made my change to lower thermostat sept 2020…running without any problem over a year 20k miles on change, 116k miles now on engine…should of changed sooner..car driving location, long island ny…thanks for info on change

 

Today i put the cooling to the test. Car packed with about 600kg on the rear axle (paper documents) on a windy uphill road. I have mainly drove it like a maniac constantly with 5000-6000 rpm(1st and 2nd gear), it barely reached 88 C. Truth be saying it was only 12 C outside but with the old thermostat i would have been afraid to play with the car as i was seeing 108 C very often on flat roads.

 

This is the second Cruze Ive done this mod on, and IMO neither car ran any different after the change. The coolant temps are what I consider "normal" now. I checked the temp on this second car with my scan tool after a good long drive, and ECT was 183*. Interior heat is reasonable now, not "burn you out of the car" hot like it was before, too.
There might be --- might be --- a very slight drop in fuel economy, but there are so many variables that I cant be sure.
IMO, these lower temps will help coolant parts last longer, so oil system parts will last longer, so engine will last longer, so car will last longer.

 

OK, let’s start!
I had multiple Cruze cars since 2011, unfortunately I can’t say I have/had one free of issues! Talking about the heating and cooling, I saw different & multiple issues reported by people. I did many changes to my cars during the years and I’m going to share with you a few interesting things about the thermostat, specific for 1.4L turbo (ECO). It can be similar issues for other trims, even for Diesel, but the cars I tested & modified are Cruze ECO 2011-2012.
Based on testing 4 cars, here are my observations:
First, the “input data”:

1. The OE Thermostat on Chevy Cruze ECO (1.4L turbo) from 2011 to 2016, is with a wax thermostatic element that starts opening at 105°C (221°F).
2. The OE Thermostat is also wired and controlled by ECM. Based on different algorithms and program codes, the thermostat can open at any temperature at any time, if the ECM requires that!
3. The water temperature display gauge is… a joke! I monitored it for different cars and compared with data from OBD. The dial moves when the temperatures increases until… until 185°F (85°C) only! Then stays there, right before 6 o’clock, no matter how high is the real water temperature. When I tested this, I changed the coolant concentration, adding much more water into the system and let the engine run until the water started boiling. The gauge was at the same position max position, telling me “everything’s ok!

View attachment 254945

4. The expansion OE tank cap is opening only at 20PSI.

Under all these conditions, the coolant temperatures during normal driving conditions stays around 220°-230°F. I said normal driving conditions because when the engine is overheating, the ECM controls and changes everything. It may open the shutter grille to help cooling down and also it can open the thermostat at any temperatures it “wants”, based on data collection. So, not only that you drive with coolant at high temperature, but also the entire system is at high pressure, since the tank cap opens over 20 PSI. In theory, a higher engine operating temperature helps improving its performances. Well, maintaining a higher temperature for the engine and cooling system requires also better quality system parts. Coolant’s boiling point is way too high under the condition I mentioned so everything is ok until… One small crack into the system will lower the PSI and of course the boiling point of your coolant. Add adding more water into the system and you will lower it even more until the coolant will start boiling time to time, without you notice it I replaced the recovery tank a few times, and many hoses all the time! Many others did the same things on this forum.
Sick of changing parts all year along I decided to change the thermostat and go “old school”. It took me a while until I found something that works but here is what I did. I bought a new thermostat housing 55593035Dorman 902-2080 (GM) that is for Cadillac ELR 2014 Chevy Volt 2011-2014. Do not buy MotoRad, it is a different new model, it will not work! You need the one with the “cage”, see the attachment. The housing is different from the outside, but the internal thermostat is fully compatible with Cruze’s thermostat housing. Push the cage and rotate as in my picture, then take out the spring and “cage”. The thermostat will come out relatively easy. It looks the same as the other one, only the wax inside is different and starts opening at 176°F (80°C). Be careful with the 2 legs, don’t bend them so they can go straight back into the housing.
I’ll not got into details of how to take out the existing thermostat, there are good posts on this forum. Put everything back, and make sure you have enough coolant. Then, old school again, I changed the tank cover with one that is opening at 15 PSI, not 20 PSI (MOTORAD T46 )!
I did this replacement on 6 ECO-s and these cars have between 500 to 3200 miles since. No issues at all! The temperature goes usually up to ~184°F then the thermostat is fully opened so the temperature goes down around 180°F. I didn’t notice any drastic changes to MPG! I have hot air blowing inside the car as I had before the swap.
I did all the changes I mentioned because me and my friends have multiple issues with the cooling system since 2011. If you like the solution and have questions, please let me know. I don’t want to argue with anybody about why GM built the system in the way it is so don’t challenge me!

