Sign In Join 



Chevrolet Cobalt

2164 messages,  Last post on Nov 05, 2009 at 5:08 PM

You are in the Chevrolet Cobalt Forum. Your Hosts are pat & karens

What is this discussion about? Chevrolet Cobalt, Coupe, Sedan


Messages Page 208 of 217
1
...
205
206
207
208
209
210
211
...
217
Prev
Next
Last
Go To Msg #
Search This Discussion

#2070 of 2164
Re: Cruise Control [micweb] by tsjay
Nov 26, 2008 (11:12 am)
Reply

Replying to: micweb (Nov 26, 2008 9:58 am)

Thanks, micweb. I was wondering if those prices were in line.
 
So, I guess I have to decide just how badly I really want cruise. Right now, I don't think I want it $400 worth, but I could change my mind.
 
I would want it to be just like "factory," if I got it.
 
Tom
#2071 of 2164
Consumer Reports by dispencer2
Nov 30, 2008 (8:00 pm)
Reply
The current issue has an article on cars their readers won't purchase again. 46% of them won't purchase another Cobalt sedan. I can't figure out what is wrong with the Cobalt. I've rented a lot of compacts and find that most of them are pretty much alike. Some have fancier interiors but I have had nothing but good luck with my 09 LT1 coupe. I understand that the 05's and 06's had small problems -squeaks, small warranty things and most of the bugs are gone now. Of course everybody loves their Japanese cars -typical CR readership.
#2072 of 2164
by steve333
Nov 30, 2008 (10:00 pm)
Reply
Whenever I bring my '06 Cobalt LT Sedan to the dealer for an oil change they always set my tires to 35psi even though the doorjam says they should be 30psi.
Same thing happens at Discount Tire. I went for a rotation and they set the tires to 35psi and said it was better at that level.
I'm confused-what psi do you guys keep your 'Balt at?
 
Also my car is riding horribly. It almost feels like my shocks/struts have no fluid in them, its that rough over bumps. Also, now my car doesnt even handle properly-it feels tippy around turns where it used to at least handle well (kinda made up for the rough ride!). Also, on the Freeway here in SD the car has terrible back and forth action on the grooved freeways (brand new Michelins did not help at all).
I am very dissapointed in the way the car is riding. Its really the only thing that bothers me about the car, but, hey, thats a pretty big issue.
#2073 of 2164
Re: [steve333] by imidazol97
Dec 01, 2008 (6:50 am)
Reply

Replying to: steve333 (Nov 30, 2008 10:00 pm)

Get a quality tire gauge of our own. Set your tires to a pressure you want when stone cold in your driveway after sitting outside all night e.g. Remember the ambient temperature changes the pressure about 1 pound per 10 degrees (F) of temperature rise of drop.
 
I often run a couple or three pounds above the recommended. I have Michelin tires on my cars but they're not Cobalt.
 
As for being sensitive to wiggle on grooved roads, that's most likely a function of the alignment. It should be set to perfect--especially for the rear. This is one time it might be worth a dealer visit for the alignment over the local tire store, depending on the experience and attitude of the guy on the alignment rack.
#2074 of 2164
Re: [imidazol97] by steve333
Dec 01, 2008 (7:38 am)
Reply

Replying to: imidazol97 (Dec 01, 2008 6:50 am)

I'm going to try them on 32psi then. Its about 55 degrees here in the AM so that shouldnt affect the pressure that much. So, 2 pounds over the doorjam amount and I'll see how it goes.
I had a alignment from the dealer and tires balanced, didnt seem to help much. I was told that the tire treads get caught in the grooves in the freeway, more with some tires than most, but who knows if they were just storying me.
#2075 of 2164
Rain Groove Reaction Varies with Tires by micweb
Dec 01, 2008 (9:05 am)
Reply
My '09 Cobalt has no problems with NorCal rain grooves, my '09 Focus does. Go figure. The last 10 or so cars I've had with stock or aftermarket tires have had no rain groove problems. If it bothers you a lot, try switching to a tire with a much different tread design. Falken ZE512's, Kumho KH16's, Bridgestone 960's (mine were the last gen 950's) are all tires I've had good experience with.
 
