Wow, this is crazy! Makes me want to go check mine, but now that I think about it, I don’t think I’ve ever removed that cap. Only the other two. Are you sure it was under pressure? Maybe the plastic cracked and caused the spring to pop the cap out of there? Is there any damage to the reservoir itself?

 

Actually, makes me want to ask my ex-wife to check the coolant.

 

Ok…I’m at AutoZone and the counter guy is a gear head, he said that this should NEVER happen unless there is a problem with the cooling system, as the radiator should not have built pressure like that overnight.

He did say to investigate this further as this could have sent me to the hospital, so keep an eye on why there’s that much pressure after sitting overnight (may be a bad head gasket or radiator).

The overflow tank is probably mangled too.

Either way, ordering parts now…hoping to get this thing back on the road soon.

 

Can’t tell you the reason coolant was low, but… the less coolant. The more air.

Same principle why they pressure test propane cylinders with water not air. Water will not compress.

Running less coolant (especially not enough to circulate) system gets super hot and the hot air is much more “explosive” when cap gives way than hot water.

Glad no one lost an eye.


Sent from my iPhone using Tapatalk

 

I looked in my driveway and I have a puddle of coolant about 12” wide and staining the ground (there’s no other water source and it is definitely Dex-Cool).

I tried to remove the remnant of the cap but it’s sucked into the overflow tank, and completely lodged in there.

I did go a gas station yesterday and a fellow motorist was trying to wave me down because I had a long trail of white smoke coming out of my car. YES the coolant overflow tank was full just yesterday.

So…if you had this 2012 Volt with a brand new $10k battery, $2k in transmission repairs, and $4k in suspension work, plus brand new tires and a few grand in other (maintenance/cosmetic) work, what would you do? Tow it to a dealer? Park it?

 

So…if you had this 2012 Volt with a brand new $10k battery, $2k in transmission repairs, and $4k in suspension work, plus brand new tires and a few grand in other (maintenance/cosmetic) work, what would you do? Tow it to a dealer? Park it?

You've had an incredibly bad streak of issue after issue with this car. It's been one thing after the other. Sell it in a sellers market?

 

Well, there’s some extreme pressure on the remnants of the cap inside the overflow tank. I tried to use pliers to pull it out but all it did was crack the plastic. And the long white trail of coolant smoke yesterday + coolant on my driveway leads me to believe something has failed in the engine or cooling system.

Sad that I was only able to enjoy this car for a year and just under 30k miles of driving. It really was a great car to drive. I’m parking it for now to get my thoughts together as I don’t want to make any impulse decisions.

The $299 lease deal from GM for a 2022 Camaro LT1 V8 (455HP) seems nice but I already have a RWD performance car and this would be redundant.

Maybe a Bolt or Bolt EUV might be in my future…

 

Eye protectors. 'nuff said.

 

Yeah. After the incident. Never expected the coolant cap to go flying out of there (in pieces, the spring went one way and the cap hit the hood), especially on a motor that was cold for 24+ hours.

I only noticed the coolant leak in the driveway after moving the car, it was too late…

Since nobody has the parts I need I’m parking this one for now. This has been one frustrating day and looks more like I’ll have to get this car towed to a dealer.

 

Dealer will write your car up for a head gasket replacement, at least. It has all the symptoms. Coolant is entering one or more cylinders, producing steam in the exhaust. High pressure combustion gases at 100 PSI more or less are pressurizing the cooling system. Combustion process contaminants plainly visible in coolant reservoir. To boot, it's leaking coolant.

If you're lucky, you won't have a cracked or warped head.

Would be illuminating to hear the maintenance history of this ICE. Has the coolant been changed? Run premium gas religiously? Previous issues that may have been a precurser to this issue?

Good luck.

 

Dealer will write your car up for a head gasket replacement, at least. It has all the symptoms. Coolant is entering one or more cylinders, producing steam in the exhaust. High pressure combustion gases at 100 PSI more or less are pressurizing the cooling system. Combustion process contaminants plainly visible in coolant reservoir. To boot, it's leaking coolant.

If you're lucky, you won't have a cracked or warped head.

Would be illuminating to hear the maintenance history of this ICE. Has the coolant been changed? Run premium gas religiously? Previous issues that may have been a precurser to this issue?

Good luck.

Thanks for the detailed response! I bought the car used with a little over 64k miles on it last August. I ran 91-93 octane religiously, only used 87 once when there wasn’t any other option available, and flushed the coolant twice - once after purchasing the car, and again right after (at a dealer) because the first shop didn’t use the EV-rated coolant (they just used regular 50/50 premix) which set off the High Voltage ground fault warnings and a CEL. So it’s only had the non-manufacturer spec’d coolant in it for a day (under my ownership).

