Discussion in '1982-Present GM Diesel' started by four_by_ken, Oct 7, 2002.
Ok, whats the whole story about mushroomed glow plugs? What is the cause and all?
Well they swell up at the tip when they burn out (sometimes), Not really sure why they swell though /forums/images/graemlins/confused.gif
The newer plugs, like the 60G, are Positive Temperature Control and don't burn out/mushroom .
The tips of some glowplugs swell (mushroom) when subjected to too long of a glow time, typically caused by over-riding the stock controller with a manual button or switch. While having manual control over glow plugs is fine, a lot of guys tend to hold the switch too long, burning the plugs up.
This situation can also be caused by a faulty controller which shorts out and leaves the plugs on indefinitely.
The older 8G, 9G, and 11G plugs were all subject to swelling. Supposedly, the 60G plus are not. I have 60G plugs in my truck now, and they have lasted longer than any other plug I've used yet.
The swollen plug causes a problem when you go to remove it. It jams in the glow plug hole, and in the worst case, the tip breaks off and falls down into the pre-combustion chamber. This requires removal of the injector in order to fish out the broken pieces.
I had a tip break off, but it hasn't fallen into the pre combustion chamber. I can really remove it from the injector hole? This is great news to a guy who was just pricing head gaskets! =)
Not only possible, but down right quick!... 15 minutes after breaking the tip off the glow plug, I was threading the new glowplug in and trying to start the truck.
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