Hey guys,
I may have a throttle body issue with my 2010 Aveo. Here's the story behind why I think so, and I'm hoping someone may be able to help identify the problem.
So, originally I drove a 2009 aveo, which I was given after my brother bought his own car. It had been through a lot, and my dad said that they replaced the ignition coils 3 times, replaced the throttle body once, along with many other things. But once he bought his own car, I was given the aveo, and it seemed to be running great. I would typically squeeze 38-40 MPG out of it (it was the manual version), and it really never gave me issues. I loved it, but unfortunately I got hit in an accident where someone blew a stop sign and ruined the driver's side of my car. We had to buy another car. So, since I loved that car so much, we bought a 2010 Aveo (manual again).
I didn't notice anything funny about it during the test drive, but once we took it home I started noticing some things. First of all, it will buck in any gear at either the 1500 rpm range or around 1800 rpms. But it will only do so if you have the throttle in the right position, it seems to be if you lightly touch the pedal. It will do this in any gear, so I don't believe it comes from lugging the engine. Also, what is odd about that is that if you either let out the pedal, or push harder, the bucking stops. Also, the response time of the throttle is kind of slow. I noticed I would stall this car a lot, which is very unusual for me as I've been driving manual for so long. I realized that the pedal takes about a whole second before anything happens. So, I've adjusted my driving to work with it. What would happen is if I let out the gas and pushed the clutch in consecutively, like I've always done, the engine will jump up about 500 rpms, then slowly drop resulting in a rough shift unless you wait a long time. So, what I've been doing is letting out the gas, waiting about a whole second, then pushing the clutch in. And also pushing the gas pedal in way before I normally would when starting from a stop. The third issue I've noticed is how if you step on it, the car just drives odd in general. It feels like it doesn't just rev straight up, it almost feels like it revs up and slightly back down as it moves up the rpm range. For example, one time in traffic I had to get up and going, so I really stepped on it in first and the car had a very subtle bucking feeling, which is what makes me think that was happening. Also, I haven't been able to squeeze more than like 33 MPG out of it at best! I'm just not sure why it drives so different than the other Aveo we owned.
Since we've owned this new Aveo, we took it to a local shop for a tune up and they replaced the ignition coils. However this didn't fix most of these problems. The only thing it helped is that it idles a bit better now, and they claimed it was misfiring so I suppose that is taken care of. However it still bucks in any gear at either 1500 or 1800 rpms with a light touch on the pedal, it still isn't getting the mileage I was used to getting (I'm very conscious of how I drive, that's how I would squeeze 40 MPG out of the 2009 aveo) and also, it just doesn't feel right. Like I said, it doesn't seem to rev right up, it feels like it kind of revs up and down subtly as it makes its way up.
I also cleaned the MAF sensor just because it is easy to do and supposedly a dirty MAF will result in that slow response time. It again helped the idling, but not the driving. That is why I think it is the throttle body that needs to be replaced.
So, I'm wondering if any of you on here have dealt with a similar issue in your Aveo, or if you could help me to identify the problem? Also, I've heard you can clean the existing throttle body which may help. Should I try this first, and if it still doesn't help, then replace the throttle body?
Thanks!
EDIT: Also, I did some research prior to posting this, and people were saying that Aveo's doesn't have a serviceable throttle position sensor - that you have to replace the whole throttle body. Is that true even with a 2010 aveo? I'd rather replace or clean small parts first before spending $170 on a new throttle body if that doesn't help.