Chevrolet Cruze Forums banner
Cancel

1.4 ECO - Thermostat Swap - 221°F to 176°F!

141045 Views 269 Replies 58 Participants Last post by  Tag, 
CRUISE-CRUZE
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 2011-2014.
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!
Text Font Auto part Speedometer


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! :p

Auto part Font Automotive lighting Automotive super charger part Automotive fog light
Water Fluid Drink
Water Plastic Plastic bottle Cylinder
See less See more
4
Reply
Save
Like
  • Like
  • Love
Reactions: 5
221 - 240 of 270 Posts
NUMBER2
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
See less See more
Reply
Save
Like
D
"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...
Reply
Save
Like
  • Like
Reactions: 1
S
I'd want to know what the head is doing. Nit the radiator.

The head is the hottest point.
Reply
Save
Like
D
snowwy66 said:
I'd want to know what the head is doing. Nit the radiator.

The head is the hottest point.
Click to expand...
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.
See less See more
Reply
Save
Like
Cruzetruth
DIYguy said:
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.
Click to expand...
That's what I was thinking reading the ops post. The shutters will close bring the temperature up to the factory settings. So lowering the Thermostat to 176 is defeated.
Reply
Save
Like
Cruzetruth
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.
Reply
Save
Like
D
Cruzetruth said:
That's what I was thinking reading the ops post. The shutters will close bring the temperature up to the factory settings. So lowering the Thermostat to 176 is defeated.
Click to expand...
Unfortunately... yes.
However, it is relatively easy to defeat the shutters.
There are multiple writeups about that, including two different methods I have personally tried and verified to work.
One of them in particular is dirt simple (changing out the fuel pump module) and will take all of 15 minutes to do on a bad day.
However, there is one final "gotcha" lurking in the weeds as I had mentioned, which is the radiator fan turn on temperature.
Fortunately there are many ways to overcome that including independent thermostatic controls that can be wired across the existing fan relay and set to turn on at lower temperatures.

I just saw your second posting and totally agree with you.
"Take care of the car that takes care of you."
Letting it run at 225F-235F is just flat insane as far as I am concerned, and is only asking for trouble.
FWIW... :)

Oh, and nothing I have described qualifies as magic. :sneaky:
None of it is particularly difficult or expensive to do either if taken step by step.
See less See more
Reply
Save
Like
CRUISE-CRUZE
Cruzetruth said:
That's what I was thinking reading the ops post. The shutters will close bring the temperature up to the factory settings. So lowering the Thermostat to 176 is defeated.
Click to expand...
You're wrong! :)
The shutter is not only controlled by temperature changes but other algorithms. Even if that would be the case, still no issues, the updated thermostat will always open at lower temperatures since it is built in that way mechanically, it doesn't need to computer to tell when to open! Last, if you still have concerns, just change the fuel pump module from one without the shutter and you will resolve the "problem". I did so many of these swaps until now and never had an issue with the shutter, believe me, it does work even after the thermostat changed! I had a mercury switch on it with an LED inside the cab and I could monitor the shutter functionality all the time. ;)
Reply
Save
Like
D
CRUISE-CRUZE said:
You're wrong! :)
The shutter is not only controlled by temperature changes but other algorithms. Even if that would be the case, still no issues, the updated thermostat will always open at lower temperatures since it is built in that way mechanically, it doesn't need to computer to tell when to open! Last, if you still have concerns, just change the fuel pump module from one without the shutter and you will resolve the "problem". I did so many of these swaps until now and never had an issue with the shutter, believe me, it does work even after the thermostat changed! I had a mercury switch on it with an LED inside the cab and I could monitor the shutter functionality all the time. ;)
Click to expand...
Yes, changing the fuel pump module to a non-shutter version, or doing a mechanical defeat of the shutter motor (I wrote both methods up as "how-to's") will fix any shutter problems regardless of whether you change the thermostat to a lower temperature one (great idea, by the way) or electrically cheat it as I have done.
But unless you defeat the shutter it will continue to open and close.
This behavior is described in the factory service manuals.

