Hi all, I have a quick question.
I just bought a 2007 Aveo brand new - it has 299 miles on it. It's been driving pretty well. But this week in the LA area it has been really hot, and while driving down the PCH in stop and go traffic for about 10 or 15 miles (traffic was moving really slowly all the way through) at 3:30 to 4 PM, I noticed that the transmission and engine were getting really sluggish. When I drove up Malibu Canyon, the temperature soared to at least 100 degrees, and when I got on the 101 I was having a hard time getting it up to speed - it seemed to not want to shift into fourth and I had to floor it. It shifted down, revved briefly to 4000rpm, then finally at about 60mph shifted up into the correct gear. Once it was up to speed it seemed fine. It also was a little sluggish getting up to speed from a dead stop, I had to really push the gas to get it to move.
After I had parked it for a while, I took it back out and it had no problems (it went up to 65 on the 101 with the kind of pickup and shift behavior I was expecting), although I noticed that as I switched the AC on and off the power drain was noticable.
Is this normal behavior for an Aveo in very hot weather? I called the dealer and he mentioned that his truck was also acting a little strange and advised me to just keep an eye on it but he thought it was normal, and I read a website that says these GM engines can lose 20% of their power in excessively hot weather. I am wondering if the transmission got hot and coupled with a loss in power from the engine caused by the weather and the AC that things were kind of flaky.
Thanks, hope this is the right area, I wasn't sure if it should be engine or transmission...
Also, are these engines (I know this isn't the engine section) designed for high RPM operation at 4 to 5 thousand RPM? My old ford mustang got really flaky at over 3000.
(thanks johnnyc over at totalfark for directing me to this forum)
Hot weather sluggishness
Moderators: daewoomofo, Moderators Group
No problem man.
As to the problem you're talking about, well... I'm not sure about all of it, but I know that when I've gotten a lot of hot air into my short-ram intake, it has dropped the power considerably. I eventually built a heat shield and it now pulls more cool air from the wheel well rather than the hot engine bay. In any case, it's possible that has something to do with your power loss, but it could be something else as well. My Lanos rarely has problems getting up to speed, but I've made a few modifications to help with that and I drive a stick, so I have a little more control over the gear I happen to be in.
Someone else will probably have some other ideas as well.
As to the problem you're talking about, well... I'm not sure about all of it, but I know that when I've gotten a lot of hot air into my short-ram intake, it has dropped the power considerably. I eventually built a heat shield and it now pulls more cool air from the wheel well rather than the hot engine bay. In any case, it's possible that has something to do with your power loss, but it could be something else as well. My Lanos rarely has problems getting up to speed, but I've made a few modifications to help with that and I drive a stick, so I have a little more control over the gear I happen to be in.
Someone else will probably have some other ideas as well.
Thanks.
I was reading up, and it turns out that excessive stop-and-go traffic in hot weather can overheat an automatic transmission, and I think that *may* be what happened. I have no way of proving it, however. I think I'll just keep an eye on it and have then change the fluid sooner than they usually would if this doesn't happen anymore.
15 miles of stop and go traffic in 90 to 100 degree weather certainly qualifies.
Nothing I could do about it, though, except maybe take the 405, and that would have been *worse*.
I was reading up, and it turns out that excessive stop-and-go traffic in hot weather can overheat an automatic transmission, and I think that *may* be what happened. I have no way of proving it, however. I think I'll just keep an eye on it and have then change the fluid sooner than they usually would if this doesn't happen anymore.
15 miles of stop and go traffic in 90 to 100 degree weather certainly qualifies.
Nothing I could do about it, though, except maybe take the 405, and that would have been *worse*.
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BosnianLanos
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I doubt your transmission overheated. If it was stop and go traffic, you weren't really putting too much stress on the transmission, so it had no reason to overheat. Besides, the transmission has a built in cooler that is part of your radiator, so the temps could only have gotten to the temperature of the engine coolant. Which is just fine for the transmission. If you were towing it would've been a different story.