I always took it easy when the engine was in the warmup phase, tried to do as many long trips as possible (to avoid carbon buildup), and only started doing local driving a month ago due to working from home.

The car is at the dealer now, hoping this can be fixed.

 

In terms of to fix or not, it depends on what the problem is and how much. As you know, I wouldn't have put that much into the battery, however this may be a simpler fix. Wait and see what the diagnostic is and make a knowledge based decision.

The used car market is a bit nuts right now with the shortages. I also recommend checking the current (vehicle repaired) value via Edmunds.com. It will be a good piece of information to have once you know what the issue is. There won't be a better time to sell this car than now.

 

What's the oil on your dipstick look like? Does it look like there's coolant in your oil? For that matter, does it look like there's oil in the coolant in your radiator?

 

It looked like oil however was very thin. I hadn’t run it much since the smoking (went to the gas station and then to a recycling center) so it seems like this is a recent occurrence, maybe within the past day from sitting. But I know a head gasket can’t just blow from sitting around. It hadn’t overheated before, or if it did, the temp sensor isn’t working properly.

I can’t tell if there is oil in the radiator, but the overflow tank looks a little cloudy. Not sure if it’s related, but when the cap blew up a bit of coolant shot out also. It was super cold, but definitely under pressure.

Car is at the dealer now. Everyone is telling me to get rid of it, this one seems like a “as-is mechanic’s special” which is probably why it sat on the used car dealer’s lot for so long.

I really do enjoy driving this car, just wish it was working.

 

Hmm, a blown head gasket would have left your plugs clean, not fouled as you suggested in another post. But, that said, this screams head gasket to me.

Frankly, you gave it a good go, it is time to walk away from this car.

 

Pressure in the cooling system when the engine is cold is a sign of head gasket failure, as is losing coolant and white smoke in the exhaust. Hopefully, you caught it early before any overheating caused a warped head and before coolant in the oil caused any mechanical problems.

 

I stopped by the dealer this am, they said it shot out more coolant just sitting overnight and something is (oddly) under pressure when it shouldn’t be. It did make a mess on their service driveway even though it hasn’t run in 2 days.

They are hoping to have a diagnosis soon, but this doesn’t look good - the coolant coming out of odd places (and tail pipe when running), lots of white smoke, extreme pressure in the cooling system, and occasional loss when it’s parked overnight seems like a head gasket issue.

Should know by end of day today, fingers crossed…

 

The hopeful news is that the leak is apparently minor. The leak you have appears to allow high pressure combustion gases to get into the coolant tank but doesn't appear to allow low pressures from the coolant tank to flow the other way (or the coolant tank pressure would equalize after sitting for a while). Therefore, it appears to be a small leak that only leaks when there's a lot of pressure at the failure point so there's hope that coolant hasn't flowed into the oil (which could cause premature engine wear).

 

i use a compression tester, remove check ball and apply 100 psi into combustion chamber and look for bubbles in coolant reservoir

 

Stick your finger in the exhaust pipe. Rub the liquid between your fingers. Coolant feels completely different than water. It is very slippery.

 

Will try when dealer releases my car. Currently have a 1 week lead time for the overflow tank. I called them back and they didn’t pressure test it, the service advisor was misinformed.

He says once they get the tank in then they will have to drive it a bit to see what happens when it’s warmed up. As of right now, no telling what it could be (but a head gasket would be $3,200-$3,500 if needed based on a few quotes I got today).

 

It won't be just a gasket. It will be gasket plus a head (or at least machining).

 

Yes, it’s either a new head or reuse the existing head with machining. A few quotes said they would also do the timing chain (if stretched or showing signs of excessive wear) for around $500.

As of right now we can’t even get the cooling system parts (1+ week lead time), so this is going to have to sit for now.

This should be a cautionary tale to anyone that buys a used Volt - inspect carefully!

 

When you use the engine, how long does it typically run? Does it run long enough to get fully hot?

 

Either 70+ miles (plenty to get hot in an hour of driving) or 1-2 miles past EV range. No idea how the previous owner drove it though.

 

If the car has no warranty, no need to get it done at the dealer. Used coolant tank, used head (or machine work), new timing chain, done. This is basic work for any decent tech, and can be done at home if you like.

 

I agree, I am only going to have the dealer replace the tank and flush the system.

I have pulled heads off motors before and the only thing I see myself needing help with is to get the timing chain set right. On the Ecotec 2.4 in Malibu’s, it’s really hard to get everything set “in time” with only one person.

But I do have a buddy that has worked on many engines before so I’ll probably ask for his help if I choose to DIY this and the issue turns out to be the head gasket.

Right now driving my LS powered car with 154k and it is running good for now…

 

Just for grins I went out and checked my cap and reservoir today. The cap unscrewed normally and the coolant level was correct.

