Advice on plug change problem
 

Last time the V8 was in for a service and MOT I was informed they couldn't change the spark plugs because the 'bolts just kept turning.' I was a bit puzzled but the car passed and was running well so I didn't follow up :getmecoat: A few misfire issues in the last two weeks prompted me to change the plugs myself and install MSD's and have good look over the engine compartment.
Some kind person has overtorqued three of the bolts holding in the coil packs and either stripped the brass thread insert/crossed the thread or stripped the insert within the plastic inlet manifold housing. I got the other five off normally, but three are just rotating. Been using the same garage for some years now. The guilty party must have known what they did and just swept it under the carpet :mad:
Any suggestions welcome.

plug change
 

I think I would try and prise out the bolt complete with the brass ferrule or at least until I could get enough purchase with a long nose pliers to hold the ferrule and slacken off the bolt, you could also try gripping the head of the bolt with "mole grips" or locking pliers and pull it out.
When successful either get new ferrules made of a slightly larger outside diameter and knurled or replace the originals with araldite and don't over tighten the bolts.
Hope this helps.
Nigel

Superglue is also a useful way of fixing a rotating insert. Works on Tourer rear lamp fixings by the way.

Found this interesting link
https://mustangforums.com/forum/4-6l...tally-fed.html

I'm leaning towards cutting off the heads of the three stuck bolts and then sliding the cop off the stem. Might try to carefully infiltrate some superglue first though I did spray liberally with WD40 yesterday. Will need a good clean out before trying the superglue on perhaps one of them.

I couldn’t think of a way to use superglue in such a confined space without risking gluing the wrong thing. Ended up putting a 7mm socket on a drill and spinning the cop bolt until it heated up the insert which then just pulled out. Really effective method as suggested in a Mustang forum. Got all three of the seized ones out. (I just couldn’t get anywhere with prising/leveraging) Sprayed the seized inserts on the three cops on the bench with de -block oil, but they are properly seized, possibly cross -threaded, so new inserts will be needed. Need to work out the thread size/type on the COP bolts before ordering new brass inserts. https://uploads.tapatalk-cdn.com/202...c12e79ec14.jpg
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As it may have a hairline crack in the manifold now, will you be replacing that while you're at it?

I don't think I've got any cracks. I did consider a manifold upgrade. I saw a You Tube video where an upgrade was done, and apart from the extra work it looked higher and unlikely to fit under the bonnet. I've noted the three COP brass inserts are M5 0.8 so those are on order. I'll araldite them in or similar and should have no leaks when finished. Might invest in a cheap smoke machine to test everything after assembly if any issues present.

Finally found time to finish the job. Used M5 0.8 x 10mm brass inserts from Amazon. Used the old securing bolts to keep them lined up while the glue set.https://uploads.tapatalk-cdn.com/202...4b976a01b4.jpg


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Used compressed air to clean the plug wells. Then a touch of de-block oil for 10 mins. The plugs were really tight but they all came out OK.


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