Stripped Spark Plug Thread

[thebadleys]

Good afternoon All,

Well, ready for a trip tomorrow with SWMBO to visit daughter and family who are on holiday on the east coast near Filey and yesterday bit of misfire / uneven running.

So checked all wires, connections, leads, etc.and as I have not replaced the spark plugs since I got the car, just cleaned them but found most difficult to remove so re-tapped threads all has been OK for 3500 miles

Ordered new plugs from Peter @LD, arrived today so set about the job, changed righthand bank no problems (bit of copperslip when I last checked them) however, No 2 on the LH bank appeared "loose" then tight, then loose ! when removed bits of thread apparent on the spark plug. Ran my tap up the thread (it taps from inside out) and it was obvious that the thread was gone.

So , can helicoils be fitted without removing the head ? and if possible has anyone any recommendation as to the type of kits available.

Bay seems to offer cheap answers http://www.ebay.co.uk/itm/Spark-Plug...item419c43578f what I think should be better quality items http://www.ebay.co.uk/itm/M14-x-1-25...item19d8d49d9d

Your help and advice would be appreciated as I was hoping to get out and about this month having just, what I thought was finishing touch for this year fitted new wheels and tyres!

Thanks in advance

[Arbman Al]

Hi Nigel

Not had to do this job yet thank goodness, but have heard mention of timeserts rather than helicoil in this situation.

Cheers....Al

[jleyton]

I've done this ok on mine with the head in place - nerve racking but do-able.

I used a kit kindly loaned by DJT so don't remember the make and was torn between the differing advice as to whether to do it 'dry' and then vacuum out or stuff a greasy rag down the plug hole first. I'm still not sure which way is best

Sorry not to give you exact answers but I hope it's reassuring to know it can be done.

Cheers

Julian

[thebadleys]

I've done this ok on mine with the head in place - nerve racking but do-able.

I used a kit kindly loaned by DJT so don't remember the make and was torn between the differing advice as to whether to do it 'dry' and then vacuum out or stuff a greasy rag down the plug hole first. I'm still not sure which way is best

Sorry not to give you exact answers but I hope it's reassuring to know it can be done.

Cheers

Julian

Thanks Julian for the reassurance, seriously p#####d off car seemed to be running so well and after going over the car the only job that I thought might be need was prop balance/replacement to make the drive even better.

Ah well, these things happen and, in the great scheme it's not really that bad, we lost a friend today to cancer, whom we'd known for over 50 years (since we went to school), diagnosed 4 weeks ago died this morning just 65.

[LAMBRETTLAD]

Sorry to hear of your loss ,it put's things into perspective

[nib]

Ah well, these things happen and, in the great scheme it's not really that bad, we lost a friend today to cancer, whom we'd known for over 50 years (since we went to school), diagnosed 4 weeks ago died this morning just 65.

Sorry to hear that Nigel.
One small blessing there was not months of suffering.
Take care
Mark

[thebadleys]

Thanks Mark ,Alex.

Looking at something like this to repair, http://www.ebay.co.uk/itm/M14-x-1-25...item19d8d49d9d ,

Has anyone used this type before, does the tap "lead' into the existing thread?

[mole42]

There's usually a twist drill in the kit to make a clean hole to tap into.

[v8ken]

Hi Nigel,
Sorry to hear of your loss of your friend.
If I were close by,I'd offer to do your helicoil,I did mine and it makes it,in my opinion, a stronger than original job.
The kit I used said that the drill needn't be used when going into aluminium,so I tapped straight into it,sucked the filings out(with a small tube taped onto the vacuum nozzle),then inserted the coil and lastly carefully broke off the tab.
I wouldn't worry too much about any bits of aluminium in the bores,they'll soon disappear out of the exhaust valves and are soft metal anyway.
Regards Ken.

[thebadleys]

Hi Nigel,
Sorry to hear of your loss of your friend.
If I were close by,I'd offer to do your helicoil,I did mine and it makes it,in my opinion, a stronger than original job.
The kit I used said that the drill needn't be used when going into aluminium,so I tapped straight into it,sucked the filings out(with a small tube taped onto the vacuum nozzle),then inserted the coil and lastly carefully broke off the tab.
I wouldn't worry too much about any bits of aluminium in the bores,they'll soon disappear out of the exhaust valves and are soft metal anyway.
Regards Ken.

Thanks Ken,

I'm quite happy to have a go myself, my concern is getting the right kit, which kit did you use, I'm now looking at this http://www.frost.co.uk/m14-armacoil-...epair-kit.html as SOC members get 12% so it would be £49.

[DJT]

You won't need a twist drill to open out the holes in Stag heads. The kit I have (and lent to Julian) is a V-Coil one, similar to the first (eBay) link you posted. It worked OK, but you do need to seal the insert into the thread using an appropriate thread locking compound. The Timesert kit is supposed to be the best as it opens out the bottom threads to lock the insert in place.

[thebadleys]

You won't need a twist drill to open out the holes in Stag heads. The kit I have (and lent to Julian) is a V-Coil one, similar to the first (eBay) link you posted. It worked OK, but you do need to seal the insert into the thread using an appropriate thread locking compound. The Timesert kit is supposed to be the best as it opens out the bottom threads to lock the insert in place.

Thanks Dave,

Looked at Timesert kits, only supplier I could find sell the kit at £170 plus inserts at £4.95 each.

As Julian appears to have had no problems I will sort out either the V Coil or the one from Frost as I can collect from them.

Im away tomorrow and Friday but would like to get the job done this weekend is possible.

[Hughesy]

I used Timesert as they do lock the thread as recommended by the mobile thread repair service guy I used to do it. He came around in his van and did the job in about 20 minutes. Cost about AU$120. Maybe worth checking out who does this in your area? Craig

[thebadleys]

I used Timesert as they do lock the thread as recommended by the mobile thread repair service guy I used to do it. He came around in his van and did the job in about 20 minutes. Cost about AU$120. Maybe worth checking out who does this in your area? Craig

Hi Craig,

Looked at Timesert and they are difficult to obtain at locally to me and the cost is about £170 plus inserts. I have looked on Google for mobile repairers but unable to find anyone, plenty of engineers will do it, with the head off so I don't want to go that route at the moment as I fear this could create its own problems.

Thanks for your input.

Nigel

[thebadleys]

Well, that's b######d it, the Armacoil kit I was going to get from Frost is apparently discontinued, despite their web site saying they have stock!! good job I checked before making a detour on our trip away, SWMBO would not have been amused.

Back to the drawing board.