I was monitoring the engine temperature essentially all the time while driving for the first three or four months after making my original modification.
I found much to my great disappointment that it climbed right back up to 225F or so while driving for long distances at highway speeds on hot days even though it worked perfectly around town or on short trips.
This is because the shutters will close, choking off airflow through the radiator and causing its outlet temperature to rise regardless of the thermostat setpoint.
The temperature then climbs until the engine computer finally decides that it needs to open the shutters again and perhaps even turn on the radiator fan, at around 225F-235F sadly.
This "feature" of operation is also described in some detail in the factory service manual.

Once I realized what the problem was and defeated the shutters completely there hasn't been a single repeat of the problem at highway speeds.

However, at extended idle in very heavy miles-long commuter stop and go traffic with high outside temperatures, the radiator once again cannot output coolant at a low enough temperature to cool the engine down even with the shutters forced wide open.
Insufficient airflow...

This is why a method of turning on the radiator fan sooner such as a secondary fan controller is needed.
You can very easily prove this by simply turning on the A/C, which is how I trouble-shot the problem in fact.
It is supposed to turn the radiator fan on at low speeds, so the temperature will drop right back down again.
This can also easily be accomplished by a "tune" to lower the radiator fan turn on temperature, but around here such a tune can theoretically fail the car during emissions testing ("tampering"), so it is to be avoided.
Or by cheating the sensor located in the passenger side end tank of the radiator so that the computer thinks the coolant outlet is warmer than it really is (I have an idea for a cheap and simple fix for that actually that I will be trying out soon as summer approaches).

I had a very similar radiator overtemp problem with an old Saturn, though it did not have shutters of course.
It forced me to install a secondary radiator fan controller which was set to about 180F (as sensed at the radiator outlet).
Problem solved once and for all and the engine temperature was rock steady from that point onward.
It was always right at the thermostat's temperature as it should be.
I sold that car to a friend several years ago.
The controller went with the car and the setup is still working perfectly after many thousands of miles of operation.

FWIW...:)
See less See more
Reply
Save
Like
S
How does one buy 3 gen'1s 2008 - 2012 and one gen2 2013 - 2016?

Gen1 went from 11 - 16 and gen 2 went from 16 - 19.
Reply
Save
Like
  • Like
Reactions: 1
CRUISE-CRUZE
DIYguy said:
But unless you defeat the shutter it will continue to open and close.
This behavior is described in the factory service manuals.
Click to expand...
I've studied a lot the shutter's behavior in the beginning, I think I have an older post somewhere here on this forum. Let's forget a second about it. The thermostat's wax elements transform heat energy into mechanical energy using the thermal expansion of waxes when they melt, and for the thermostat I picked that happens around 176°F. The computer has nothing to do at all in this case so you will drive safely all the time!
Back to the shutter now, in the winter it does not work at all, it is a low temperature limit that is a safety factor also and the computer won't let the shutter engage below that. I'll try to find my old post somewhere about this study. Now, for the warm weather, even the computer will keep the shutter closed, you should have no issues, you are always (mechanically controlled) under 176°F with the new thermostat!
Let me know if I could explain better this time? :)
See less See more
Reply
Save
Like
Chickenbreast
Hi all,

I registered in this forum especially for this thermostat topic.
I do not drive a Chevrolet, but an Opel Adam S with B14NEH engine, which has the same "heat problems".
The normal water temperature is about 102°C - 104°C (215°F- 220°F) during normal driving.

But the way, my car hasn´t any shutter - therefore it shouldn´t be a problem.
Which is definitely not possible if you only change the thermostat temperature in the map.
Therefore I think, also with the posting of DYI-Guy, that there is a dependence to the fan control.

Likewise, the engine load is a dependency or can affect the thermostat.
For example, at speeds above 160km/h (100mph) as well as enough engine load, the thermostat opens and the water cools down to about 85°C (185°F) for a short time.

I am in contact with some tuners, who tried to adjust the temperature map, but this did not give any result yet.
The dependence, for example on the fan, was always disregarded.

I will later after work again flash two files to the ECU and report.
Has anyone been able to gain experience with modifying the ECU data or the map for the e-thermostat?
See less See more
Reply
Save
Like
Chickenbreast
So far so bad - the first files doesn't work, because the fan wasn't turned on.
The second ecu file is just crap - there is an issue before the writing on the ecu begins.

Therefore I need to wait for a corrected version.