As for your ride being harsh, go test drive a new Cobalt and see if it is better or the same. Ride is very subjective, and also depends on the roads. The Cobalt has a nice ride imho and by most 3rd party accounts (including the recent test on this Edmunds site). While there could be a shot shock or strut on your car, it's unlikely these days. Bounce each corner (get out of the car and shove each corner of the car up and down) and see if you notice anything out of balance between corners.
 
If you need to replace a strut or shock, a replacement Chevy part shouldn't cost that much. Generally I Google to find an online dealer that discounts parts and use my VIN (i.d. from my car) to order from them then have it installed at the lowest cost shop in my area. Tire Rack has a good list of recommended installers for shocks and tires.
 
35 psi is what I run all my cars at. It used to seem high, I got used to it, it's better handling, better tire wear, better mileage, and more margin for error if you lose some air. But get a good tire pressure gauge, go to a Napa parts store and get their "pencil" style gauge which is cheap and accurate. Don't fall for the "digital readout" gimmicks. CR gave the Napa gauge good marks for accuracy and repeatability.
#2076 of 2164
I vote for the factory recommended tire presssure by tsjay
Dec 01, 2008 (9:25 am)
Reply
I see no reason NOT to run the recommended tire pressure, especially with the original equipment tires. Overinflation will make the car ride rough, not handle as well, and will cause the tires to wear out in the middle. Underinflation will accelerate the wear on the inner and outer edges of the tires.
 
I go with the recommended 30 psi, and I am happy with the ride and handling. Time will tell as far as how evenly the tires will wear.
 
Tom
#2077 of 2164
Re: [steve333] by cmhj2000
Dec 01, 2008 (11:03 am)
Reply

Replying to: steve333 (Nov 30, 2008 10:00 pm)

Run my fronts around 36 with rears around 32 on both of my LTs.
 
For years I've always ran a bit higher pressure on my front tires, if front wheel drive. Have seen a more even wear pattern on several vehicles.
#2078 of 2164
For GearHeads Only - Technical Explanation of 2.2L Engine by micweb
Jan 06, 2009 (9:49 am)
Reply
I don't know why GM makes this information so hard to find, but here is a fact sheet from the GM public relations department on some of the technology incorporated into the 2.2L engine that powers our Cobalts. It's fun to learn that, yes, GM DOES have a great engineering side to its operations, and isn't all about cutting costs:
 
http://media.gm.com/us/powertrain/en/product_services/2009/Stories/Ecotec/09_LAP- _n.doc
 
alternately, go to media.gm.com and search for
 
2009 Ecotec 2.2L
 
Just cut and paste this string and drop it in their search box, and after the initial search comes back, check the "Powertrains" subheading in the left column to narrow the search. Also be sure to check the "search for all words" button under the search box, and after you follow those two steps, item 5 should be the link to the article. Like I said, GM's public relations department doesn't make a gearhead's life any easier, but the article is worth reading. Here are some interesting exercerpts:
 
"The [2009] Ecotec 2.2L starts with a refined engine block, introduced for 2006 with the Ecotec 2.4L I-4 VVT (RPO LE5). The Gen II block was developed with data acquired in racing programs and the latest math-based tools. Both the bore walls and bulkheads, or the structural elements that support the crank bearings, have been strengthened, with only a minimal weight increase (approximately 2.5 pounds). The coolant jackets have been expanded, allowing more precise bore roundness and improving the block’s ability to dissipate heat. Coolant capacity increases approximately .5 liter."
 
"The [2009] Ecotec 2.2L VVT I-4 also benefits from cylinder head refinements introduced on the 2.4L VVT. The exhaust ports have been enlarged slightly to expel exhaust gas more efficiently."
 
