2016 Checy Sonic Problem

Status
Not open for further replies.
Joined
Feb 26, 2011
Messages
1,232
Location
N. Georgia Mtns
Two weeks ago this past Friday, my neighbor's wife's Chevrolet Sonic overheated on the way home from Asheville, NC. Saturday morning he asked me if I'd go help him replace a radiator hose that was spewing anti-freeze he had found when he went to get his wife. I said sure. So we headed up the mountain to the parking lot of a small church he had parked it in. We changed the hose, and topped it off with anti-freeze. I told him I would follow him back home. We only got about four miles when it began overheating again so he pulled as far off the road as he could given our location in the mountains. Nothing was leaking. He asked what else we could do to keep from having the vehicle towed. I said the only thing I could think of that I had the tools for, and would be my next best guess would be the thermostat. He said lets do it so we fought through all the obstacles to reach the thermostat and removed it. We drove to the nearest town and bought a replacement. After baking in the sun for a few hours, and grabbing our backsides every time someone drove by us on the side of the road since we were so close to the shoulder, we got the thermostat replaced. We buttoned everything back up and made it back home. The car seemed to run fine, no overheating, and we assumed everything was OK.

Sunday morning he called me and said the car wouldn't start. He told me his wife had just replaced the battery a few days earlier. I drove down to his house, tried to jump start the car to see if maybe she got had gotten a bad battery. The battery seemed to be good. The starter was engaged but the car wouldn't start. Then in subsequent tries, the starter quit engaging completely. Bad starter?
21.gif
That lasted for a few minutes until the starter started to engage again. I'm no mechanic, just someone with some basic knowledge. I assumed he had spark since the engine was trying to turn over. I checked for fuel and pressure from the bleeder valve on the fuel rail and there was fuel and it shot out strong so I assumed things were good there. Air filter was clean. I told him that, unless the starter was indeed bad, that was about all I could think of.

On Monday he had the car towed a few miles to an old school mechanic. After looking at the car, he told my neighbor he thought the car had a bad head gasket due to the overheating from the week before. ****And this is where I was really hoping someone here on BITOG could help with.**** He said he didn't want to replace the head gasket until he found out if anything had to be done to the car's ECU after the head gasket got replaced (He told my neighbor he didn't have the equipment necessary to do that). He told my neighbor that the car's ECU should have been re-programmed after the battery was replaced and that could have been a contributing factor to the overheating.

Does this make sense to anybody? Or am I just too darn old and not up with current battery replacement technology. What might be a reason for a car's ECU to be re-programmed after replacing the battery, or head gasket? Sorry for the long-winded narrative but I felt the whole story would help. If you have questions, please ask since I may have forgotten something in the narrative.
 
My money is on coincidence.

I've seen nothing on-line that indicates there is a special ECU step for battery replacement.

Sounds like the mechanic just doesn't want to work on it.

Is the car still under a powertrain warranty? Maybe Chevrolet is on the hook for a head gasket if that is the case?
 
I have never heard of the ecu reprogramming after the battery replacement. I think its false. Maybe it has something to do with the ecu completely powering down on a battery replacement but i don't see why that would matter. As for the overheating i don't think the new battery could have any correlation to the cooling system.
 
I wouldn't let that guy fix the car he probably has no experience with aluminum heads and MLS gaskets. The head likely needs to be planed
 
If I had a vehicle that overheated and then wasn't able to crank the next morning, I'd think it was the head gasket leaking into a cylinder and pseudo hydrolocking it overnight.

I'd bring it to a better mechanic. Sounds like he is the type that changes spark plugs and changes brake pads. No actual diag or hardcore repairs.
 
He will be lucky if the connecting rod is not bent. The head has to come off, and probably be checked for flatness, I bet it is no longer flat. If it is a aluminum block, the top of the block may no longer be flat either. Then rebuild time. Disassembly, straighten, milling the head, most likely rather than wait the mechanic will get a reman head, with warranty.

There are probable timing sensors in the head, so the ECU has to be reinitialized to them. Even installing the same head, because the clearance is now different, it will need reinitialized. This is not reprogramming, it is a learn process for the sensor. Requires a pro scan tool. Not the things that sell in discount stores.

