if you try to melt it at the threads, you'll possibly make it stick harder. but if the dipstick is removed, then you have a hole in the center? use an EZ out and twist it out. yo might try heating
the tube lower down -away from the plastic plug
. As mentioned plastic expands more than metal, with heat...making it get tighter in the threads. But when the engine
is at its coolest...early AM...using a heat gun, warm the dipstick tube down low...say at the point it enters the tranny housing. the metal will expand slightly and loosen around the plug
. You could also use a flat thin piece of metal...like a butter knife...heat it and melt it into the hole in the center making slots on either side of the hole then turn it out like a screw.
Like I said, that was a pretty bad design flaw. When removing plastic plugs in warm/hot machines I usually cool the plug, by blowing on it, before reinstalling it, to keep from damaging the threads. If it's tight when screwing it in I stop and cool it some more. It will screw right in then. lubing the threads doesn't help. Besides after a while it thickens and bonds it to the hole, causing damage to the threads of the plastic.
I'll say it again BAD DESIGN!!! I don't think it was the idea of an engineer
...unless they were on the board of directors and was trying to pinch a half cent.