Bad Glow Plugs

[Blzr6.2'83]

My truck had bad glow plugs when I got it, so I bought some quickheat self regulated glow plugs off ebay. I have a manual switch and only turned it on for 6-10 sec to start it on a cold morning. A few months after i bought them they went bad and it wont even start with WD-40. They went bad slowly, as if they went out one at a time, until they were all bad. Is there a certain voltage they should get or did I just get some bad products from ebay? What could cause them to go bad so quickly?
This is a link to the ones I got ebay plugs (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7984122148&category=33693&sspagename=WDVW)

[damork]

I would be very cautious with glow plugs. I replaced my originals with AC60G Delcos and the only others I would trust are the type Kennedy sells, or at least a well known name brand. I've made it over 125k with mine and it still starts like the day I installed them. Not sure about the ebay products.

[Barry Nave]

2 year replacement. Send them back.
Myself,I'd need them sooner than later.
Sounds like the company that makes these plug know what there doing. Made in the USA is a good thing if they work as they say. Price for the plugs look good.
I have the Bosch glow plugs, going on 80K.
Even summer mornings they will cycle. This helps for quick starts.

[KallyI]

Just for information's sake, I bought glow plugs like this, from this supplier, on ebay in January this year, and have had absolutely no problem with them: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33693&item=7983538201&rd=1&ssPageName=WDVW
Hope you get some satisfaction from your supplier.

[Blzr6.2'83]

Could there be something causing them to go bad so quickly though? I don't want to keep getting new ones every few months if there is a problem.

[Kennedy]

Does the surface of the plug look smooth or orange peel/pitted?

[Blzr6.2'83]

Not sure. I will check them in the morning.

[Blzr6.2'83]

They have orange peel and are rough. What does it mean?