08 engine bogs down bad and won't accelerate when getting in to the gas. Have to ease and feel way through acceleration. Also gas mileage is down to under 20 mpg. Thoughts? :confused:

I assume you've been getting better gas mileage with the same driving pattern. The air-fuel ratio is off. Bogging down is from running too rich. Take it in to get it fixed. If you keep driving like that, you may be looking at a new catalytic converter in the near future.

Throttle body need cleaning? http://www.truckmodcentral.com/forums/images/smilies/dunno.gif

Starship's reply makes more sense though, cats may go out soon if not checked.

Hmm...Sounds like my car. AND im only averaging 19mpg with A LOT of freeway driving too. My car falls flat on its face when i try to take of fast. I feel like it accelerates better when im lighter on the gas pedal because the engine doesn't feel like its bogging down. Maybe its just the nature of this car :confused:

Could be a bad plug or wire too.

More than likely if the mixture was too rich or there were a problem with a plug wire you would get a check engine light. The front O2 sensor would pick up a rich condition and set a code or if the O2 sensor wasn't responding correctly a code would also be set. Misfiring plugs would also cause a check engine light. The OBD II electronics are designed to catch these types of problems.

Does this sag occur only when starting from a stop or anytime you drop the pedal to the floor no matter what speed you are going?

Does anything on the instrument panel light up when this happens?

Bill

Since OP didn't mention CEL, the best I could recommend was/is to take it in. Without any scanner data to comb through, I don't see how to proceed. Also, a problem like that can become very costly by the time CEL comes on.

Thanks for all the input. Yeah, no codes showing up and I have already checked the obvious things to include running a tank of gas with techron fuel cleaner. It does do it any time I get into the gas pedal, not just starting from a stop. It feels like a fuel air mixture problem to me, so even though it is showing no codes I will take it in and keep you posted as to what they say it is.

Take it right to the dealer. Emissions are automatically covered by Fed regulation. If you mess around, they may claim you did something.

Took it to the dealer. Catalytic converter needs to be replaced. Covered under warranty so all is well. Thanks everyone!

Hmm, that's not what I would've expected on a '08.:confused: Thanks for the update.

Took it to the dealer. Catalytic converter needs to be replaced. Covered under warranty so all is well. Thanks everyone!

Let us know how your car feels after they replace it. :)

A clogged Cat will cause an engine to bog under acceleration. Only know of 2 ways to check for this. One is with a Vaccum Gauge. The other was with a Laser Temp sensor. Reading the Inlet and Outlet Temps of the Converter.

What I'm wondering is the old chicken and egg problem. Given the relatively new car, I would've expected something else that caused the rich condition which in turn toasted the catalytic converter.

Ok, so here's the thing. It's supposedly the front one. (they say it has two, one just past the manifold and one in the exhaust line) I turned it in to them on May 26th and as of today, June 7th, there is not one available in the whole country! They say I can come and get it and drive at my own risk, but if it clogs the whole way I will be responsible for the exhaust replacement. I can find in stock after market ones for just over $500, but this is supposedly covered under warranty at no cost to me, except, I have now spent almost $400 on a rental car... UGH... Dealers... Come on... not a single cat for this 08 Malibu in the whole country?!? I love my Chevys, but dealers and their service departments....

Hmm, you are paying for the rental? I haven't looked over the warranty terms but shouldn't they provide you with a rental/loaner?

Hmm, you are paying for the rental? I haven't looked over the warranty terms but shouldn't they provide you with a rental/loaner?

Yeah, that is odd. Even when my old G6 was past the 3/36 and under the 5/100 when I took it in they gave me a free loaner.

I agree -- Are you under the 3/36 still? If so, it's pretty much unacceptable that they aren't giving you a loaner.

Believable, however. I've had the "oh, noone ever gives loaners, ever anymore. yeah that stopped in about 1954 i think, right? jim? 'Oh, yeah no i think it was 1957.' Oh, yeah i remember now. yeah, 1957 it was. But you can rent one yourself, i mean thats fine with us if you need to get around. (i speak) oh, yeah no that shuttle service is only at certain times of the year. this isn't one of them." You get the idea; oh, and they did have loaners. It was a misunderstanding.

I have never dealt with a "good dealership." I've dealt with about 8 different ones. I get so jealous when you all have your awesome stories!!! :-)

Anyways, if they are saying things like "sure go ahead, but we aren't liable if you do!" sirens and smoke clouds and angry horns would be going off in my head.
Don't touch the car until they sign that work is complete and call GM about a loaner. It's their policy and this is an EPA regulation that is at stake. They are telling you to run with a busted cat and then you're liable. grrr.

Best of luck to you, but this makes me nervous for you as well.

I wonder what happened in the first place.

Ok, going on 3 weeks, still no loaner, no rental car reimbursement, and GMAC SPAC case still has no identified part or delivery date. Looking at $600 in rental car now. I'm just over 40K miles, so not in the 3-36 any more, so emissions warranty covers part and labor, but not eligible they say for loaner or reimbursement even though I have bought 3 Chevys from them in 6 years...Anyone have some adivice on how to get GM to work with me on this since the dealer isn't?:mad:

This situation falls under "good will" on the part of the dealership which is inexplicably absent. According to http://www.epa.gov/oms/consumer/warr95fs.txt, your options include taking independent legal action, contacting EPA, contacing local or State consumer protection agency or office of the Attorney General. But, I'd first contact the GM customer service again and ask for your case to be escalated to the next level. What I'd be looking for is the authorization to use aftermarket, non-GM parts either by the current dealership or an independent repair shop.

EDIT: I guess I don't even know if you've already called the customer service. If not, call 800-222-1020 and then keep hitting "0" until you get a live person.

