Thermostat housing broken, and "potential" blown or cracked head gasket! HELP

[Sweetygirl2312]

Hello guys,

My 2005 Chevy Aveo started to have white smoke under the hood when I was going home one month ago. I had it towed to a mechanic who said it was the thermostat housing that broke. 3 weeks later, I am experiencing engine overheating issues. I took it to the dealership, and they diagnosed a "potential" blown or cracked head gasket but they are NOT sure… Since they tried to sell me a new car right away, I am not sure they are trustworthy.
I thought that the head gasket issue was easy to diagnose??? Does anyone could give me advices to check if it's really a head gasket issue???
My first thought was the cooling system. How can I check it?
A little history of my car: I bought it in 2009 at 67,000 miles, and never had any problem until this thermostat housing issue. I changed the timing belt and water pump at 90,000 miles, and valve cover gasket, spark plugs, air filter this month along with the thermostat housing (metal, not plastic).
Even if the head gasket work is expensive, I feel like it's worth it to get it done since my car had no problem before but I would love Aveo experts opinions!
All your comments and suggestions are be much appreciated!
Happy Holidays!

[avguy]

.... Since they tried to sell me a new car right away, I am not sure they are trustworthy....

If it rattles, and is coiled up, then it's probably a rattlesnake.

Did you check the coolant level in the overflow tank before taking it to the stealership? Did it overheat at all during the period of time that you saw smoke (which I assume was steam) coming from under the hood? Do you see any sign of moisture on the engine or dripping from underneath? Do you see white smoke coming from the muffler after the vehicle is fully warmed-up? How is running now? (any loss of power or hesitation).

It is unfortunately possible there is a very slow leak from the T-stat replacement job which resulted in losing lots of coolant over time, and eventually caused the overheat. I know for certain this is possible because I've done this job a couple of times, and had this very slow leak that I needed to follow-up on and correct. A leak like this from a hose clamp can be so slow that the coolant burns off/evaporates and doesn't leave a noticable trace. The only way you can find it before it causes a problem is to observe the coolant level slowly going down in the overflow tank.
But it's also just as likely that the damage had already been done during the original T-stat housing problem, if the HG is in fact blown.

How about the mechanic who replaced the T-stat housing - did he seem ok to you? Do you know other people who have had work done by him? If you think the orginal mechanic is capable and reasonable, you might consider taking it back to him and see what he says. But do not suggest that he made the mistake I mentioned above, and don't mention your vist to the dealer either. Just say it's overheating, and he can run the tests required to determine if the HG is blown, and also give you an estimate for whatever work is needed.

[petrified.rabbit]

checking a head gasket is sort of easy but can be time consuming. odds are pretty good with the broken thermostat housing that the water pump might now be bad as well. But anyhow..

first things to do is check the fluids, coolant in the oil, oil in the coolant. oil and coolant kind of mix now a days. so its more about which is missing and which is adding.. but neither mixing is a good thing.

next is a compression check, and checking the plugs, they will show if they are burning coolant or oil by the plug "Tips"

[Sweetygirl2312]

Thanks guys for your opinion!
Here is what happened! I didn't want to go back to the first place because this guy had already triedto rip me off, AND I didn't trust his work. That's why I asked the dealership at least 3 times to double check the thermostat!!! They said it was not it, but a head blown gasket issue!
Since I didn't buy it, I took it to another store, and YES, I WAS RIGHT! The thermostat was NOT opening, basically the first place put a used thermostat, and charged me for a brand new!!! Problem fixed for less than $100 while the dealership tried to rip me off by making me change the head gasket!!!
The bad news is that I got ripped off twice but the good news is that I found a trustworthy mechanic!

[avguy]

Thanks guys for your opinion!
Here is what happened! I didn't want to go back to the first place because this guy had already triedto rip me off, AND I didn't trust his work. That's why I asked the dealership at least 3 times to double check the thermostat!!! They said it was not it, but a head blown gasket issue!
Since I didn't buy it, I took it to another store, and YES, I WAS RIGHT! The thermostat was NOT opening, basically the first place put a used thermostat, and charged me for a brand new!!! Problem fixed for less than $100 while the dealership tried to rip me off by making me change the head gasket!!!
The bad news is that I got ripped off twice but the good news is that I found a trustworthy mechanic!

