2012 Chevy Sonic 1.8 - Cooling Systems Problems - Advice Sought Regarding Repairs

[Number_35]

My friend was driving his 2012 Sonic on the highway yesterday when the temperature light came on. (There's no gauge.)

He and his wife caught a ride into town with their daughter. He and I went out in the evening to check it out.

One of the heater hoses had blown. The blown hose, the other heater hose, and the hose from the coolant reservoir to the radiator were all very soft.

There is a lot of sludge in the coolant reservoir, and a lot coming out of the blown heater hose.

We went out again today with tools, and were able to isolate the heater core by clamping the intact heater hose closed, and clamping the blown hose on the engine side of the blown-out portion. We poured in quite a bit of tap water. Unfortunately in trying to find a solution I broke part of the plastic nipple off the thermostat housing/water outlet, which was very brittle. Fortunately there was enough left to clamp the hose section onto.

We were able to limp the car back into town. He drove at around 50 - 60 km/hr with 4-way flashers on, and I drove behind with my 4-ways on. We stopped once to check - the clamps were keeping the coolant in, and the engine seemed to be staying within its design temperature. (At the stop I transferred my ScanGauge to the Sonic. The temperature on the rest of the way home varied from about 85 C to 100 C. Given that the diluted coolant wasn't giving anywhere near full boil-over protection, I am glad the mostly-water coolant didn't get any hotter.)

Anyway, I now plan to replace all of the hoses (including the upper and lower rad hoses) and flush the system to get all of the goop out. It is really bad. Recommendations on a good product to use?

As well, I want to replace the plastic thermostat housing/water outlet I damaged. I don't know if this is inevitable that plastic cooling-system parts get brittle, or whether the plastic might have deteriorated due to the goop in the cooling system.

As far as the part, I'm trying to decide between the AutoTechnica and the AC Delco part. If it were my car, I'd go with the Delco part, but money is a big factor for my friend. Has anyone here any experience with the AutoTechnica part?

**************

Many thanks for your thoughts on this.

 

[Rand]

Generally I try to use oem or at least the oem maker of the parts.. but acdelco.. do they even make anything?

I think in this case going cheap might not be the right answer.. hes already avoiding dealer labor etc.
40$ more for the oem part.. I think is the way to go, but I dont have specific information on this part.

 

[xgmad]

Bluedevil flush is good stuff, will help get the goop out of the system.

Sucks that this happened, 2012 was a good year for a lot of things.

 

[atikovi]

A 2012 should have had at least two coolant changes by now, and I'm assuming it's had none from your description of the sludge. Unless it's contaminated with oil or transmission fluid, I'd just use water to flush and distilled the last few times. If it's an automatic, it's not uncommon for the cooler in the radiator to leak transmission fluid into the coolant. I'd find out what kind of sludge it is.

 

[Number_35]

Generally I try to use oem or at least the oem maker of the parts.. but acdelco.. do they even make anything?

I think in this case going cheap might not be the right answer.. hes already avoiding dealer labor etc.
40$ more for the oem part.. I think is the way to go, but I dont have specific information on this part.

Plus he's already avoided the towing cost. That would have cost a bit.

 

[slacktide_bitog]

Dorman and SKP have one with a metal cover instead of plastic

Flush all the coolant out with some flush, then refill with Peak 10x

 

[Rand]

yes it is dexcool takes about 6.3Qts and has a 150000 mile interval.. or 5 years.

Sounds like it has turned into dex-turd.

Flushing can be time consuming esp. if it isnt your vehicle.

 

[Number_35]

A 2012 should have had at least two coolant changes by now, and I'm assuming it's had none from your description of the sludge. Unless it's contaminated with oil or transmission fluid, I'd just use water to flush and distilled the last few times. If it's an automatic, it's not uncommon for the cooler in the radiator to leak transmission fluid into the coolant. I'd find out what kind of sludge it is.

I believe my friend added a generic coolant at some point. There are horror stories about mixing Dexcool with certain other formulations.

I'd love to check the ATF, but it's a sealed transmission with no dipstick.

 

[Number_35]

Dorman and SKP have one with a metal cover instead of plastic

Flush all the coolant out with some flush, then refill with Peak 10x

I saw those, but am concerned on two counts:

1. Dorman's reputation

2. The non-factory internal thermostat in anything other than a GM replacement part

 

[Number_35]

yes it is dexcool takes about 6.3Qts and has a 150000 mile interval.. or 5 years.

Sounds like it has turned into dex-turd.

Flushing can be time consuming esp. if it isnt your vehicle.

Only 140K km (c. 87K miles) on the car, but it's been on the road 11-1/2 years now - certainly over on a time basis.