A/C turned on makes just a difference of 2-4°C.

In my case (stock ECU fan mapping) - thermostat opens mechanically at 105°C.
At 107°C the fan runs as 100%.
At around 102°C it is 'just' 80%
At 91% around 30%..
See less See more
Reply
Save
Like
Cruzetruth
Chickenbreast said:
Hi all,

I registered in this forum especially for this thermostat topic.
I do not drive a Chevrolet, but an Opel Adam S with B14NEH engine, which has the same "heat problems".
The normal water temperature is about 102°C - 104°C (215°F- 220°F) during normal driving.

But the way, my car hasn´t any shutter - therefore it shouldn´t be a problem.
Which is definitely not possible if you only change the thermostat temperature in the map.
Therefore I think, also with the posting of DYI-Guy, that there is a dependence to the fan control.

Likewise, the engine load is a dependency or can affect the thermostat.
For example, at speeds above 160km/h (100mph) as well as enough engine load, the thermostat opens and the water cools down to about 85°C (185°F) for a short time.

I am in contact with some tuners, who tried to adjust the temperature map, but this did not give any result yet.
The dependence, for example on the fan, was always disregarded.

I will later after work again flash two files to the ECU and report.
Has anyone been able to gain experience with modifying the ECU data or the map for the e-thermostat?
Click to expand...
Pick one. I tried both over the weekend. Here's the results. The 15 psi cap and the 217 degree thermostat with antifreeze. on a 20 mile drive. After first no change in 10 miles. Same temp. On the way back. The temperature fell to 179 degrees and temperature started jumping around. Next test. 15 psi cap and the 176 degree thermostat running water on the same 20 mile drive. The temperature stayed between 154 to 162 degrees. A code in the ecm for bank 1 too lean with rough idol lifter tick.. Next test. 20 psi cap and the 176 degree thermostat with water as coolant on a 10 mile drive. The temperature stayed between 194 and 201 degrees no engine codes, no ticking, no rough idol. At no time did the shutters try to close during the test. So I found the right combination that works on my car. The 20 psi cap and the 176 degree thermostat. I live in Florida. It was 98 degrees and 100% humidity during the tests. I hope this information helps. When they get here. I'm going to try the hayden adjustable cooling fan kit. If you have noticed. I don't give misleading information. Advice for the Thermostat swap. There's 2 housing for the 1.4 ecotect. One for the oil cooler return line. And one without. The water pumps are the.same between both engine setup. While I was at the parts store. I asked to look at the non Turbo water pump. To the point. If you have to swap out the Thermostat Stat guts. Make a mark on top of the brass thermostat sensor in line with the harness plug in the plastic housing. This keep you from putting it in up side down. Don't twist the brass sensor. Pull it straight out as possible.
See less See more
Reply
Save
Like
D
CRUISE-CRUZE said:
Now, for the warm weather, even the computer will keep the shutter closed, you should have no issues, you are always (mechanically controlled) under 176°F with the new thermostat!
Let me know if I could explain better this time? :)
Click to expand...
No, sorry but let me explain it a bit better this time.
It doesn't work the way you said above in my own experiences with my own Cruze and on other similar vehicles.
Nor would any automotive engine design engineer agree with your statement.

The coolant exiting the radiator must by default be lower in temperature than the thermostat's setpoint for the thermostat to be able to regulate the engine's temperature.
This is because the thermostat works by metering lower temperature liquid into the engine to draw away the engine's heat.
This process operates per the rules of basic physics and engineering and is a fact, not an opinion.
Hot coolant simply cannot cool the engine down to a temperature lower than itself no matter what the thermostat's setpoint is.

So if you choke off the radiator on a hot day in a manner that the radiator heats up past the thermostat's setpoint, the engine temperature will rise up above the thermostat's setpoint until the shutters finally open and/or the radiator fan turns on to cool the radiator down again.
Been there, done that, seen it happen with my own eyes on my own Cruze.