The 2009 Ecotec 2.2 used in the Cobalt apparently also has improved materials for the valve seats and certain other engine parts to allow it to use E85 fuels in certain applications. Although only the HHR version is certified for E85 use, APPARENTLY all 2.2s have the durability upgrades, but only the HHR version has the revised fuel injectors that allow higher volumes of fuel delivery which is required with the lower-energy E85 fuel (so don't go trying to run E85 in your Cobalt! - it's apparently very corrosive stuff). The ECM in the HHR reprograms the engine "on the fly" based on feedback from the O2 sensors and other engine sensors to adapt to ANY mix of E85 - which is great since the first and last tanks of E85 are going to have a different percentage of alcohol until the gasoline is all flushed out when you start using E85 and until the E85 is all flushed out when you switch back to gas. (It's not clear that non-Flex Fuel vehicles, like our 2009 Cobalts, also have the same software programming, but given that other portions of the article stress GM's desire to have uniform manufacturing as much as possible across the 2.2 line, and given the fact that many states mandate E10 - 10% ethanol - for ALL vehicles, very likely the Ecotec does have this "fine tuning on the fly" ability - GM brags about the much higher engine sample rate used in ALL the 2.2 versions, for example.)
 
The VVT or variable valve timing system used in the Ecotec isn't a primitive system - it arrives to the Cobalt with completely variable valve timing on BOTH intake and exhaust valves, and the variability is NOT just linked to RPM - it's also linked to driving loads, and throttle usage. I think this is what Toyota offers on its VVTi or "variable valve timing with intelligence" system. So if you get on the gas pedal while at low rpm, the engine reprograms the camshaft timing from optimal fuel economy mode to optimal performance mode RIGHT AWAY not 2,000 rpm later.
 
Of somewhat more technical interest (to the gearhead, of course) is that fact that GM seems to operate the 2.2 in mild "Atkinson" cycle mode (if I got that right):
 
"The cam phaser is timed to hold the intake valve open a short time longer than a normal engine, allowing a reverse flow into the intake manifold. This reduces the effective compression ratio, allowing the expansion ratio to increase while retaining normal combustion pressures. [That's the "Atkinson" effect vs. the traditional "Otto" 4 stroke cycle.] Efficiency is gained because the high expansion ratio delivers a longer power stroke and reduces the heat wasted in the exhaust. This increase in efficiency comes at the expense of some power from the lower effective compression ratio, but that can be compensated for by the overall higher mechanical compression ratio. [As we know, the Ecotec 2.2 has 155 hp and 150 lb-ft of torque this year, up considerably from last year, so apparently the performance has only improved, not been hurt.]"
 
If you download the h.p./torque chart for the 2.2 (a different document from the link above), you'll see that at higher rpm the torque doesn't fall off, it stays strong and h.p. keeps increasing. The Cobalt cries out for a 5 speed! (And the "old," "non-fuel economy maximizng" ECM software on the automatics - the newly programmed automatics don't like to downshift as easily as before.)
#2079 of 2164
I cant hook my bluetooth capable phone up to my car by iluvnanny
Jan 07, 2009 (5:45 pm)
Reply
I already posted this in another forum and reposting is probably poor form but oh well i really need an answer to this question. all the websites and forums say the 2009 cobalts are bluetooth capable but mine refuses to let me hook it up. the gm website says to push the call button and say 'blue tooth' but that isnt working. any ideas?

Messages Page 208 of 217
1
...
205
206
207
208
209
210
211
...
217
Prev
Next
Last
Go To Msg #
Search This Discussion
To POST a message, please Sign In.

New? Join Now!

Forum Tools

Please sign in.
Email Address:

Password:

Forgot Password?

Search Forums

Enter Keyword(s)

Advanced Search

Browse by Vehicle



View All Vehicles
Advertisement
Ask the Community
See What People Are Asking

Browse by Board

Browse by Topic


View All Topics
Advertisement