If you prefer, you can also e-mail Jared Duane through http://www.gminsidenews.com/forums/sendmessage.php?do=mailmember&u=49047 (if you are not a member of that forum yet, you'll need to sign up). He's apparently in GM Customer Service.

Personally... go pick up the car, take it right down to the local muffler shop and have them replace the cat, it's not hard to do. Then go hire yourself an attorney and see GM in court.

To me, it appears to be a case of bad apple dealership. It's possible that this particular dealership is in trouble with GM (charging unreasonable volume of warranty work for the number of cars sold, etc.). I hope the OP will give GM Customer Service a chance.

Well, GM Customer Service has agreed to let me "skip" a car payment as it has been almost 1 month to the day since I took it in to the dealership and even GM wasn't going to arrange a loaner for me. ($503) We'll see... I spent over $700 on rental...some is better than none I guess.

Picked up car this afternoon, and although it is better, the basic symptom is still there when starting from a stop or trying to accelerate from a low rpm gear. I have to feather the throttle to accelerate or really step on it to get to a lower gear and higher rpm. (over 2500 is best). Fuel mileage is terrible...15 at best... BUT, I can't even think about taking it back to that Dealership. I am thinking the same thing that one of the posters "Starship" mentioned...what is causing this in the first place...something has to be causing the air/fuel mixture to be wrong...before the front Cat... I can't believe they didn't check this before returning it to me... UGH! I have driven Chevys my whole life...but this is testing my loyalty to it's limits...

You've got no idea how sorry I am to hear of your continuing saga. Confirm that you have a 2008 2LT with I4/A6. They should have given you a work receipt with part numbers and such. Can you post its contents (don't need VIN or dealership name)? BTW, sometimes it runs a little rough at first if they've disconnected the battery (presets on your radio gone).

Be careful when they say skip a payment. Make sure that the principal was reduced from the outstanding balance. Usually when they offer skipping a payment it means that you just don't make this months payment, yet the balance isn't reduced and interest still accrues on the outstanding balance. Thus, all it does is give them additional interest.

If you still aren't happy with it, call GM Customer Svc back and tell them that you would like to take it to a different dealer.

They listed an L2300 Coverter, oxidation catalytic replace, 4108 W 1.30; 1 12618546 Monifold; core charge w; 1 22626930 Gasket; 1 12589453 Gasket; FC: 6023; PART# 12618546; COUNT: 1; CLAIM TYPE: ZREG

I have the 2.4L MFI DOHC HO ECOTEC, TRN: 4 SPD AUTO

Let me know your thoughts.

tim

Okay, I asked for the information because things just didn't mesh. So, L2300 is the labor and the parts are exhaust manifold and gaskets for the 2.4L ECOTEC (means you don't have a V6, I couldn't be sure). Assuming you're in the U.S., the 2.4L ECOTEC does NOT have front and rear catalytic converters. Unless they replaced the one underneath on the passenger side on their own dime, they didn't do the work they were supposed to do.:( Please get in touch with the GM customer service and ask for a way forward. Do remember that you should be beyond mad but this fiasco is on entirely on the dealership.

GM Customer service is aware now that the car is not fixed and that I WILL NOT take it back to the same dealership. I have an appointment set up for drop off and evaluation of the problem with another local dealer Wednesday next week.

GM says they are set to authorize the original dealer to reimburse me one months payment now...maybe next week. We'll see...

Interested to see what the real problem is and to have my smooth running Malibu back to full capacity...this has been a long time...

Thanks everyone for the feedback and advice. I will keep pluggin along and let you know what they say next week.

tim

Just because I do feel the torque and push when i add throttle off the line, I wanted to make sure that my solid feeling and satisfaction was not related to this.

I took a little 11PM spin to see what happened and recorded my MPG with my Scangauge. Remember I am 4spd 4cyl. About 20% city, 80% highway between 60 and 75, over 25 miles and I got 28MPG. Now i know thats a small sample distance but it was something I did just for this thread since my daily drive(if i drive a given day) falls under the "scary mpg" range but I feel this is to be expected Commuting into downtown Chicago at rush hour (~18MPG)

18MPG out of a 4-cyl? Holy dear god. I knew the Malibu was too heavy for the 2.4/4spd combo, but I didn't know it was that bad.

I really do miss my Cobalt SS... 240hp to the wheels and 35MPG on the highway.

GM Customer service is aware now that the car is not fixed and that I WILL NOT take it back to the same dealership. I have an appointment set up for drop off and evaluation of the problem with another local dealer Wednesday next week.

Jeez, what a mess. I'll be keeping my fingers are crossed.

18MPG out of a 4-cyl? Holy dear god. I knew the Malibu was too heavy for the 2.4/4spd combo, but I didn't know it was that bad.

I really do miss my Cobalt SS... 240hp to the wheels and 35MPG on the highway.

18MPG in bumper to bumper traffic. That is pretty good mileage IMO. It takes about 30 minutes to go 5.5 miles.

I felt like I was getting about 24-28MPG on the highway and I am -- That was just a test related to this thread to confirm. But yes, I would definitely get the 6speed since I would like something a bit higher on the highway. For city driving I get about 24MPG. My commute to work when I drive in is not city driving by any EPA definition.

18MPG in bumper to bumper traffic. That is pretty good mileage IMO. It takes about 30 minutes to go 5.5 miles.

I felt like I was getting about 24-28MPG on the highway and I am -- That was just a test related to this thread to confirm. But yes, I would definitely get the 6speed since I would like something a bit higher on the highway. For city driving I get about 24MPG. My commute to work when I drive in is not city driving by any EPA definition.

Had you considered a Hybrid? I mean a real Hybrid like a Prius. They are made for that 30MPH bumper to bumper crawl stuff b/c the engine stays off most of the time.