Frankly that's a BIZARRE story from the last shop. We're talking about a $30 part retail. Why would anyone spend the time it takes to get one of these from a boneyard, for let's say $5. That, minus another $2 for a new o-ring, would give a rip-off "profit" of around $23. If someone wants to make an extra $23, the easy thing to do is just pad the labor for that amount.
I highly doubt this story - could be a case of unfriendly competition going on between these 2 shops. And there's an easy way to check it out. Tell them you're going after the first mechanic and want the old part for proof that it was "used". If they say it went into the trash, ask if they will call the first guy in order to support your claim against him of installing a used part and charging for a new one. I think they will try to dance out of their story with some excuse. But if I'm wrong on this, and they are willing to back you up, then by all means go after the first guy!

[Sweetygirl2312]

Well, it may sound bizarre but that's the truth!!! The second shop didn't have any problem to give me back the old part... so I have it !!!! Why did they do that ? Because they made a rip-off profit of $90 for the thermostat, and of $80 for the cooling system flush that they did with water !!!!
I went back there very nice explaining my concerns to the first place but they said I was lying and the other guys didn't do anything!!!! But they gave me back the price that the second shop charged which was 4 times cheaper than this dishonest place!!
How can I go after them??? They are lying!!!!!
BTW the 2 shops are 20 miles away so there is no competition!

Frankly that's a BIZARRE story from the last shop. We're talking about a $30 part retail. Why would anyone spend the time it takes to get one of these from a boneyard, for let's say $5. That, minus another $2 for a new o-ring, would give a rip-off "profit" of around $23. If someone wants to make an extra $23, the easy thing to do is just pad the labor for that amount.
I highly doubt this story - could be a case of unfriendly competition going on between these 2 shops. And there's an easy way to check it out. Tell them you're going after the first mechanic and want the old part for proof that it was "used". If they say it went into the trash, ask if they will call the first guy in order to support your claim against him of installing a used part and charging for a new one. I think they will try to dance out of their story with some excuse. But if I'm wrong on this, and they are willing to back you up, then by all means go after the first guy!

[petrified.rabbit]

the first shop probably replaced the housing and not the thermostat.

[Sweetygirl2312]

Yes, you are probably right!!!!

the first shop probably replaced the housing and not the thermostat.

[avguy]

I've never seen the replacement T-stat housing sold without the thermostat included. Maybe someone does sell it alone, but I've only ever seen it for sale as a package deal. So, it would make absolutely no sense that the first guy installed a new metal T-stat housing, but a used thermostat (even for a rip-off artist).
What part did the second shop give you - just the thermostat, just the T-stat housing, or both of them? The aluminum on a one-month old T-stat housing should still be in good condition - similar to how it came from the box. So it should be easy to determine if that part is one month old, or much older than that. But, if they handed you just the thermostat, and said it had been a used part, I don't even know how anyone could figure that out.
In any case, it's the pits that you or anyone else has to wade through this garbage. I hope your Aveo is now fixed once and for all, and wish you the best of luck with it going forward. And I'll be glad I can continue making my own repairs, and not have to deal with any mess like this.

[Sweetygirl2312]

I don't know what this guy did!!! But it was very clear that the thermostat housing has already been installed on another car (some old sealer was still on it and he hides it with some new red sealer). I can't tell about the thermostat but it didn't open at all.
I agree that this story is a mess but being a woman and going to a mechanic is NOT easy. It's NOT the first time it happens to me! One time, a mechanic charged me $800 and didn't touch my car !
Next time, I will definitely make sure that prices and work are correctly done!
Now my Aveo is working fine, that's the most important !
Thanks for your help!

I've never seen the replacement T-stat housing sold without the thermostat included. Maybe someone does sell it alone, but I've only ever seen it for sale as a package deal. So, it would make absolutely no sense that the first guy installed a new metal T-stat housing, but a used thermostat (even for a rip-off artist).
What part did the second shop give you - just the thermostat, just the T-stat housing, or both of them? The aluminum on a one-month old T-stat housing should still be in good condition - similar to how it came from the box. So it should be easy to determine if that part is one month old, or much older than that. But, if they handed you just the thermostat, and said it had been a used part, I don't even know how anyone could figure that out.
In any case, it's the pits that you or anyone else has to wade through this garbage. I hope your Aveo is now fixed once and for all, and wish you the best of luck with it going forward. And I'll be glad I can continue making my own repairs, and not have to deal with any mess like this.