I can honestly say I've been experiencing the same thing. I have a Lanos 5 spd. that is just plain slow in hot weather. I put in a full CAI, with heat wrap, but it only helped marginally. When the engine reaches normal operating temperature the power drop is HIGHLY noticeable. It is very sluggish unless I rev pretty high. With AC it is even worse. I think the power drop is like 15%. So, if you simply think about it, the power loss makes sense. For every 10 degrees hotter, you lose 1% of your power. Considering a normal intake in hot traffic reaches about 80 C or about 176 F (As seen in the "INTAKE TEMP" gauge of an Evolution I drove frequently) that means you are about 100 degrees over your desired temperature of about 75 degrees where the car makes its "stated" power. Couple that with the 15% from the AC, and you're looking at a 25 HP loss. On a car that makes about 90 HP to the wheels, that is CONSIDERABLE and will be the cause for the sluggishness. Realistically, this won't do any harm to your car, but it will annoy you, and potentially make it unsafe while merging, passing, etc. So my recommendation to you is to pull the OEM intake and resonator and install a CAI. It will help, and will cool down a lot quicker after open-road driving.
And yes, as soon as night drops and the temps fall off, the car is back to its old self. And I'm in Gainesville. The temps today reached 93 with 98% humidity. It is hell for cars.
I can honestly say I've been experiencing the same thing. I have a Lanos 5 spd. that is just plain slow in hot weather. I put in a full CAI, with heat wrap, but it only helped marginally. When the engine reaches normal operating temperature the power drop is HIGHLY noticeable. It is very sluggish unless I rev pretty high. With AC it is even worse. I think the power drop is like 15%. So, if you simply think about it, the power loss makes sense. For every 10 degrees hotter, you lose 1% of your power. Considering a normal intake in hot traffic reaches about 80 C or about 176 F (As seen in the "INTAKE TEMP" gauge of an Evolution I drove frequently) that means you are about 100 degrees over your desired temperature of about 75 degrees where the car makes its "stated" power. Couple that with the 15% from the AC, and you're looking at a 25 HP loss. On a car that makes about 90 HP to the wheels, that is CONSIDERABLE and will be the cause for the sluggishness. Realistically, this won't do any harm to your car, but it will annoy you, and potentially make it unsafe while merging, passing, etc. So my recommendation to you is to pull the OEM intake and resonator and install a CAI. It will help, and will cool down a lot quicker after open-road driving.
And yes, as soon as night drops and the temps fall off, the car is back to its old self. And I'm in Gainesville. The temps today reached 93 with 98% humidity. It is hell for cars.
Thanks.
As long as I know what it is I can deal with it - I used to have a Geo Metro so I am no stranger to dealing with underpowered cars. This one is actually not so bad as far as power goes, but I was worried that there was something wrong with it. As long as it's just something that's normal I can work around it. Maybe even leaving the AC off and rolling down the windows will help in that circumstance (I have the sunroof, lucky me.)
I'm kind of OCD when it comes to things going on with cars (especially a brand new one like this) that I don't understand, and I will relentlessly pursue it until I know what's going on so I can work with it. Thanks for the answer, I appreciate it. I just don't trust it yet, my Aveo and I don't have the kind of rapport my old '89 mustang and I had (I didn't trust it, it was too old, but I knew exactly why and what to do if something went wrong) It'll be a few thousand miles before I start to relax and trust it.
For example, I got really mad at my seatbelt today until I figured out that you had to pull it out gently - if you pull it hard it locks up.
As long as I know what it is I can deal with it - I used to have a Geo Metro so I am no stranger to dealing with underpowered cars. This one is actually not so bad as far as power goes, but I was worried that there was something wrong with it. As long as it's just something that's normal I can work around it. Maybe even leaving the AC off and rolling down the windows will help in that circumstance (I have the sunroof, lucky me.)
I'm kind of OCD when it comes to things going on with cars (especially a brand new one like this) that I don't understand, and I will relentlessly pursue it until I know what's going on so I can work with it. Thanks for the answer, I appreciate it. I just don't trust it yet, my Aveo and I don't have the kind of rapport my old '89 mustang and I had (I didn't trust it, it was too old, but I knew exactly why and what to do if something went wrong) It'll be a few thousand miles before I start to relax and trust it.
For example, I got really mad at my seatbelt today until I figured out that you had to pull it out gently - if you pull it hard it locks up.