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My wonderful wife. She's not a Subaru lover. Kind of a trade off - she got the Honda - I got my Cruze .:) I really liked the drive, build, and economical stats about the Cruze.
Cool. I'm also considering the VW Golf. It seems to be more reliable than the other VWs and the interior wasn't dumbed down like the Jetta.
I still want to wait until the end of the year to see what the 2014 Cruze is like.
 

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VWs =/= reliable. The 2.5 is more reliable than the TDI and 2.0T, but it's still a VW and they are plagued with electrical nightmares. Too bad. They're very much drivers cars and fantastic to drive. I love the Golf - woulda bought the TDI if it weren't $26,000.


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VWs =/= reliable. The 2.5 is more reliable than the TDI and 2.0T, but it's still a VW and they are plagued with electrical nightmares. Too bad. They're very much drivers cars and fantastic to drive. I love the Golf - woulda bought the TDI if it weren't $26,000.


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Thats why I never considered them but the Golf does intrigue me. I'll do more research on reliability-I would buy the 2.5 if I went for it.
On thing I love about the Golf-lumbar controls in the seat, plus I like the teutonic dashboard and the fact they have been making them for years at the same plant in Germany
 

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More "progress" with investigating this issue.

I went out at lunchtime at work yesterday to run an errand and left the heater control set to full cold the whole time to get the car nice and hot. It was snowing quite heavily yesterday also, so pushing the car around through deep snow is extra work for this little engine and gets it heated up real quick. When I got back into my underground parking I sniffed around the edge of the hood and could smell coolant.

So on my way home from work yesterday for the last 10 minutes of my drive I set the heater to full cold again to get the car as hot as possible. I pulled into the garage and shut the car off, immediately popped the hood and recorded this video (you might have to turn up the volume a bit to hear it properly):

Boiling Coolant 2 - YouTube

Low and behold, beneath all of the popping and creaking of cooling metal parts (which is normal by the way) you can hear the sound of air bubbles making their way through the turbo/oil cooler coolant feed line. This means there IS localized boiling of coolant in either the turbo or oil cooler, and I'd put my money on the turbo being the culprit.

NOW BEFORE WE JUMP TO ANY CONCLUSIONS, all I've shown here is that there's enough residual heat in the turbo after shutting the engine off to boil the coolant inside of it. Whether or not the turbo actually boils coolant while the engine is running is another question I'm not sure I'll be able to answer, but I will offer this information. I was driving the car very easily at low speeds (without the heater going) on clear plowed roads prior to parking it in the garage, and was doing so in -12C (10F) weather. When I opened the hood there was a very faint smell of coolant, not strong at all but it was there. I could not detect any vapour escaping from the vent on the overflow tank. I would guess that someone blasting down the interstate at 80 MPH on a 100F day would be introducing thermal loads far greater than what I have done here.

Whether the Oil Feed TSB discussed above has anything to do with this issue I don't know, but it certainly seems like the two could be related (reducing either oil or coolant flow to the turbo will cause it to heat up more). It would be interesting to see someone with the coolant vapour problem have the TSB done and report back their findings. I will be contacting my dealership to see if the TSB applies to my car, and if it does I will try to get them to show me the whole TSB so I can understand exactly what is going on with the fix and what it does and does not address. If the turbo is boiling off the coolant in it after the engine shuts down, the turbo's center section could be getting hot enough to "coke" oil in the bearings and feed lines.
I had a similar coolant sound this fall. With the engine really cold I removed the radiator cap and added about 2 cups of fluid. Since then I have not heard this coolant sound. I had thought it was air in the coolant system.

I've popped the hood and smelled the engine compartment every day for the last month after coming home from a 30 mile drive. My bottle is also showing signs of venting with water marks on the plastic similar to the pictures above.

I thought adding coolant addressed that boiling coolant sucking sound.
 

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I thought adding coolant addressed that boiling coolant sucking sound.
I haven't topped off my coolant yet, it is still a little low. I'm planning to pick up some distilled water tonight and top it up.

With the reservoir at a higher level, the system pressure should be higher since there is less air to compress. It is possible that the higher pressure could raise the boiling point of the coolant slightly, which could reduce coolant boiling in the turbo. I don't think it would eliminate it, but it could reduce it.

