2010 Aveo 218K

[Nemo]

This last year my perfectly running 2010 Aveo, with 218,000 miles on it, has been plagued with problems. I change the oil religiously & it burns just under half a quart of oil in 3500 miles. I do all my own maintenance and replace parts with OEM components whenever there's a problem. It's been a great car. But the past 10 months or so have not been kind to it. Typically I can troubleshoot and fix anything but these have me stumped.

Here is a run down of issues:

First problem:
Needed new rims as the tires kept loosing air.
Tire company replaced them with plain steel aftermarket rims.
Tire Pressure Sensor light would not go off even after several attempt to sync the sensors.
Was told the batteries in one of the sensors was going dead.
Replaced them all.
TPS still will not sync and the light is on all the time now.
I was told the ECM could be failing.
Note:
I can't put the wheel covers on as the rim shape is different.
Question: Could aftermarket rims screw up the signal? (I doubt it but thought I'd ask)

Second problem:
Engine started occasionally misfiring under light acceleration when traveling at speed.
From a standing start, smooth acceleration until about 3rd gear... then misfiring would start (again occasionally)
Let off the throttle and it would smooth out.
This has gotten progressively worse but still intermittent.

Third problem:
If I hit the 'Hold' button (when misfiring occurs) the transmission will down shift, engine RPM goes up and acceleration is smooth, far less to no misfiring. However within the last 700 miles when I go to turn the 'Hold' button off the transmission will not shift into the higher gears.
Shut the car off at a stop light and start back up and it shifts fine but the misfire returns.

Question: Could these symptoms be a failing ECM as stated earlier or is it more plausible that these are separate issues?
I did read that P0420 code can be caused by leaky fuel injectors putting too much fuel into the cylinders. Perhaps?

CODES:

1st CODE: P0420 Catalytic converter
(I followed the suggestion and sparked one up / felt much better but still have the code)

2nd CODE: P0300 Misfire (expected that with the rough acceleration)

3rd CODE: P0583 Cruise control circuit Low Voltage
Question: Could this be another sign of a failing ECM and contributing to the other problems or is it again more plausible that the control solenoid is failing?

NOTE: The last code ( P0583 ) just started with the occasional and progressively worsening misfire. Maybe 1500 miles ago.


Maintenance:
Plugs are 1 year old.
Coil pack brand new 2024-04-04
Exhaust and Cats: All new exhaust 1 year ago from the exhaust manifold on back.


I hate the idea of getting rid of Bullet. But is it time?

Nemo

[EAD15]

When was the last time you replaced the air intake hose (circled item in photo) from the air cleaner? If you never have I would bet you have a crack in it allowing unmetered air into the engine. Take off the hose and look carefully in each "fold" for a leak. Dorman sells a replacement for the intake if you find a crack.

If there is a crack, you can patch it with duct tape temporarily (make sure the tape goes deep into the fold) and use that opportunity to confirm that is the cause of your misfire while you wait for the part to arrive.

Edit: I had a random misfire and catalyst code in my 09 Aveo. Bought a new coil pack, replaced the spark plugs, downstream O2 sensor, etc and it got a measurably better but it wasn't until I was deep into an unrelated repair and removed the air cleaner assembly that I found the crack in my hose. I suspect that was my problem all along

[Nemo]

EAD15,
I did in fact replace that hoses about 3 or 4 years ago but thanks for reminding me. I will go check that tonight and see what I find. When I replaced it I was changing air filter and found a crack on the bottom of the hose completely out of sight. Worth looking at again. I'll report back with what I find.

[Nemo]

When was the last time you replaced the air intake hose (circled item in photo) from the air cleaner? If you never have I would bet you have a crack in it allowing unmetered air into the engine. Take off the hose and look carefully in each "fold" for a leak. Dorman sells a replacement for the intake if you find a crack.

If there is a crack, you can patch it with duct tape temporarily (make sure the tape goes deep into the fold) and use that opportunity to confirm that is the cause of your misfire while you wait for the part to arrive.

Edit: I had a random misfire and catalyst code in my 09 Aveo. Bought a new coil pack, replaced the spark plugs, downstream O2 sensor, etc and it got a measurably better but it wasn't until I was deep into an unrelated repair and removed the air cleaner assembly that I found the crack in my hose. I suspect that was my problem all along

Ok so I checked the intake hose and it looks great yet. So no unmetered air getting into the system.

[EAD15]

Darn, there goes the easy fix. What's strange I don't find the P0583 trouble code in the factory manual's DTC diagnostic code info for the Aveo. Google provides an answer but one that doesn't make sense because the cruise control is electronic, the throttle actuator is electric (as far as I know), so a vacuum control circuit code is confusing

[Nemo]

Update on the misfire:
So having upgraded to iridium plugs at 180,000 they had under 35k on them. I new they should be fine. Replaced the coil pack as it has a lifetime warranty so figured replace that to make sure. Still misfire on cylinder 2.

That only left fuel injectors. SOÂ…

I pulled the fuel pump relay fuse, started the engine and let it stall out. Checked the rail for pressure and it was a zero. Pulled the rail and injectors off. It was a bit tough to get them out but working each end of the rail a little at a time they finally popped free. Then separated the injectors from the rail.

I clean them with carburetor cleaner using the following method.

Take two lengths of wire (I used 16 gauge) about three feet long. Put an alligator clip at each end. Connected one end of each wire to each post in the injector electrical connector. Connected one lead to the positive post on the battery.
Took an 8 inch length of fuel line that fit snuggly over the inlet side of the injector. Filled the line with carb cleaner, stuck the tip of an air nozzle into the fuel line and held it there putting just a bit of air pressure against the injector. The had a friend take the negative lead and tap it on the negative terminal on the battery. As it opens each time the carb cleaner shoots out the injector.

The cylinder 1, & 3 injectors looked like a nice fine even fine spray. Cylinder 4 was more stream like than 1&3 and cylinder 2 looked really bad. It shot out about the size of a pencil lead. As I continued the process the pattern changed from a tight small stream to a wide fan mist like the other injector. L

Convinced I had found the problem I put them back in the car with new o-rings making sure to place the injectors in a different location they came out of. My thought was if there was still a problem and it was tied to the injector the issue should show up on a different cylinder.

It ran significantly better. Much better response and acceleration. But there was still a slight misfireÂ… not nearly as bad but still missing.

Thinking there was no way it could be plugs I pulled them out of the engine. Holy bovineÂ… plugs from cylinder 1,3 & 4 looked brand new yet. Cylinder 2 was totally shot.

Put in a new set of plugs and Bullet runs strong and sails down the freeway.

What I believ was the cause:
I believe the misfire problem started from a clogged injector. Because I took far too long to asses the problem by the time I got to it the spark plug was ruined from running it too long without enough fuel getting to the cylinder. The plug overheated and burned out the electrode.

Thank you EAD15 for your input.


The 0583 error code has also disappeared.
Now I have two thermostat codes that I need to deal with.

I hope this helps some one in the future!