[Stingray1974]

I had a 2012 Cruze ECO and now a 2015 ECO. This is a great car and with 42 mpg is very efficient. I had the coolant problem with both cars and have worked with dealers and GM about 3 years and still have the problem. Many customers having the same issues that cannot be resolved in 2011 through 2015 model years.

The sealed coolant system can only lose coolant two ways. 1. By a leak and none have ever been found on my cars and 2. By high temperature allowing gasses to escape out the overflow which appears to be happening. The bulletins and recalls mostly deal with the odor symptom like routing the overflow to the ground and not the root cause of overheating. Obviously they know the tank is venting coolant and by overheating.

It's difficult for customers to know the car is getting a little hot. In fact you have to monitor the OBD11 data to see it overheats because the gauge only goes up to about midway at 190 deg F and even if temperature goes over 240 deg F the gauge does not move further. I have noticed high temperature above 240 deg F in some circumstances that allows boiling, odor and coolant loss. This can happen in the winter and summer both and loss is 4-8 ounces at every oil change.

I looked at the cooling program and it shows a 194 deg mode and a 221 deg mode. The 221 deg mode algorithm does not respond until temperature gets hot in a couple torque modes. The 221 mode is different from the 194 mode and other cars I have looked at. I proposed a program change to prevent this overheat condition and the cause of the odor and fluid loss. Unfortunately I am still waiting on GM to fix the problem, they said if I make the change it will void my warranty.

Please let me know if you have coolant loss/odor and what your thoughts are. I have worked with Dealer, Manager, District Manager, GM Customer Care, Corporate Office and others and still trying to get this fixed and to help them identify the root cause so they can fix this problem for other customers.

This is ECT Program



Here is proposed Program

 

[Eddy Cruze]

I was pretty sure this issue was addressed by the time I purchased my 2014 1LT? I live in the hottest area of the United States and have experienced little to no coolant loss?

 

[Tomko]

Paragraphs.

Give your words.

More substance.

 

[jsusanka]

Tell them to replace the water pump, water outlet, and coolant tank cap. If those things are installed properly your problems will go away. Just make sure they bleed all the air out of the system after replacing those parts. Ever since my water outlet got replaced my odors are gone. I don't think they are installed properly to the head and are either sucking air in or leaking so little not even a pressure test will show it and are allowing air in the system and screwing it up.

 

[obermd]

The other big source of coolant loss is the lower o-ring on the cap on the coolant reservoir. When it's cold this o-ring doesn't hold pressure. Once the cap warms up the o-ring will hold pressure. This will result in up to half a rib of coolant loss between oil changes in the winter. During warm months this isn't an issue.

 

[Stingray1974]

Do you have the 1.4 turbo engine? This seems to be the one with trouble because the Turbo gets hotter. Actually I do not have much coolant loss or problem when it is hot out, the system seems to do better then.

 

[Stingray1974]

You might be right water pump and other items may have something to do with it. In my 2012 they replaced the tank twice, replaced Electronic Thermostat, replaced water pump and the heater core and problem only got worse. Maybe slight differences in cooling system let some get hot and vent where others are right on the edge and do not. There are LOTS of customers with this problem and several bulletins and recalls from GM so they must not have good fix yet.

 

[Stingray1974]

Good point. If the pressure gets higher due to high temperature and gas this would cause the o-ring to leak more.

 

[carbon02]

There's many threads on this website about the radiator coolant bottle cap o-ring venting. There's over a half a dozen of us that have fixed a similar issue by installing new o-rings on the radiator cap.

You can try to get Chevrolet to shake this down for you, or you can try a $1.19 fix. I'm going through o-rings at the rate of 1 per year, but I'm ok with that rather than running to a dealer to throw parts at it.

Make sure there's no air in the system. The systems are meant to bleed liquid back to the coolant reservior off the water outlet on the drivers side of the engine. Unless you have a huge air pocket, say a heater core replacement, you are probably ok.

The coolant system is running a 20 psi cap pressure, with high isolated water temperatures, the O-ring simply deforms due to heat. The compression set in the ring is too much, and it leaks.

"Google" Cruze Radiator Tank O-ring replacement, you will find the theads..

 

[joeroot9357]

can i see some photographs of it here? a help would be appreciated

 

[NickD]

It's difficult for customers to know the car is getting a little hot. In fact you have to monitor the OBD11 data to see it overheats because the gauge only goes up to about midway at 190 deg F and even if temperature goes over 240 deg F the gauge does not move further.

Using OBD II data to determine the fault in a vehicle is tantamount to using a lie detector on a natural born liar. With temperature problems you need external verified accurate temperature measuring equipment to find the true problem. A self diagnostic system can only rely on its own sensors that can be lying like crazy to provide completely false data.

Automotive diagnostic systems are the bottom of the barrel, no secondary references are incorporated. No wonder why your problem is dragging on for years, working with idiots.

