Tight glowplug 1.9 Peugeot - Crinkly Dave
Any ideas on releasing tight glow plug (in for 189k) from head.

I have started repetitive soaking in plus gas, and thought of applying heat to the exposed end of the glow plug, and/or cold using one of the plumber kits.

(Quick 5 minute job before the pub, without using the big toolkit, I thought. Present damage so far:- the flexible drive to my "Indoor" socket set, the socket which fell off and jammed behind the alternator, the harden spilloff pipe that snapped (thank god for the spare engine), the snapped hardened breather pipe (the ones you can't get anymore)

of course the plugs are easy to get at on these old non-turbo engines, except for the one behind the diesel pipes for 3 &4. Guess which one has a resistance of 4Mohm and is stuck.......................)

One more soak in plus gas, and off to pub

Tight glowplug 1.9 Peugeot - wemyss
So many stories on this forum Dave about snapping one off and the work involved in having the head off or helicoils...
Will it start with three only?...if so I would leave it.
A forum search will give some ideas on how to remove it including your plus gas or similar.
Tight glowplug 1.9 Peugeot - dieselhead
My advise is to heat around the glowplug with a gas torch (keep away from the bottom of the head near the gasket and use a soft flame)..should be hot enough when the plus gas is smoking. Hitting the top of the plug with a hammer and drift might help loosen it but the heating is usually enough. Usual safety precautions apply!