Author Topic: Plug thread repair  (Read 335 times)

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AdrianS

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Plug thread repair
« on: 25 April, 2021, 08:50:03 »
Plug thread on my B40 is looking a bit iffy and feel that itís going to fail soon.
I suppose the best advice is to take the head off and get the local engineering firm to fit a helicoil.
Looking online there are several diy methods to do it, some leaving the head on.
Any advice from those who have suffered this?

courtney

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Re: Plug thread repair
« Reply #1 on: 25 April, 2021, 12:26:22 »
I've heard of doing it with the head on but I'd say it's not worth the risk of having anything dropping into the motor.

I think Timeserts are supposed to be better than helicoils for that kind of thing. They're a little more expensive but a better fix long term. Might not be too much more of your local workshop has the kit but if you're doing it yourself then helicoil is cheaper.

A classic internet forum topic: timesert vs helicoil
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LightningAndStarfire

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Re: Plug thread repair
« Reply #2 on: 25 April, 2021, 14:52:44 »
I did my Audi S4 with the head in place. Had the piston at tdc and with a powerful vacuum cleaner and a hose sucked up swarf. It worked.

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Re: Plug thread repair
« Reply #3 on: 25 April, 2021, 17:01:34 »
I agree with Blue Star on both counts.  That it should be completed with the head removed and that the better (but more expensive) item is Time Sert.  As Blue Star says this kit is slightly more expensive but to me it is more professional.  I have used both makes and have found the Time Sert one the best.  That is not to say Heli Coil would not do the job but Time-Sert instructions explains how to do the job in more detail.


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Re: Plug thread repair
« Reply #4 on: 25 April, 2021, 17:11:18 »
I agree with Blue Star on both counts.  That it should be completed with the head removed and that the better (but more expensive) item is Time Sert.  As Blue Star says this kit is slightly more expensive but to me it is more professional.  I have used both makes and have found the Time Sert one the best.  That is not to say Heli Coil would not do the job but Time-Sert instructions explains how to do the job in more detail.

Apologies courtney for renaming you as Blue Star on the above.  Its an age thing.

chaz

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Re: Plug thread repair
« Reply #5 on: 03 May, 2021, 21:08:04 »
personally, my choice...
the expensive way. do it properly first time.
head off, and open out the hole and fit an ally bush then weld .
saves the chance of any leaks past helicoils and possible loosening or cross threading the inserts in the future.

this comes from an engineering background of railway brake castings , we never use helicoils or inserts on oil or air/vacuum applications, only on fastening holes .