Another thought is that maybe the coolant level drops (venting after shut-off) until the volume of air in the overflow is great enough to allow the turbo to boil coolant without pushing the system pressure above the cap relief pressure. Hmmm... I will have to check this out. Every time I've shut the car off and checked for venting I haven't seen it happening, but my reservoir level was already low. If I top off the reservoir and the venting starts after shut-off, this could be it.

I can smell coolant when I pop the hood even with the engine running, but the smell does not seem to be coming from the overflow. It seems to come from the hot water outlet from the cylinder head area, since putting my nose down around the vent tube to the overflow seems to get the most potent smell, but that said the smell is still pretty slight, not strong at all. My coolant level has not appeared to drop since I started checking it.
 

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Smell locations can be quite misleading in a hot engine bay. Just saying.

Also, I'm not too sure if the coolant is actually boiling. You can achieve a pretty effective thermal siphon without reaching boiling temperatures, which by the way are very high for antifreeze/coolant.

We have identified the water pump as a known issue where a pinhole leak exists (may not even be big enough to notice). That will certainly be the source of some peoples' problems. Between that, the grease in the HVAC box, and the overflow tank relieving excess pressure from the system right near the HVAC intake, it's not exactly a simple identification of the problem.

We aren't aware of any other leaks in the engine bay aside from that water pump.
 

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I haven't topped off my coolant yet, it is still a little low. I'm planning to pick up some distilled water tonight and top it up.

With the reservoir at a higher level, the system pressure should be higher since there is less air to compress. It is possible that the higher pressure could raise the boiling point of the coolant slightly, which could reduce coolant boiling in the turbo. I don't think it would eliminate it, but it could reduce it.

Another thought is that maybe the coolant level drops (venting after shut-off) until the volume of air in the overflow is great enough to allow the turbo to boil coolant without pushing the system pressure above the cap relief pressure. Hmmm... I will have to check this out. Every time I've shut the car off and checked for venting I haven't seen it happening, but my reservoir level was already low. If I top off the reservoir and the venting starts after shut-off, this could be it.

I can smell coolant when I pop the hood even with the engine running, but the smell does not seem to be coming from the overflow. It seems to come from the hot water outlet from the cylinder head area, since putting my nose down around the vent tube to the overflow seems to get the most potent smell, but that said the smell is still pretty slight, not strong at all. My coolant level has not appeared to drop since I started checking it.
Dropping the coolant level to the bottom of the arrow seems to have stopped the venting through the cap/tube for me. When it was higher, there was constantly a coolant smell any time it got up to temp from the teens - 40F.
 

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My Cruze was delivered new with coolant in the reservior tank just covering the outlet hose on the bottom of the reservior tank. With new car designs the coolant addition point is not neccessarly the highest point of the coolant system. They are filled via vacuum at the factory, and getting coolant to simply flow by gravity from the radiator cap area has become more difficult.

The old coolant bottles used to have a full cold line, and a full hot line. With the cruze I only see one arrow, which in my opinion is really hard to see.

I agree that probably filling the bottle cold all the way up to line cold may cause excess bleeding when it gets hot.

A 50/50 mixture with a 15 psi cap boils at 265 psi I believe. The cruze is a 20 psi system with even more safety cushion.

I see that Rockauto has Coolant Caps for the cruze. Has anyone tried an aftermarket coolant cap? For $5.00 I may add one to my next order just to try it.

I always thought having a coolant cap release, caused the internal springs in the cap to wear, and not hold pressure again.

However others have gotten original GM cap replacements and have seen similar issues reoccur.
 

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Smell locations can be quite misleading in a hot engine bay. Just saying.
Yep - I'm being really general. When I put my nose right up to the vent on the overflow I can't smell anything, but hovering my nose around the small coolant tube that runs from the hot water outlet to the overflow reveals a very slight coolant-like smell. This is generally over the hot water outlet on the side of the cylinder head where four hoses and a coolant temp sensor all hook into the outlet, and the outlet itself mounts and seals to the cylinder head. Lots of potential there for a leaky joint, but I won't get worried about it until I get a closer look down there.

For all I know what I'm smelling could be the smell of the coolant seeping through the rubber hose... it's very faint, but is only noticeable in that area.