View attachment 254953 View attachment 254961 View attachment 254969

Do you have to use the OEM thermostat housing? I replaced my thermostat about 6 months ago with a Duralast one I believe. Do you know if the swap would work with the Duralast thermostat housing?
I have been fixing coolant leak issues lately and never realized how hot the engine runs normally. After doing some research and seeing a video on youtube talking about this fix, I’d like to try it out.

 

Do you have to use the OEM thermostat housing?

Yes, I used the original OEM housing and replaced only the "guts".

 

Yes, you need to use the car’s thermostat body. The donor one can be from any manufacturer as long it’s opening temp is 80 C

 

Awesome, appreciate the clarification. I will be doing this soon! Volt thermostat on the way and a new 15 psi cap to compliment it

 

You should be alright with the stock 20 psi cap. No reason to go lower.

It's the stat that needs to go. That's a cooker on any engine.

By lowering the temp. You also lower the pressure.

What are you guys doing on the fan side though? That's still programmed to kick on at 230.

 

You should be alright with the stock 20 psi cap. No reason to go lower.

It's the stat that needs to go. That's a cooker on any engine.

By lowering the temp. You also lower the pressure.

What are you guys doing on the fan side though? That's still programmed to kick on at 230.

Start the A/C, or if you want to risk it wire it sperately and put a button for it but i don’t recommend it. For the fan spin it needs a tune and i’m not even sure that you can change it even then.

 

I ask because I'm on the second thermostat ordered and I'd like to know if I'm waiting in vain again

 

The code matches tho and according to the description it should open at 80 C.
Autokarma has the vernet thermostat in their offer at that time they only had the mahle one.

Magazin preferat : - Cautare dupa cod produs - 1338247

www.autokarma.ro

 

Hello! I have an astra j a14net 2014 and I want to put the thermostat of 80 and I ordered behr or something and when it arrived I found that although on the outside it looks the same, the inside was not with the two pins. I returned it and ordered Calorstat Vernet which looks the same on the outside and the code is TE7246.80J and code 55593035 and I hope to find inside what I need to use in my case (the one with the pipe leading to the oil cooler) I now assume that I have on the car the detachable thermostat with the two legs for electrical contact. And one more thing, does the cap have to be changed? if the temperature drops the pressure drops and I say but I saw that if you stay idle the temperature rises and then a 15 psi cap (1.03 bar) would not be too small and give out?

 

The thermostat has come and now it's the right thing to do
I'm curious if the car is the same as the construction so I can put the element of 80 degrees
owns opel astra j from 2014 engine A14 net

 

I have the thermostat. The internal parts look like the pictures posted. I have the cage out, no problem. Does the brass colored piece just pull out ? That's my guess since it has two O rings. Also two terminals that would be destroyed if twisted. I need help !!!!

 

Yes ! the piece is pulled out without twisting possibly spray handsoap for lubrication during assembly

 

Thanks!

 

Happy New Year one and all!

I find this entire thread to be extremely interesting and have read basically every post in it.
I replaced my '12's thermostat last year because the gasket was leaking rather badly and the housing appeared to be weeping through the plastic (as revealed using UV dye in the coolant).
For that reason I did not save the OEM housing and the new one is Brand-X aftermarket (not Dorman) so I have no option to try the core replacement as shown in this thread.
My unmodified thermostat runs at about 222-225F at idle or light loads, and all too often has reached 230-235F under heavier load conditions.
To me this is a completely insane situation that required attention.

