I purchased a 08 GT 3 weeks ago. Breaking it in by the book w/ avg speed under 30 mph, being kind to the car because I intend to keep it for a long while. At around 1080 miles the transmission takes about a 4-count to go into gear from park and revs wildly at the shifts. I put it in the shop and they re-flashed the computer but no improvement. They have never seen this before without codes being thrown. Anyone heard of this or am I just lucky? Thanx - Markus

I've had that problem in other cars. I can't remember if was the torque convertor or a line pressure problem. Maybe a sticky solenoid...?

I'd recommend checking your fluid level if you have the ability.

I'm surprised the dealership gave you the car back without doing more than checking for codes and reflashing the computer.

They haven't given me the car back yet. I won't take it back unless it is in prime running condition. I am also charged with buying 3 dressed to the nines Denali or Suburbans for our company to offset some taxes. Mine broke down in College Station TX this weekend while hauling my vintage formula car to Texas World Speedway for the races. It was one week back from the shop as well. My family only buys GM (8 since 03) and I'm feeling a bit stung at the moment. This is the same transmission model number that is in our Vette and that one has taken it's share of constant abuse. I haven't even broken the tires loose in the G8 yet except when I hit RR tracks. Maybe that is the problem.....I just read a few threads, It seems I'm not alone. May have to stray from the brand as the SUV's have the same tranny. That will be a shame.-Markus

Oh, okay that makes sense. It sounded like you got the car back.

I'd have them make sure to check the trans fluid level though. You'd be surprised at the stuff techs will skip over. And with the trans not having a traditional dipstick, most of the time you are going to assume it's fine.

You can remind them that they have a tech support line they can call. No one likes to call because you get paid an hour diagnostic and you'll be on the phone for 2 hours, meanwhile you could have gotten paid for 6 hours of work.

Thanks, sorry for the vent. All my cars are screwin with me except the old ones that I work on. Driving thru TX knowing the fuel pump was bad when they said it wasn't got me. I'll have to trust these guys to fix it right. This car is worth it. Never had a new car visit the shop. I'll call 'em in the morning when I'm done with my period.

I understand man. I've heard the crap enough times that I get pissy too.

If it makes you feel any better, I spent $425 getting the motor for my lift rewound, took them 3 weeks to do it. I got it back, works for 2 days, starts blowing a fuse. Take it back, they take 3 weeks to warranty the thing, meanwhile I'm working on the floor. Get it back, works for 1 day, starts doing the same crap. Now I've got a car stuck on the lift mid-way up.

I'm using toilet paper rolls for tampons at this point.

CHECK YOUR FLUID LEVEL! Many have been down 3-4 quarts from the factory! :wink2:

That is similar to what happened to me. When in sport mode i would drive and the RPMs would shoot to 4-5K and stick there. It felt like an ECM issue, but I'm no tech. Mine prob went away on its own after having occurred a few times. Techs told me the computers sometimes act glitchy when 'learning' your driver preferences. Seemed like a BS answer to me.

Thanks guys. Is there any shop manuals availiable for this car? I've got them on the LS's but I would like to own a range of knowledge on the G8. It is my favorite at the moment. Roomy, handles great, and enough HP for thrills. Feels like my kid is out of town.

Here is what the fix was:
1036 FAULTY TRANS FLUID PRESSURE SWITCH AND/OR SOLENOID PERFORMED
DIAGNOSTIC SYSTEMS CHECKS, FOUND DTC PO878 - TRANS FLUID PRESSURE
SWITCH 4 CIRCUIT HIGH VOLTAGE. PERFORMED TRANSMISSION OUTPUT AND INPUT TESTS. REMOVED THE TRANSMISSION VALVE BODY TO REPLACE THE TRANSMISSION SOLONOID ASSEMBLY. PROGRAMMED THE TCM. PERFORMED TRANSMISSION DRIVE CYCLES.

I picked the car up this afternoon. The car shifts better than it did before it crapped out. I might be hearing a slight rattle. Will test. Hopefully all is well. I love this car. Will buy there again. Whew!

I purchased a 08 GT 3 weeks ago. Breaking it in by the book w/ avg speed under 30 mph, being kind to the car because I intend to keep it for a long while. At around 1080 miles the transmission takes about a 4-count to go into gear from park and revs wildly at the shifts. I put it in the shop and they re-flashed the computer but no improvement. They have never seen this before without codes being thrown. Anyone heard of this or am I just lucky? Thanx - Markus

My 08 G8 GT takes a few seconds to go into reverse or drive, but only if I switch it into gear immediately after starting it. By immediately, I mean while the DIC says it is going through a self test. I doubt the two systems are related, or are they? In any case, it is the best way I can describe to you how fast you have to be to see the delay. Otherwise, if the car has been running for 10 to 15 seconds, there is not much of a delay other than what you would expect.

That is similar to what happened to me. When in sport mode i would drive and the RPMs would shoot to 4-5K and stick there. It felt like an ECM issue, but I'm no tech. Mine prob went away on its own after having occurred a few times. Techs told me the computers sometimes act glitchy when 'learning' your driver preferences. Seemed like a BS answer to me.

I have found that if I hold the gas pedal to the floor from a stop and go up to about 45 or 50 MPH and then quickly let off the gas, the trans will hold that gear for 4 or 5 seconds. That is the only time I have seen this issue, but I wonder if it is not an issue. What if it is supposed to do this when you are doing some spirited driving because it expects you to stomp down again? The gears don't hold any other time than when I really push it.

I had the same problem with about 500 miles on the car. I would leave from a stop and the trans would slip and the engine would rev between 1st and second and sometimes from second to third. I was sure I had a bad trans. I returned to the dealer, he noticed the delay when shifting the trans from park to reverse, but when I took it out with him it wouldn't slip.

He told me that when breaking in the car and following the break-in procedures the trans is learning your drivng habits. The first few thousand miles the trans gets confused sometimes and will mis-shift, seem like its slipping etc. Also these new 6l80E trans units are strange, and they do very strange things when new that even the GM engineers can't explain

I didn't buy the explanation, but figured it was under warranty, so why not just drive it, if it breaks its not my problem.

5000 miles later all my problems have gone away.

Go figure.

Man ive seen some bad tranny's walking the streets before.. lmao JKJK!

Back on topic now..

I'd recommend checking your fluid level if you have the ability.

I'm surprised the dealership gave you the car back without doing more than checking for codes and reflashing the computer.

I bet they did not check this. Many owners her ehave found they were shorted fluid by the factory, me being one. There is no dip stick and this must be done at the dealer. Bet your short by 3 - 5 quarts. Its an 11.4 quart system.

--Mike

That is similar to what happened to me. When in sport mode i would drive and the RPMs would shoot to 4-5K and stick there. It felt like an ECM issue, but I'm no tech. Mine prob went away on its own after having occurred a few times. Techs told me the computers sometimes act glitchy when 'learning' your driver preferences. Seemed like a BS answer to me.

I had this happen too. It stuck at WOT for about 5 seconds after passing a car on the expressway. Scared the crap out of me, thought my throttle was stuck.

--Mike

If my car stuck at WOT for a few extra seconds there would be dead people everywhere I looked.

haha thats awesome ^