 

[JohnnyG]

Be careful with the flush. GM was a big fan of stopleak for a while. Just make sure that "goop" isn't just leftover stop leak and is supposed to be there. The good thing is, you can always add more if you find out it's supposed to be there.

Or, somebody may have added stop leak themselves, in which case it might have other issues.
Someone should know if Dexcool, mixed with ANY other specific coolant will cause sludge. I am not aware of any combination that will do that. Other issues, yes, sludge, never heard of it.

A lot of people seem to think that adding stop leak to the coolant reservoir is a good idea. Since that is a minimum flow area, that doesn't work at all. Stop leak of any kind, needs to go into the block to be effective. The insertion point is generally the lower radiator hose, on the suction side of the water pump.

 

[slacktide_bitog]

I saw those, but am concerned on two counts:

1. Dorman's reputation

2. The non-factory internal thermostat in anything other than a GM replacement part

In that case, buy the metal housing from Dorman and SKP and remove the thermostat that came with it and put on an OE thermostat. Put the OE thermostat on the metal housing

 

[Number_35]

@clinebarger, I had a vague recollection of you saying something about cooling systems with the Chevy Sonic, and found this:

https://bobistheoilguy.com/forums/threads/what-are-you-working-on-today.331303/page-100#post-6053963

I feel less guilty about damaging the thermostat housing after reading your post, though it did look pretty deteriorated anyway.

Are there any plastic cooling system parts I should change out when doing this repair?

Thanks!

 

[14Accent]

@clinebarger, I had a vague recollection of you saying something about cooling systems with the Chevy Sonic, and found this:

https://bobistheoilguy.com/forums/threads/what-are-you-working-on-today.331303/page-100#post-6053963

I feel less guilty about damaging the thermostat housing after reading your post, though it did look pretty deteriorated anyway.

Are there any plastic cooling system parts I should change out when doing this repair?

Thanks!

Absolutely don't feel guilty. The cooling systems on ALL Sonic's are trash, be it a 1.4T or 1.8. After 100k, simply breathing too hard on one of the plastic components will result in failure.

My opinion? Replace everything. Heater hoses, upper/lower radiator hoses, the degas bottle, any and all housings/thermostats.

 

[Number_35]

Here's the Sonic stranded by the side of the highway on Tuesday evening.

Here are the heater hose connections to the heater core at the firewall. I am really annoyed that the hose clamps are turned such that it will be very difficult to remove them.

If the ears on the top one were facing up rather than down, and if the ears on the lower one were facing out rather than toward the firewall, it would be much easier to remove them.

Considering using a C-clamp to try to open them up. @14Accent, suggestions? Is there a special tool you use? I guess a Dremel if all else fails, but I'd be afraid of cutting into the heater core fittings.

 

[Number_35]

Here's the ruptured heater hose. The plastic connector on the thermostat housing (still intact at this point) is at the lower left.

I wish I'd gotten a photo of the globs of slime that came out of the heater hose.

 

[Number_35]

Here's my crude (but ultimately effective) method of blocking off the upper (and still intact) heater hose.

 

[Rand]

IMO dexcool eventually turns into goo sludge it can be normal.. when neglected severely.
I've seen it several times in cars that had nothing added (stop leak etc)
In one it was also run slightly low .. radiator about 90% full.. on a chevy 3.1 and it was exceptionally bad.

 

[Number_35]

And here's the lower (ruptured) heater hose, folded over and clamped to seal it. I cut the hose closer to the heater core, and cut off the damaged portion, and then installed one of the new ends over the damaged nipple on the thermostat housing. There was enough left to fold over and clamp as shown. Hokey, but good enough to limp the car home without losing coolant or overheating.

And how did I break off a piece of the nipple on the thermostat housing anyway? I had brought a new section of hose out from town. It was way more rigid, and I was unable to clamp it shut enough to not leak.

When I removed it, a piece of the nipple came with it. That was a terrible moment. I thought it was tow truck time.

However, the burst hose was so soft that it was easy to slide it farther over the nipple. I used a common worm-gear clamp rather than trying to reuse the original.

 

[14Accent]

View attachment 150292
Here's the Sonic stranded by the side of the highway on Tuesday evening.


View attachment 150293
Here are the heater hose connections to the heater core at the firewall. I am really annoyed that the hose clamps are turned such that it will be very difficult to remove them.

If the ears on the top one were facing up rather than down, and if the ears on the lower one were facing out rather than toward the firewall, it would be much easier to remove them.

Considering using a C-clamp to try to open them up. @14Accent, suggestions? Is there a special tool you use? I guess a Dremel if all else fails, but I'd be afraid of cutting into the heater core fittings.

Why are you trying to release the clamps? I could be wrong, but those look like quick connect fittings. Use a pick tool to lift the metal retainer surrounding the plastic fitting and pull.