How to: Replace thermostat with metal one!

Sorry for the lack of pictures but I will write out each step to do, since its easy and considering that I just did it today!

1. Open hood
2. Locate Thermostat (To the left near belts)
3. Remove the clamp on the hose coming from the radiator. (Will be tough but just work it off.
4. Also remove the clamp around the hose coming from the engine and be careful YOU WILL lose some fluid and i lost more than I thought and had to get some antifreeze, so keep some on hand.
5. Remove the bolts holding the plastic thermostat housing on to the engine block. It has two 1/2mm bolts on it and you will need a extension on your ratchet. (Fluid will come out here as well, be careful and don't do this when its hot!
6. Once the bolts are out remove the old housing and make sure you get the old gasket off as well.
And to install the new one just reverse the order and there you have it! New thermostat housing and no more worrying about that plastic one cracking driving down the road!!


**Some things I did adn things to consider!**
The smaller hose didn't like me using the clamp so I had to buy a hose clamp and tighten it down like that! Also have something to catch the fluid so it doesn't go all over the ground and ruin water (bad thing!). Make sure the hose clamp (if you use one) is out of the way of the thermostat and the upper hose or the thermostat will not tighten! (learned the frustrating way!) Other than that it was very easy, not problems at all, all day and now no more worrying! Hope this made since? Sorry for no pictures any questions just ask and I will try and answer

Have a good day guys/girls!

Here are some pictures of when I did mine a while back:

The thermostat is in the lower left:
Attachment 9039
Thermostat removed:
Attachment 9036
Old thermostat:
Attachment 9037
Close-up of new one put on:
Attachment 9038

The clamps are a pain in the ass to deal with, so do not let them come off the hoses if you are reusing them. Make sure you keep a close eye on your temperature gauge and check your coolant levels for the next few days after putting the new one on. Also, this is a good time to flush your coolant if it is due.

Link to the metal one I bought: Dorman Thermostat Housing Upgraded Design Metal for Aveo 5 Lanos Wave 1 6L | eBay

I missed this thread. Nice write up!

The only thing I would add is to have a 2" pipe clamp handy. I found that the spring clamp did not work as well. So I had to put a pipe clam on. So if you replace the t-stat, just replace that clamp right away.

When I was working on my '08 I this weekend (different repair) I was surprised to see a metal thermostat housing. I thought the originals were always plastic. It's possible it was replaced before I bought it in 2012 with 47,000, but that seems pretty early for a thermostat fail. Were some original thermostat housings metal?

They replaced the plastic ones with metal ones in 2007 I believe.

Thanks for posting this thread. I had to tackle this job in a parking lot yesterday. It took about an hour. The $30 hose clamp tool below that I happened to have in my tool box made handling the hose clamps a breeze. I purchased the replacement water outlet assembly from the local NAPA store, needed one now and they had it in stock for $34. Good quality and included all gaskets and thermostat. Also installed a new radiator hose ($13), figuring I may as well while I'm in there, although even after 12 years, the old one looked good. The plastic tube broke off inside the head, and I spent and extra 15 minutes extracting it. The plastic was very soft and easy to split with a screw driver. I also had to clear some corrosion from the head to fit the replacement tube.

Although it overheated for maybe a minute, the engine or head gasket doesn't appear to be damaged. I will be keeping tabs on the coolant level. Next job is thinking about the valve cover gaskets as a small leak has a tendency to drop on the exhaust manifold making some smoke. Very small leak. Only 80,000 miles on this 2004, which has been in the family since new.

Be sure you get the correct parts. I was given a thermostat only and the wrong one from the auto store. For the 2008 aveo i had to replace the assembly as one unit with the thermostat seated in the center. A simple fix turned into broken parts so beware double check what you buy. We stripped the casing then almost had to rethread it. A bolt snapped after taking it apart multiple times from being given the incorrect thermostat and bolts. Save yourself the headaches be careful.

hey that small hose defiantly a bugger i did the same changed the clamp...that small hose do u know the name of it want to replace with a new one noticed a small crack in it ..cheers.

I have a question...

My wife has a 2009 Aveo5 LT, and the thermostat is stuck, so I need to replace it. Does the '09 use the plastic housing, or is it metal? I've checked Rock Auto for parts, and came up with this:More Information for ACDELCO 55597008

Just wanted to make sure this was the right part before I continued.

Thanks for your time!

Looks like metal to me.

Okay, another question: Is there a thermostat out there that is cooler than 221? Or are they all 221 degrees?

Also watch when trying to use factory bolts into steel housing.Mine had built-in washers that send the bolt off-center and cross-threaded into one hole. Had to re-tap bolt hole in head and got some replacement bolts and ground one edge off a new washer to not hit the housing.

My car is an '09 LT. The engine light came on, it showed thermostat/ temp sensor failure. I went and bought a thermostat from Oreilly's for like $90. Then I found out the housing/ water outlet attached to the engine block was made of plastic. I put the new part on and drove a bit, then stopped at the gas station to check for leaks. Sure enough she was leaking. I grabbed my ratchet and tried to carefully tighten the thermostat, and just as the leak stopped, the plastic housing cracked. coolant started streaming out. I quickly shut the hood and drove around the corner to my driveway and shut the car down. Nobody within 30 miles had the part I needed. I looked on Rock Auto and Ebay. Everything was plastic. Then I saw the same part for the 2012 Sonic, it looked exactly the same, but was made of metal. I blew up both the photos, everything lined up, bolt pattern, gasket shapes, hose connections. Get this the metal one on ebay was way cheaper too! I took a gamble and got it for around $40. Here is the listing: Thermostat New Chevy Chevrolet Cruze Sonic 2012-2015 | eBay
It came in a few days. I cleaned the contact surfaces, bolted on the part, connected the sensors, clamped the hoses, refilled the coolant, crossed my fingers, and started the car. It worked great! No leaks. I drove to the movies and out to get Chinese takeout on a hot afternoon with no issues. Tomorrow I have a 45 minute commute so I will update this post after returning from a longer drive.

Broken Housing
Attachment 11080
A closer View
Attachment 11081
The new part arrived
Attachment 11082
All hooked up
Attachment 11083
Engine running, no leaks
Attachment 11084

***UPDATE***

The newer thermostat and sensors run cooler; the computer does not like that. It activated the check engine light with a thermostat/ temperature fault. Detailed message stated that coolant temperature was lower than normal. My plan is to swap in my old temperature sensor, see if that works. If not, I'll put on the thermostat/ sensor I bought originally. I'll update again with what works out.

***Final Update***
I did some research on modern engines and thermostats. It would be too much of a hassle to reprogram the computer and tune the engine to use a cooler thermostat and temp sensors. That being said, I went ahead used the new thermostat I originally bought from O'Reilly's, bolted it to the new metal housing from ebay, and used the temp sensors from the old plastic housing. I used the newer o-rings because they were in much better shape. Everything works great. After a couple 45 minute commutes to work I noticed a definite improvement in engine performance.

Thank you for reading, I hope my experience helps.

When buying metal thermostat from auto zone for my 08 AVEO notchback (sedan) there were no gaskets or O rings.
Metal to metal will leak. Comments welcomed.....

Attachment 12166
there should be an o ring at the back of the housing. Felpro number 35862.
BUT it should have been in the box you bought. Go back and tell them.