Difference between the Cruze and vehicles made for the last 30 some odd years, is the increased coolant operating pressure. Typical pressures were in the 15 psi range, Cruze is operating at 25 psi. So to test these system, still require a pressure tester, but have to test in the 40 psi range.

Had a radiator cap pressure tester for years, ever see a Cruze recovery tank cap tester? It is possible to detect leakage as low as a half a cup per month, if you only had a tech that knew what they were doing.

Every sensor used in these vehicles has a set of specifications and acceptable tolerances, the only problem is that GM does not provide them to their mechanics, so they are working in the blind and just guessing.

Don't like to hear toxic odors, fact is, these toxic odors are kidney killers, and we were only given two of these, and both are susceptible to severe damage by these odors. Wouldn't even drive a vehicle with toxic odors, you life is at stake.

Should have given this some consideration by using very unreliable O-Rings, and by getting rid of the radiator cap, that super high recovery tank pressure is only increasing the possibility of creating more problems that never existed before.

Been watching my fluid levels like a hawk.

 

[Stingray1974]

Update.... COOLANT LOSS FIXED!! I made the ECT program change and have not lost any coolant for the first time since new. The temperature does not get above 228 deg except for once after turned off temperature went up to 332 deg.

 

[winks79]

Have the same problem with my daughters since new. It's a 2013, shows no leaks anywhere, I just add a little coolant every 10k miles or so. Have about 62k miles on it, and has never gotten worse or better. Just something I've learned to live with. This is the only issue the car has ever had.

 

[Blue Angel]

Copied from my reply in the O Ring thread:

1. Did you notice any change in how the car runs, particularly under boost in high ambient temps?
2. Did your check the ignition maps to see if there are any temperature related changes as a result of slightly lowering the coolant temperature?

The reason I ask is, I've noticed my car runs very well right up until about the point where the engine temp maxes out (a minute or two after the gauge gets into its happy place). After that, when it's warm out, I notice some slight inconsistency in power delivery, and only from time to time. The feeling is that the ignition advance is fluctuating, and I know there's lots of talk about "phantom knock" where the engine just seems to pull timing on a regular basis under load. Just wondering if dropping the peak coolant temps slightly has any effect on this?

If there's coolant boiling somewhere, particularly in the head, this could be a source of knock.

I also noticed there are two positions for the relief spring in the coolant cap, the lighter of the two being where it's set on our cars. I wonder if stepping up to the higher spring load in the cap would keep the coolant from boiling (if that's the issue)? I hesitate to simply try it out since I'm not sure what the higher setting is on the cap. Stock is 20 psi, if the higher setting is only 22-25 psi or thereabouts it's probably OK, but if it's higher than that I wouldn't want to subject the cooling system to those high pressures.

EDIT: I should mention that my new (2nd) water pump is also leaking again, so experimenting further will have to wait until I get that straightened out...

 

[Blue Angel]

Looking at the images you provided, I'm assuming the numbers in the table are describing the duty cycle of the PWM heating element in the thermostat to control the opening characteristics, is that correct?

Also, in the original program there are 194F and 221F maps. In your proposed program there's also a 248F map. Does that get used also?

EDIT: What are the different RPM zones?

 

[carbon02]

Copied from my reply in the O Ring thread:

EDIT: I should mention that my new (2nd) water pump is also leaking again, so experimenting further will have to wait until I get that straightened out...

After your last change and potential issues I assume your changing the pump this time? Or a different dealer?

If so I'd be interested in some thoughts for supporting the engine. I was under the car about a month ago removing the full factory splash shield to service the automatic transmission fluid. I didn't see a good jackpoint from the underside. I'm not keen on a block of wood on the oil pan.

 

[Stingray1974]

Problem fixed! I made these programming changes to my Cruze ECO.
I have not had any coolant loss since the change.
I think all Turbo units can have the same problem since all Cruze ECO's have the same program from GM.

 

[Blue Angel]

Stingray, did you see my questions above in post #14?

 

[Stingray1974]

No I did not see post #14, I'll try to find it.

 

[Stingray1974]

Yes, the numbers in the table are the PWM duty cycle to the cooling fan. I'm not sure, it may also be tied to the electronic thermostat to control flow, but it works!

In the original program there are 194F and 221F maps and a 248F map that is not used so I just duplicated 221F map as they did before. There are several torque zones tied to this map also but I really didn't worry, they are as before. I have monitored my car after the change and now it stays right where it should. Before my temperature went up over 240F now I have not seen over 228F. I have driven around town and back and forth to Alabama in 98 degree temperatures and I have not had any coolant loss or odor as before.

I can send you the torque and RPM zones if you wish. This was not a concern to me as it is clear the 221F mode factory program waited till it was already hot before it aggressively set the PWM to cool. This is strange and doesn't seem to match any other cars ECT profile. It was not logical that they would call out a 221F mode and set the parameters to allow it to get much hotter. My change just does a better job of keeping it at the desired 221F.