# Engine thermostat replacement



## Gzuz4132 (Jul 13, 2021)

Call the dealership that did the work previously. They may at least check at no charge.

This is also a common coolant temp sensor issue though and if it is, they'll charge you since it's not the same problem in this scenario


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## evilfix (Jan 13, 2017)

Gzuz4132 said:


> Call the dealership that did the work previously. They may at least check at no charge.
> 
> This is also a common coolant temp sensor issue though and if it is, they'll charge you since it's not the same problem in this scenario


Thanks for the info, I will do that.

When I got home from work today there was a bit of white smoke and in the attached image i circled where a hose had a constant drip. For a few minutes during the drive there was even white smoke being blown into the car out of the air vents. That only lasted for a few minutes though.


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## Johnny B (Jun 4, 2019)

Having that coolant leak is probably the issue. If the coolant isn't being pressurized as it warms up, it will never get above about 212F. And the computer is probably looking for the coolant temperature to reach about 220F (just a SWAG) at some point, and when it doesn't it throws the P0128 code. The thermostat is most likely working fine.

Having a long term leaking coolant system on your car is a great way to kill it, keep the overflow tank filled and fix the leak ASAP.

Also, your valve cover is leaking like a sieve, not replacing it WILL cause engine issues.


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## CRUISE-CRUZE (Nov 8, 2010)

If you wan to try, do "my fix"  and you'll never have issues with the thermostat. I did or help others to do this swap for around 30 cars. The issue seems to be that the thermostat I used as replacement is hard to find:

1.4 ECO - Thermostat Swap - 221°F to 176°F! | Chevrolet Cruze Forums (cruzetalk.com)


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## evilfix (Jan 13, 2017)

Johnny B said:


> Having that coolant leak is probably the issue. If the coolant isn't being pressurized as it warms up, it will never get above about 212F. And the computer is probably looking for the coolant temperature to reach about 220F (just a SWAG) at some point, and when it doesn't it throws the P0128 code. The thermostat is most likely working fine.
> 
> Having a long term leaking coolant system on your car is a great way to kill it, keep the overflow tank filled and fix the leak ASAP.
> 
> Also, your valve cover is leaking like a sieve, not replacing it WILL cause engine issues.


Great info. Thanks!


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