Thermostat - New one failer right away

Recently I changed the thermostat in my wife's 2005 Aveo HB.
Reason was not becuase the OE one failed (the nice alluminum one that came originally in her car) but becuase I was in there anyway recently doing her timing belt, tensioners and pullies, water pump, and the serpentine so i figured the collant is out might as well change the thermostat. Stupid me bought the aftermarket one for $45.00 instead of the original OE replacement from GM for $120.00 (these the are prices in Canada).
Her car has 105,000 kilometers so I figured even though most of this stuff is working at the moment might as well change it all for preventative maintenance. Howver, the replacment thermostat I got was the cheap plastic one that I believe was discontinued by GM after failures in the 2004 model aveo's and of course the one I got is failing right away, just days after installing it I'm getting engine code P0128 for thermostat stuck open.
I'm going to return that cheap plastic one to my parts store and just re-install the old original alluminum one she had in her car. Probably will still end up just going to GM eventually and forking over the $120.00 to get a new alluminum one, just really sucks that the aftermarket ones are so cheaply made that they fail almost right away.

if you already had the aluminum one, you had no need to change it. And no need to replace it again if you put is back on.

The plastic one will fail very quickly if it is over torqued.

Thanks for the reply.
So I must have over tourqued the plastic one then.
I'll pull it off tonight and put back the original alluminum one then.
But really, don't feel the need to replace it even after 105,000 kms?
I just figured want to get her another 100,000 more km;s problem free so I'd change it to a new one, just didn't realize they for for that much $$ ...

Thanks again .. :)

Put the stock alluminum trhermostat back in on the weekend, left the battery unplugged over night, and sure enough no more engine code and temp is back to normal and maintaining at normal.

Thanks guys!

Luv this forum !!:p

the aluminum one will last the life of the engine, if you have a plastic one, i would replace it AT LEAST as often as the timing belt.