Also, I'm not too sure if the coolant is actually boiling. You can achieve a pretty effective thermal siphon without reaching boiling temperatures, which by the way are very high for antifreeze/coolant.
Did you get a chance to see the video I posted? In the video you can clearly hear bubbles travelling through the turbo's coolant supply line. What you can't hear in the video is the low rumbling "hiss" of the coolant boiling inside the turbo. It sounds kinda like a block heater.

The next time you drive your car, turn the heat off several minutes before getting to your destination to get her nice and hot, turn off the ignition, pop the hood and stick your head down by the manifold. Within about 30 seconds or so from turning off the engine you'll hear a noise similar to a kid trying to slurp the last few drops of his drink out of the bottom of the glass with a straw. Then listen closer, beyond all the clicking and popping of cooling metal, and you'll hear the boiling coolant in the turbo. You'll need to be in a quiet environment to hear this, I didn't notice it until I listened in my garage with the door closed.

I did a quick Google search on this and it seems to be quite common in turbocharged vehicles. Yes, the boiling point of coolant is quite high (~265F), but the temperature of exhaust parts is much higher than that. Once the heat soaks in the coolant will boil.
 

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Dropping the coolant level to the bottom of the arrow seems to have stopped the venting through the cap/tube for me. When it was higher, there was constantly a coolant smell any time it got up to temp from the teens - 40F.
Well, this would back up my theory. I'm going to do a little experimenting. My coolant is low, but for all I know the level dropped quickly when I bought the car and hasn't moved in a while. I will post my findings.
 

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I did a quick Google search on this and it seems to be quite common in turbocharged vehicles. Yes, the boiling point of coolant is quite high (~265F), but the temperature of exhaust parts is much higher than that. Once the heat soaks in the coolant will boil.
Considering that turbos can reach darn near the temps of exhaust valves (800-1400 deg F), depending on the load, that makes sense.
 

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My Cruze was delivered new with coolant in the reservior tank just covering the outlet hose on the bottom of the reservior tank...

...However others have gotten original GM cap replacements and have seen similar issues reoccur.
I'm one of them... both of my Saturns and my Corvette used the same type of tank cap, and I've had to replace them on both cars. In both situations they allowed water vapour to escape, letting the system go low. The 'Vette went low enough that air got into the system, the pump cavitated and the car started overheating on me on the highway.

EDIT: I haven't checked, but it's possible the Cruze still uses the same cap design? I'll have to look when the 'Vette comes out fo rthe summer... I hope not!

Interesting about the coolant level on delivery. Mine is a '12 also, and I never thought to look at the coolant level when it was new. When was yours built?
 

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I'm one of them... both of my Saturns and my Corvette used the same type of tank cap, and I've had to replace them on both cars. In both situations they allowed water vapour to escape, letting the system go low. The 'Vette went low enough that air got into the system, the pump cavitated and the car started overheating on me on the highway.

Interesting about the coolant level on delivery. Mine is a '12 also, and I never thought to look at the coolant level when it was new. When was yours built?
Mine was low from the factory (just above the neck). 10/11 build date. Not sure if it ever LOST any coolant - that's just where it was to begin with when I first looked ~3000 miles. Smells began when I topped it off.
 

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The fill point in the Cruze is the highest point in the coolant system. You definitely need more coolant because your coolant level is so low that air will be sucked into the cooling system.
 

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I have a 2013 eco mt on order, and this thread is really causing me to pause. Sounds like this is a common issue, and there is no final fix from GM. I really was impressed with this car during my test drive, and research, but should I think twice about this purchase? Is this the same old crappy GM quality?
I thought twice about it. I'm waiting here to see what the resolution of the issue is before I plunge in with a purchase. I don't need a $20,000 headache.
 

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The fill point in the Cruze is the highest point in the coolant system. You definitely need more coolant because your coolant level is so low that air will be sucked into the cooling system.
So long as it has an inch or two margin above the intake tube when cold, you're fine. It's more just an overflow tank in case there's really a leak somewhere. Liquid doesn't expand significantly when close to boiling, but there is a very small difference. That said, unless there is a leak, you'll never be sucking in air if the tank is filled above that hose.
 
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