Find a better mechanic. Prepare for a large bill. If rod is bent, block warped you need a reman engine. It may now burn oil, this is because when it overheated a bore distorted. So reman time.


Rod
 
I can't imagine the ECU needing to be reprogrammed on this model--AFAIK even the BMW's will crank after a battery swap, the ECU just has to be told that the battery is new so it won't cook the battery.

OP, when you tried to get it to start, did the engine spin at all, or did the starter just go clunk? If it did spin, did it speed up at any time? Like it may have fired once or twice, or just spun faster?

If it wouldn't spin at all, then I'd guess hydrolocked, and pulling the spark plugs would prove that (pull, crank motor over, watch the geyser). If it was spinning, there is a chance that it has a bent rod as a result. But the other cylinders should fire... unless if timing somehow jumped or other massive mechanical damage occurred. If it did put coolant into the cylinder I would think it could be seen on the dipstick; maybe it could but not show there or in the coolant tank.
 
Originally Posted by Chris142
. Find a real shop.


Good luck around those areas. North Georgia, Western North Carolina, and Western South Carolina have mostly nothing but hack mechanics and crooks, even at the dealerships or indy shops. There are almost no reputable places to be found around these parts. Period.
 
Last edited:
Originally Posted by supton
I can't imagine the ECU needing to be reprogrammed on this model--AFAIK even the BMW's will crank after a battery swap, the ECU just has to be told that the battery is new so it won't cook the battery.

OP, when you tried to get it to start, did the engine spin at all, or did the starter just go clunk? If it did spin, did it speed up at any time? Like it may have fired once or twice, or just spun faster?

If it wouldn't spin at all, then I'd guess hydrolocked, and pulling the spark plugs would prove that (pull, crank motor over, watch the geyser). If it was spinning, there is a chance that it has a bent rod as a result. But the other cylinders should fire... unless if timing somehow jumped or other massive mechanical damage occurred. If it did put coolant into the cylinder I would think it could be seen on the dipstick; maybe it could but not show there or in the coolant tank.


When I first got there on that Sunday morning, it was trying to turn over (starter engaged the flywheel and tried to start). Then oddly, after a few tries, turning the ignition produced nothing but a whining sound but no engagement by the starter to the flywheel. After maybe ten tries, the starter started to engage the flywheel again but wouldn't start. And I apologize, it is a 2014 not a 2016 Chevy Sonic (not my car). Since we've been here only a few years, I haven't needed the services of a mechanic so I couldn't recommend one to him. I can't try some of your suggestions since the car is no longer at his house. I have no idea how he found the mechanic he had the car towed to. I just tried to lend a hand since they are struggling financially at the moment.

This brings up another question on my part. We drove approximately 50 miles home after changing the thermostat and it seemed to run fine. Could it have made it that far if the head gasket was bad or the head warped? Just asking. Again, I am not a mechanic.
 
Originally Posted by AC1DD
Originally Posted by Chris142
. Find a real shop.


Good luck around those areas. North Georgia, Western North Carolina, and Western South Carolina have mostly nothing but hack mechanics and crooks, even at the dealerships or indy shops. There are almost no reputable places to be found around these parts. Period.

I was going to start a thread on this very subject after reading the responses to this thread. Just what can one look for in hopes of finding a competent mechanic to handle problems I can't solve myself? I watch YouTube videos of some mechanics that seem knowledgeable and thorough and think to myself I wished I could find someone like that. There are many on this site that I feel fit that mold (don't want to mention names for fear of leaving someone out) and I would love to live in the same community and know I could get that kind of expertise and dedication. If you were in my shoes, new to an area and haven't needed a mechanic yet, what would you look for when the time came?
 
Why do so many people seem to have overheating problems ?

May be time for the OP to look for a salvage yard engine ?

We have a 2015 Sonic 1.8l .

The earlier models were known for throwing codes for the tstst . So far , ours is OK . Thank God !
 
Status
Not open for further replies.
Back
Top