Because the thermostat is electrically controlled to an extent by the ECU, it seemed to me that a purely electrical solution should be possible (I am an equipment design engineer).
Long story short, my test solution worked..!
Now it runs at 194-198F at low idle/cruising loads and at about 201-204F on the highway or when climbing hills.
So far, after dozens of warm up cycles and restarts, no DTCs, no issues of any kind, and no apparent hit to gas mileage that I have seen so far (or it is too small to notice).

Not wanting to hijack this mechanical solution thread, I am going to start a new thread showing what I ended up doing in case anyone else wants to try it.

Thanks to the OP for a great thread!!!

 

Place a link to that thread here and consider linking this thread in yours.

 

Done. 😁
A link to this thread is located at the top of my thread and here is a link to mine-

Electronic control of thermostat temperature 1.4T

Happy New Year! This is a variation on the original mechanical solution thread which is found at- https://www.cruzetalk.com/threads/1-4-eco-thermostat-swap-221%C2%B0f-to-176%C2%B0f.225041/ Thanks very much to the OP for a great thread!!! --------------------------------- NEW- There is now a...

www.cruzetalk.com

 

Do you think that if we adjust the new 80 degree thermostat by 2mm, it will open later ... around 90😀?

 

It would make little or no difference to the opening temperature of an 80 degree thermostat because the thermostat is driven by a wax motor element.
Shortening the rod will not change the temperature at which the wax melts and expands so it will not change when the pin begins to move.
The only thing this will definitely do would be to reduce the maximum opening distance of the regulating valve, so personally I wouldn't do it.


By the way, the electronic control I added to mine, which is now using a voltage regulator set to 10.0 volts, is working perfectly.
It regulates the engine temperaure at 198-203F under pretty much any driving conditions.
So far no DTCs, no delays to warmup, no noticeable hit to gas mileage, nothing at all bad.
Oh, and the (mostly) useless dashboard temperature gauge is running very slightly to the left of the tick mark to the left of bottom center, very close to where it was indicating at 220-225F.
A waste of a gauge...

 

adjustment, ie to shorten the rod so that any errors or going too cold do not occur
what do you say

 

Yes, I thought that just as the Russians added the 2.5mm pill to the original thermostat to open earlier, so I wanted to shorten the rod to open later.
All in all, I don't know how reliable the thermostat heater is to be supplied all the time


Da ,,,, ma gandeam ca asa cum rușii au adaugat pastila de 2,5 mm la termostatul original pentru a deschide mai devreme ,asa si eu vroiam sa scurtez tija pentru a deschide mai tarziu.
Una peste alta nu stiu cat de fiabil este sa fie alimentat tot timpul rezistenta termostatului

 

Ok

 

So I originally posted the GM OEM One and the next part I found is this one on eBay I'm pretty sure it's not the right part so can anybody let me know before I order it thx

22MQ15H Engine Coolant Thermostat Housing Assembly Fits 2011-2015 Chevy Volt | eBay

Find many great new & used options and get the best deals for 22MQ15H Engine Coolant Thermostat Housing Assembly Fits 2011-2015 Chevy Volt at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

Was doing a test drive today on the Cruze for another reason, and looking at the live data, the lower temp Tstat is running right around 183-186* once warmed up. I had no problems with that temp, as that is what "normal" operating temps used to be.

 

Am modificat termostatul (103 la 80) si capacul vasului de expansiune (20 psi la 17 psi) nu a aparut nicio eroare si motorul merge la ralanti cu aerul functionand la o temperatura exterioara de 25 grade Celsius la max 84 In mers, cu sau fara aer, intre 79 si 85 de grade Celsius Motorul se simte bine si nu mai face presiune pe furtunuri...eee Ok! 👍 Merită toată bătaia de cap, rezultatul este uimitor pentru durata de viață a motorului Turbina prosperă, motorul nu mai scoate sunete ciudate de răcire după oprire. Felicitări tuturor celor care își dau interesul și postează soluții!

I modified the thermostat (103 to 80) and the expansion vessel lid (20 psi to 17psi) no error occurred and the engine is idling with the air running at an outside temperature of 25 degrees Celsius at max 84 On the go, with or without air, between 79 and 85 degrees Celsius The engine feels good and no longer creates any pressure on the hoses ... eee Ok! 👍 Worth all the hassle, the result is amazing for the life of the engine The turbine is thriving, the engine no longer makes strange cooling sounds after stopping Congratulations to all those who give their interest and post solutions!

