Thermostat failure - common problem?

[airman jack]

So I just had 2 CEL's within a week indicating virtually the same problem. My dealership is now telling me that the problem is the thermostat being stuck open, so the engine isn't getting up to temperature fast enough, and this will definitely be a problem once winter rolls around. They also tell me it'll be about $260 to replace the thermostat.

Have you guys heard of the thermostat failing like this before?

Is it hard to replace a thermostat on your own?

Also, the dealership rebuilt my engine a few thousand km ago, and they insist that nothing they did when the pulled out the engine could have damaged the thermostat. I've got about 103000km and the service manager, who I think is a fairly good dude, seems to think that this is about the lifespan of a thermostat.

Thanks for any info or help!

[ShaleZoom3]

I know its more difficult to remove/install the 3's thermostat due to it being different then most cars. Hopefully somebody more knowledgeable can chime in......I want to say because its located in the block.

[ionorick]

it took me roughly 2 hours to replace the thermostate not knowing what to do. Overall its very simple just very tight on space. I had the same problem and it only cost me the thermastat and some coolant about 50 bucks to do myself

[ViperKillerWannabe]

It shouldn't be too difficult to do yourself. Just find the upper radiator hose and follow it to where it goes into the block. You should see a "bubble" there with a bolt on either side. That's the thermostat housing. Undo the bolts, pop out the old t-stat, throw the new one in, replace the gaskets and put it all back together and you're done.

[KrisZ]

On the 3 the thermostat is located under the intake manifold, you can see it to the right of the belt tensioner pulley. You can probably access it from underneath, it looks awkward but doable.

[airman jack]

I have access to a lift and proper coolant disposal facilities, so that should make things a bit easier! The dealership reset the CEL and it hasn't come back on yet. Really, of the two failure modes for a thermostat, this one is the "good" one, so I'm going to take my time before I fix this.

[azazel1024]

I've never had to replace one before, but I wouldn't be saddened if one went out at 103k km. They are fairly cheap and the job isn't that hard, just difficult to get to since you have to go at it from underneath.

A thermostat is generally just a wax filled valve (okay cylinder). Coolant heats up and the wax softens pushing the valve open. Once it cools enough the wax hardens pulling the valve back closed.
-Matt

[airman jack]

Heh.. they're cheap, unless you pay someone else to do it at $105/hr labour!

[KrisZ]

If someone live in a hot climate and the thermostat fails stuck open the there is probably no reason to change it as the car will worm up as usual. If yoy have winters than better change it before as you will have minimal heat on the highway.

[roman86s]

Same thing happend to me! Went to the dealer, and got it fixed for $78