Seized plugs

[bossko]

Hi,

I just had my 172 serviced at a local garage unfortunately they were unable to remove the plugs as they were seized solid. The put the usual penetrating fluid on but to no avail. They reckoned the plugs had never been change and would not risk trying to remove them incase they snapped. Does anyone know of any garages that could remove the plugs if they did shear off. Two garages have said just leave them. And what cost is involved.

i live in the Northeast area near newcastle.

Cheers.

 

[MicKPM]

You've got two choices here:

Hit the plugs with a breaker bar or impact gun and hope they free without bringing the thread.

Replace the head.

If they do bring the thread you can timesert the plug Wells but the head should still be removed to do so.

 

[Dan@SJM]

As above, but with option 1, leave the engine running for about half an hour before dismantling of very quickly, it'll give you a better chance.

 

[Mr R.]

As Dan said, get the engine nice and hot.

It will give you a better chance as alloy expands faster than steel.
I always try to do it up 1st, then un-do.

Don't just go straight into un-do mode, un-do then tighten a bit then un-do until it feels ok/loose enough to un-do.