unsuccessful.  The last attempt has kept the plug in there (just), but it is definitely leaking compression and losing performance.

 

We have resigned ourselves to removing the head.  I will attempt it myself to save money.  But, what we would like to know, is what we should do once the head is removed.  Is it best to have it repaired?  Or replace it with one from breakers yard?  Or, will we have to bite the bullet, and buy a new one?

 

Any suggestions would be appreciated...

 

I would love to hear from anyone who has had a similar problem before, or has any tips or advice for us.  Also any advice on stripping down the engine and removing the Head would also be appreciated.

 

Many Thanks

[sparky Paul]

Can't recall seeing the problem on here before, so I don't think it's a common problem on the 2.3, but aluminium heads are more prone in general to thread corrosion and problems from over tightening.

 

Helicoiling a spark plug thread is a relatively straightforward procedure, and very successful if done correctly. It is easier to do with the head off, but it should be possible to do it in situ with the right kit, and some method of removing all swarf from the cylinder. The process involves re-tapping the hole with the special helicoil tap, then fitting the helicoil with a locking/sealing compound. The helicoil is a sprung steel coil which sits in the new thread, the inside forming the replacement thread for the plug.

 

Was the garage able to identify why the helicoil failed? Usually, problems are caused by incorrect fitting, e.g. lack of threadlock, or protrusion of the helicoil from the thread, defeating the spark plug crush seal. The 2.3 plugs are deep, but it should be possible to helicoil the threads successfully, with the right implements, and a bit of care.

 

Are you certain that the problems are due to the helicoil, and not debris from the helicoiling fouling the valves? I hope not.

 

If the head has been damaged by the failed helicoiling attempt, at least secondhand heads are relatively easy to come by.

Edited July 16, 2014 by sparky Paul

[Sladey]

Hi,

I don't know if you've done this yet, but i had a stripped thread in my 2.3 too. I fixed it by buying a thread replacement kit, it is not helicoil but a steel insert with a larger thread in the outside and a spark plug thread inside, the kit came with a tap/drill.

 

I did it with the head in the car, first I pulled out the helicoil, as someone had tried that before, then I covered the drill/tap tool in grease (to stop swarf dropping in the cylinder) then manually rotated the tool in to the head slowly ensuring it followed the old hole, I withdrew the tool every couple of turns and cleaned off the swarf applied more grease and continued until it was all the way through. I then degreased the hole and applied the locktite type compound supplied in the kit and screwed in the thread adapter using a spark plug as the insert tool (I used copper coat on the spark plug threads to ensure they would not seize in future. Job done! That was a year ago and no problems so far, besides Ford quoted me

[big wheel]

Well done Sladey,

A clear explanation on how to save 500 squid.

You don't have to be a motor mechanic sometimes to come up with a common sense answer.

We might ask you one day how to fix a stationary 50 year old Lister pump.