Not to further press the point, but it doesn't matter in the slightest whether you agree with any of this or not.
It simply "is" whether you personally believe it or not.
But I do hope others will read this and understand a little bit of how basic high school physics works.
All I am going to say...
See less See more
Reply
Save
Like
CRUISE-CRUZE
You are with the theory, I'm with the practice looks like! IF you change the thermostat in the way I described it will work without any issue, I did it for many cars without any issues in the summer. You forgot 2 things in your theory, the thermostat opens way lower so to overheat the motor you would have a very hot day and get the engine very hot under a lot of loads but.. in that case the fan will start and cool down the water in the radiator very fast. Another detail is that the shutters are covering just a portion of the radiator, the top part will always have a rectangular window always open, enough to have no cooling issues! Other details if you want: with the original fuel pump module the shutters still open when overheat, changing the fuel pump module will keep the shutters always opened.
Give it a try with the thermostat I recommended and see how it works. There are other guys on the forum who did the swap and had no issues. Again, the theory is good, but the practice is different, like in life!
See less See more
Reply
Save
Like
D
CRUISE-CRUZE said:
You are with the theory, I'm with the practice looks like!
Click to expand...
Actually no... I forgot nothing.
I am speaking from actual practice and hard experience (50+ years working on vehicles of all kinds), and from consideration of all the potential operating conditions, some of which you may not (yet) have encountered.
You just got lucky (so far).
Or else no one is looking at the right measurement at the right times.
Or perhaps they don't understand what they are seeing.

By actual measurement (not theory) the shutters block off around 70% of the radiator's air inlet area when closed.
This is hardly a minor thing on a hot day when climbing a long incline at 70 mph.
Try climbing up the Grapevine north of L.A. on a hot day with your mod alone and closed off shutters and see what happens.
The radiator cannot sufficiently cool the coolant if there isn't enough airflow passing through it (or none at all in stalled traffic).
Impossible.

The engine computer will not turn on the radiator fan or open the shutters until the temperature as sensed on the passenger side radiator tank (the radiator's exit side) or the engine block temperature sensor get to considerably above 200F (like 225F in fact).
This is by actual measurement and is not a theory, GM did this very same (stupid, IMHO) thing on other vehicles too.

Heat always flows from hot to cold.
Do not believe me, see for yourself- https://en.wikipedia.org/wiki/Second_law_of_thermodynamics
So if the coolant from the radiator rises above 200F in certain conditions as a result of insufficient airflow, the thermostat literally might as well not even be present for all the good it will do when you are trying to reduce the engine's temperature below 200F.
The hot coolant leaving the radiator cannot cool the engine any lower than its own exit temperature.
Fact.

So again, either you got lucky so far, or you just haven't encountered the worst case situations (as I have repeatedly).

You cannot force someone to understand or accept a reality they have not experienced, so this is "it" for my attempts to do so.
However, please understand that I am not and never was, criticizing the concept of the original posting in this thread.

But please do not tell me that I did not personally experience what I have experienced (it is fact, not theory).
I have the knowledge and ability to determine the root cause of why it happened and to correct it.
And so I did.

