OT Automotive Question

I realize this is off topic, but lots more traffic here.

I just bought my daughter an 08 Impala. It was on a 'for sale by owner' lot, but come to find out it came from a car flipper who buys them and fixes them enough to turn them.

Anyway, it has 2 problems, and so far the seller is working with me to get it dependable.

First problem, the transmission. He said they rerplaced the transmission and it is under warranty. I have not understood if it was rebuilt or used.

What it does, if stopped idling in gear for a few seconds, as in sitting through a red light, when taking off it slips, feels like the engine free revs for a second, then bangs hard and takes off. It doesn't do it every time, but seems the longer it is stopped the worse it is. It also shifts hard from 1st to 2nd, especially if you are getting up to speed quickly.

They are blaming it on programing and needing to learn. There is no fault code showing on the dash. I took it back for the 2nd time and they are going to look into it some more today. Anything I can suggest? They seem to somewhat know what they are doing, but this may be a little out of their league.

The other problem, it won't pass emissions. No check engine light, but the evap, oxygen sensor, oxygen sensor heater, all say 'not ready'. I drove it about 50 miles before the inspection, they said drive it more, I put a total of 113 miles and it still says the same. Any idea why?

Thanks!

Sounds to me more than a need to learn issue. Sorry I can't help with specifics, but those are a pretty darn reliable car..our kids had 2 over the years with over 200k trouble free miles

Ben

More Ethanol in the tank might get you past emissons check.

The transmission pump is failing -you have low oil pressure and when you rev the engine up it finally builds enough pressure to engage and you get the hard shift.

Does the check engine light come on when you first turn the key on (without starting it)? Sounds like it's been unhooked or (worse) burned out. Driving it won't fix it. Not knowing its history and buying it from a flipper - I wouldn't touch that car with 10-foot pole.

That's what I'm thinking, low pressure.

Yes the check engine light comes on before starting.

I was leery of it too, but after spending weeks chasing down total junk that was within the $5000 range, this was far and above anything else I had looked at!

The price of used cars is beyond ridiculous now!

What part of the emissions test is it failing? The engine's piston rings and cylinder bores could be worn out and burning enough oil to fail the hydrocarbon maximum limit. With two major problems I would return the car for a refund. Does your state have a lemon law?

I believe that transmission is in failure mode.

I replaced the battery in my 2013 Silverado a month before my inspection was due. I had only driven it ten miles before taking it to the inspection station. The tech said the code readers showed not ready on the emissions. I had to drive it 150 miles and then bring it back so they could get readings on the emissions.

Butch

The emissions issue is because the codes were cleared and the computer has not recorded the drive cycle it is looking for yet.

Do a web search for "your car" emissions drive cycle. You should be able to find what conditions are required for the sensors to ready themselves. Usually it is a mix of city and highway driving along with a certain number of temperature cycles. The idea is to give the system a chance to set any relevant codes and keep you from resetting them directly before the emissions inspection.

Daughter had an 07 Grand AM with the codes not ready problem. The recommended drive cycle didn't work. After three weekly trips to the inspection station getting failed each time they gave her a waiver. It took 6 months for her's to be ready and clear.

Howdy, new member, retired auto tech with a ton of GM experience, ended my career at a Chevy dealer in Rochester NY, ASE master tech blah blah
Sorry to say transmission sounds junk. Put their tech in the seat and duplicate the condition, or extend the warranty on the trans, but it's way more than an oil pump. 4 speed, right?
"Not ready" is what they call the emission monitors. These cars now self test their emission systems. After the codes are cleared, or the battery disconnected, all these self tests are wiped. Basically there are 8 subsytems tested. Each individual test has its' own parameters. For instance your evap test will never run if ambient temps are under 40f, if your fuel tank is not between 15-85% full, and you're standing on your left foot under a full moon. Oxygen sensor heaters requir a cold start. Catalyst tests require 230 coolant temp. So it can take a while to set them. In NY, if your car passes safety but fails for monitors, you're given a 10 day extension. Usually 3-4 days of normal commute will run them, and you only need 7 of 8, so the evap won't matter.

I don't know about your state, but in Ca. the seller is responsible to get it to pass emissions. sometimes it does take a lot of miles to reset everything. If you are at 113 miles you should be close. Stan

Thanks Pat80flh, everything you said makes sense!

It has only had 1 cold start, so I'll let it get cold before starting it a few times.

I suspect it has a 195 thermostat, is that the correct one? The temp runs consistently just a needle
width below the half way mark, whatever that is. I remember they said they replaced the thermostat,
which sounds scary!

The gas tank started out at 1/2 and was down to 1/8 after driving it around. Think I'll almost fill it
and see if that will clear the evap.

Got good news from the seller, if he's telling the truth, he said the trans was 3 quarts low! The girl
(yes, a girl, probably still a teen, and I would not want to scrap with her!) didn't finish filling it
after installing it. We'll see...

OK, so the tranny is 'under warranty', whatever that means. It needs to be fixed, and it's on the seller to make that happen. If he can't do it, you should get a full refund. Note that it's about four grand to rebuild that transmission, including the labor to R&R it.

I don't know about the transmission but I do have a chevrolet. Usually when the check engine light comes on it's because I have a vacuum leak somewhere. Early last year I had a crummy mechanic work on the AC and ever since the check engine light has come of frequently. Then about a month ago I see a vacuum line fall out from under the dash so I know he disconnected something that is messing with the engine.

I suspect it has a 195 thermostat, is that the correct one? The temp runs consistently just a needle
width below the half way mark, whatever that is. I remember they said they replaced the thermostat,
which sounds scary!

Yep 195, this is where a scan tool comes in handy, because the computer will not run many of the monitors unless the engine reaches full operating temps. Halfway sounds right.
Fill the tank to about 3/4, evap monitor won't run when tank is full