 

Isn't the 1.4L gen 1 motor very similar to the Cruze 1.4L motor? If so, this video may be helpful:

 

Thanks for the good info!

I am torn on whether or not this car is worth keeping at this point. It’s been a dream to drive, but a nightmare to keep running. I just found this weekend that the VIN numbers were scratched off (except the main one under the glass) so I might have a 90k mile Volt with a 180k mile motor in it, and a bunch of the subframe parts look brand new.

Granted, it may run great after a bunch of repairs, but this thing has stranded me more than any other car I’ve owned (even some cheaper cars) so I’m really not sure what to do.

I already owe the dealer $440 + tax for the coolant overflow tank, only then will they pressure test it, and then it’s another round of $$$ for the additional diagnostics they want to do.

At this point turning this car into a lawn ornament sounds like the best option! I really just want to park this thing and hope someone would want the HV battery. Is there any resale value for just the battery?

 

If I were you I'd sell it, provided I could buy a new car I wanted at MSRP. Unfortunately, the market conditions right now are pretty bad. It's just not normal for a car with that mileage to have this many issues, unless the model year was a known lemon. It's obviously been abused by the prior owner, or had accident damage. Heck, I'll be hitting 100k on the 2017 within a month or two, and the only large issue was the BECM, which was covered under warranty. The only question in my mind would be to fix and sell, or sell as is. IMO, it's time to cut the losses.

 

It would be hard for me to walk away after spending all of that money on a battery. The engines for Volts are pretty cheap since it's usually the battery that sends them to the junkyard. I've seen them on LKQ for about $500.

 

Clublife, you have stated several times in various threads that you did not know how the car was treated before you bought it, and suspect it may have been abused after having many problems. Its obvious your car was abused and patched up to sell. You are so far in now (10+G in repairs) that you're damned if you do and damned if you don't in terms of paying for more repairs. This coolant tank/cap explosion is highly indicative of engine compression squeezing through a failure point in the cylinder head gasket. The only way to make this repair cost effective is to do it yourself. Definitely not for the faint of heart, but possible as the high voltage need not be touched. 12v battery disconnected, then pull high voltage disconnect under center console. You need a place to work and a knowledgeable friend(s) to help out. Or a competent mechanic that will do the job right without gouging another groove in your wallet.

 

With the amount of money you have in the car the most cost effective solution would be to rebuild the top end yourself. Having not rebuilt a motor in over 15 years I'm not sure how difficult it is to get parts and potentially have the head flattened. You would need to get a true flat-bar with a feeler gauge to verify the block is still flat (usually the head warps). If the block is not flat I would either part it out (including keeping the HV battery pack for a solar project) or just saying the closing statement at the end of The McLaughlin Group show.

 

Wow
More heartaches with that ___ car.
If the Senate passes the EV tax credit it would help getting a full EV car. Like a Bolt.

I believe the EV Leaf is still eligible for the 7500 credit.

In the meantime you could work on the Volt, if you have a dedicated garage for it. while driving the ICE. As I recall (from previous experience) the only way to tell for sure if you need a valve/ head job is too pull it off and inspect it. Maybe they have a way now. Scanners don’t give codes for that. But the signs are there.

 

So far NOTHING passes the smell test that everything is ok with a new coolant tank. Burn any gas grade you want as long as it's Top Tier. The idea the car's been abused doesn't stand up either. It is what it is and #### happens. But there are still some unexplained issues, like storing pressure for days? Burping after it's cold? Doesn't make sense - at all. But obviously it's happening. And there shouldn't be anything else attached to that coolant circuit but the engine.

If you've not had the cap off before on the old tank I'd say it sealed up over time and held a lot of pressure that had to come from the engine, probably through the gasket. I didn't check to see if you said that. If it's not building pressure in the new coolant tank it's operating fine. It's not SUPPOSED to hold air pressure. It is just a reservoir to allow the radiator to siphon water in and not air to avoid oxidation. But it doesn't mean your problem went away. It didn't.

I'll bet on the gasket and maybe the head. Unless you're REALLY unlucky, when you find the problem the rest of your investment will pay off.

 

If you've not had the cap off before on the old tank I'd say it sealed up over time and held a lot of pressure that had to come from the engine, probably through the gasket. I didn't check to see if you said that. If it's not building pressure in the new coolant tank it's operating fine. It's not SUPPOSED to hold air pressure. It is just a reservoir to allow the radiator to siphon water in and not air to avoid oxidation. But it doesn't mean your problem went away. It didn't.

Nearly all vehicle cooling systems are designed to build pressure, thus raising the boiling point of the cooling fluid. Look at the cap, I believe it is rated at 15psi. However, in this specific case(after the car had not run for a long while and was cold, there should not have been much (if any) pressure.