Have a nice day...:)
See less See more
Reply
Save
Like
  • Like
Reactions: 1
CRUISE-CRUZE
Whenever are ypou
DIYguy said:
You just got lucky (so far).
Click to expand...
A LOT of luck then since I've modified myself around 20 cars since 2018 with this particular swap and no issues reported back from any of these! I can play lottery then!
Open invitation: if you are in Detroit area at any time this year and have a half day open, just PM me and I'll get in touch with you, show you the changes I've done on my actual 3 Cruze cars and we can also do any kind of tests and monitor any parameters, I have the tools.. and, why not, we can go after that for a lunch and a beer too, if I'm right you pay it, if not you're my guest! :)
Reply
Save
Like
Cruzetruth
Cruzetruth said:
Pick one. I tried both over the weekend. Here's the results. The 15 psi cap and the 217 degree thermostat with antifreeze. on a 20 mile drive. After first no change in 10 miles. Same temp. On the way back. The temperature fell to 179 degrees and temperature started jumping around. Next test. 15 psi cap and the 176 degree thermostat running water on the same 20 mile drive. The temperature stayed between 154 to 162 degrees. A code in the ecm for bank 1 too lean with rough idol lifter tick.. Next test. 20 psi cap and the 176 degree thermostat with water as coolant on a 10 mile drive. The temperature stayed between 194 and 201 degrees no engine codes, no ticking, no rough idol. At no time did the shutters try to close during the test. So I found the right combination that works on my car. The 20 psi cap and the 176 degree thermostat. I live in Florida. It was 98 degrees and 100% humidity during the tests. I hope this information helps. When they get here. I'm going to try the hayden adjustable cooling fan kit. If you have noticed. I don't give misleading information. Advice for the Thermostat swap. There's 2 housing for the 1.4 ecotect. One for the oil cooler return line. And one without. The water pumps are the.same between both engine setup. While I was at the parts store. I asked to look at the non Turbo water pump. To the point. If you have to swap out the Thermostat Stat guts. Make a mark on top of the brass thermostat sensor in line with the harness plug in the plastic housing. This keep you from putting it in up side down. Don't twist the brass sensor. Pull it straight out as possible.
Click to expand...
The final results: I went back to the factory 217 degree thermostat and 20 psi Radiator cap. Following issues occurred today. Rough first start, pulsating idol after warm up, bank 1 too lean code came back, 50% loss in fuel mileage, explain this please.. it's 17.9 miles to work. The car used 1/2 of gas before the coolant swap.. after the swap.. it used one gallon of gas to drive the same distance. the ticking lifters got worse, air conditioner did not start cooling until the coolant reached 205 degrees. Hesitating from during take off. Performance went in the toilet. So in conclusion of cruze-cruze cooling system fix. It works as far as keeping the engine cool. It fails over a number of issues found during the trial test of the Thermostat and Radiator cap swap. I'm not saying don't do the swap. Just making everyone aware of the consequences doing the swap.
See less See more
Reply
Save
Like
D
CRUISE-CRUZE said:
Whenever are ypou

A LOT of luck then since I've modified myself around 20 cars since 2018 with this particular swap and no issues reported back from any of these! I can play lottery then!
Open invitation: if you are in Detroit area at any time this year and have a half day open, just PM me and I'll get in touch with you, show you the changes I've done on my actual 3 Cruze cars and we can also do any kind of tests and monitor any parameters, I have the tools.. and, why not, we can go after that for a lunch and a beer too, if I'm right you pay it, if not you're my guest! :)
Click to expand...
Thanks, no hard feelings at all.
As I live about 2100 miles from you and haven't been to Detroit since the early 1980's when I was considering a job as an engine controls engineer at one of the big four (at that time :confused:) auto makers, it is unlikely.
I decided against relocating there obviously, and chose a rather different engineering career instead.
Believe me though, I do know how engine controls are designed and how they work...

BTW, one of the conditions I specifically encountered was a sustained run over the course of about half an hour and about 30 miles distance.
The vehicle speed was always above 60mph, the OAT was around 90F, and the A/C was off (so no fan).
These are all conditions that the ECU uses to determine the "need" for a shutter closure.
Despite running in the high 190's F prior to that, it suddenly began climbing up to 225F-230F as it did before my electronic thermostat mod.
Then on the return trip it did the same thing again after about 30 miles of highway driving.
If you do not duplicate those conditions you will probably never encounter the problem at all, to be quite honest.

Since defeating the shutters, there has not been even one repeat of this behavior and it happily runs now at around 196F-205F under basically identical conditions.

The problem with 176F as a mod is that we have draconian emissions testing here and it could fail for various reasons if operated at that temperature.
If there had been a 195F option using your method (believe me, I searched for one) I definitely would have tried it.
So it was just not an option for me.
Again, no disrespect for your method or original posts.

I am currently working on an elegant cheat of the fan controls to regulate the radiator output to a lower temperature.
I did this on another car and it worked like a charm but it may or may not work as well on the Cruze.
However, if that doesn't pan out I will just use a commercial secondary fan control thermostat.
In fact I already have one stuck away in a cabinet somewhere... if I can remember where I put it... :rolleyes: o_O
See less See more
Reply
Save
Like
221 - 240 of 270 Posts
Chevrolet Cruze Forums
CruzeTalk.com forum, news, discussions and the best community for owners to discuss all things related to the Chevy Cruze.
Full Forum Listing
Explore Our Forums
General Discussion Gen1 1.4L Turbo Gen1 Service Issues 👋 CruzeTalk New Member Introductions Gen1 Appearance, Body, Detailing, & Interior
Top