 

With regard to Chevy Cruze's coolant temperature, 190 to 225 degrees F is considered reasonable. Heat is generated by a liquid coolant that has a temperature above 240 degrees Fahrenheit.

Heat is generated by the engine using a coolant mix with a boiling point of 223*. Fan kickon was 231*

The hotter things run. The more likely things are to fail.

190* has always been the norm. Although back in the day temps as cold as 160 and 175 could be bought. It was pretty common to bore out motors. Thinner cylinder walls made higher Heat and required a colder thermostat and an extra core radiator.

 

On the topic of the useless gauge... basically all cars are like that. They are calibrated such that when there is no problem, it just parks. There is usually a 4 to 8 point calibration curve that is linear up until some point then very non linear near the overheat end. Usually the last handful of degrees C. Right before AC cutout, a d up to overheating messages. As opposed to constantly dithering back and forth with the fan command, driving, ect... Studies have shown that the dithering is a customer dissatisfier. Keep in mind, that cars are not catered to the few car enthusiasts, but to the masses. On the whole, as long as there is not a problem this would be fine. I certainly agree the gas Cruze runs hot by design, which in my opinion was a mistake.

My 4th gen Camaro gauge parks just to the left of 12 o'clock, which would indicate about 200F. But I know for a fact that it goes up to 226F when sitting in traffic before the fan comes on to bring it back down. The gauge doesn't move, even though there is an indicator for 235 halfway between 210 and 260.

I've also seen that 1996 and older Saturn's gauges will go to "almost overheating" on the gauge, when it's only 226F, fan comes on, cools it to 204F and the gauge comes back down. They made the change because people thought there was a problem, when in fact there was not.

All that to say, don't trust the gauges for absolute temperature. They exist to tell you when there is a problem. Most often times that is enough.

Sent from my SM-G781V using Tapatalk

 

"I've also seen that 1996 and older Saturn's gauges will go to "almost overheating" on the gauge, when it's only 226F, fan comes on, cools it to 204F and the gauge comes back down."

I used to have a '97 Saturn SC2 and it did exactly that.
I added a secondary independent control that sensed the temperature of the radiator and turned the fan on to keep it no hotter than about 180F.
Then the regular thermostat could do its job consistently.
The temperature gauge became rock steady and my scan gauge confirmed that the engine temperature really was steady.

FWIW...

 

I'd want to know what the head is doing. Nit the radiator.

The head is the hottest point.

 

I'd want to know what the head is doing. Nit the radiator.

The head is the hottest point.

Yes that is the ultimate goal.
However, the radiator must necessarily be a source of lower temperature coolant than the thermostat's setpoint to allow it to do its job correctly, and in turn for the head to be cooled.
This is just the way any cooling system and thermostat setup works.
On cars with active grille shutters for example, even if you change the thermostat to a 180F type, the engine computer will choke off airflow to the radiator until the engine reaches its "desired" factory temperature of around 225F.
So changing the thermostat in that situation will do almost nothing under highway or summer heat loads.
I know this for certain because that is exactly how it worked on my own Cruze (which has active shutters) and on the Saturn too.
I had to defeat the shutters on my car so that they would stay wide open and then the thermostat was able to function properly.
Otherwise the temperature would just rise up to the original 225F-235F before the grilles would open and the radiator fan turned on, making the change in thermostat setpoint irrelevant.
The radiator fan needs to turn on at a lower temperature than the engine computer tells it to from the factory and lower than whatever temperature the thermostat is set to.

 

If you made it this far in the thread. Then you are pretty desperate for a magic trick to bring the coolant temp down. I have 3 cruzes and picked up a 4th one on the date off this post. 3 Gen 1's 2008 to 2012. And one Gen 2 2013 to 2016.5. All 4 were bought with dead motors. The mileage is between 74,000 and 131,000 miles. Here's what all 4 have in common. The previous owners took very poor care of the cars. So when mechanical issues related directly to running and driving. It was too late and too expensive to save the car. My advice: learn to take great care of the car that takes great care of you. Then the issues won't exist and the car will be just as reliable as the day you bought it new.