I have been having issues with my 09 G37X banging when you have to slow down suddenly and then give the car gas again. This happens at least twice a week. I've already had the TSB software update done in December, but the car still does the same thing. Most recently, I had to slam on the brakes for a truck that pulled out in front of me. The engine did it's revving thing again and then when I went to get back on the gas (as a huge truck was bearing down on me), the car would not accelerate while it was still revving. Scared the crap out of me
It's back at the dealership today, and I was wondering if anyone has had this problem and if so, what was the solution ? We bought the car new with no trade and a great interest rate, but unfortunately, we are still upside down or she would be on a used car lot somewhere. Until this whole thing started, this car was the nicest car I have ever had and I would have easily bought another one, but this is getting ridiculous. Is this a tranmission issue
Thanks in advance for any help you can offer, other than to make use of a can of gas and a match

 

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lol, good luck getting a straight answer to this thread. great title...just not if you want serious input.

 

Aren't you still under warranty? It sounds like you definitely were when the issue started occurring. It sounds like it'll be tough to exhibit the issue to the dealer, but you should be able to get it covered under your state's lemon law if it keeps happening. This is a strange issue, never heard of it.

In the meantime, safe drive prescribes that you NEVER put yourself in a situation where you have to use the power of the car to get yourself out of trouble.

Sorry to hear, good luck.

Oh, and are you sure you're upside down on the car? Even if you were on a 72-month loan, you should be closing in on half the value of the car. The car should not have depreciated that much. Regardless, even if you do try to sell it, you might have to answer for the possible issue with the car.

 

It was a leftover, I bought it in January of 2010 after my 07 Hyundai Santa Fe received $13,000 of damage from a rear end accident and she was only worth $17,000. I bought it before I even got my Hyundai back because I didn't want any parts of it after they cut the entire floor pan out of it while trying to straighten the thing out. I wanted all wheel drive, but didn't want another SUV. We had an 08 Vette at the time, so German was out of the question because of price.
I owe $31,600, KBB is $27,700. Yes, it is under warranty, but that doesn't make me feel any better. We have 23,000 miles on it.
Lastly, I was doing the speed limit, a car pulled out in front of me and a tractor trailer came over the hill behind me driving way too fast. I did not put myself in an unsafe position, the other morons who are doing everything but driving safely did.

 

Oh yeah, I understand there are situations where it's completely unavoidable.

OIC, you've only had it about a year...

So is the main problem that the car seems like it doesn't engage a gear? What do you exactly mean by banging?

 

If you have to slow down quickly and then give it gas again, it "clunks" (maybe that's a better descriptor) hard into gear. The first time it did it, I thought I hit something after slamming the brakes on to avoid the WV State mascot (Deer). The second time it did it, I was slowing down for a red light when it cycled to green. I was going about 30 when I stepped back on the gas, clunk, bang, whatever you want to call it. Third time, slowing for RR tracks, down to 25, back on the gas, bang (Hubby was driving it that time and said WTF was that?? I said see ????) Fourth time, just got onto the highway (55 mph). Car cuts me off, realizing that's his exit ahead. Slowed to maybe 35-40, back on the gas, bang. Last time and most recent was the one listed above. I don't know if it's tranny or the differential or what. I don't drive her hard, I'm not beating on a car that we paid that much for, she's not a rent-a-wreck, despite starting to resemble one. I was planning on keeping her until she was paid off, but she will more than likely go when her value is even with her payoff. She is spotless and meticulously maintained. We always get our money's worth out of our trades, but if she keeps this up, I'll take a small hit and kick her to the curb !

 

I had a similar problem with my last vehicle, which was a Ford Edge. It put me off automatics of any kind. I found myself using the gas and brake to manage the automatic tranny. When I wanted to pass, I'd have to give it gas "just so", to get it to change a gear. There were plenty of times I'd pull out to pass, not get a gear change, or get a gear "disengagement" with lots of revving, but no new gear. And sometimes the new gear would come in with a hard bang like what you're describing.

I chalk it up to the automatic trannies getting too complicated in the name of saving money or gas or something. All this "fly-by-wire", computer-controlled stuff gets in the way of my driving.

I'm either going to stick with manuals, or at least a double-clutch system like what a lot of high-end cars are using these days.

In the Edge, I tried to get the dealership to fix it, and they tried a few times. It would get better for a while, then I'd be back in a few months later with the same thing. They said there was an oil leak in the transmission. Then they said it was the computer, which was reset/reprogrammed. Then they said they'd take it out and look at it more closely. Never really got it solved.

Try driving another auto-equipped G and see if it's the same. I suspect it's just the nature of these transmissions....

 

Yeah I have a 6MT so I don't have any experience with the 7AT in this car. I do know that when I drive my wife's 535i, it has similar behavior but more prevalent at lower speeds. And I think that your "bang" is much more abrupt than what the 535i is doing.

Harsh downshift to 1st [Archive] - Sprinter-Forum

That link seems to detail almost exactly your issue. In it, someone recommends resetting the transmission learning. I'd give that a shot. I believe you can do it on your own by resetting the ECU.

 

Let us know what the dealer says. It's definitely not normal.

 

Wait this isn't normal? LOL I get the EXACT clunk when I brake harder than normal. My guess is the automatic tranny downshifting abruptly to a lower gear since we're decelerating really quickly. Just don't brake so abruptly and everything will be fine. But if this is a problem...let me know because I have the same issue. But I don't think it's anything serious :/

 

I don't know if this is a more subtle version of what everyone is talking about, but sometimes when I brake a bit harder than usual (meaning you'll feel a jerk when the car comes to 0 mph), there's a pretty noticeable CLUNK noise coming from the back of the car. Happens at least once a day. Doesn't seem to affect my braking or performance so I let it be.

 

tharbemiko beat me to the punch. Ditto.

 

I've experienced the same thing once in a while. It seems to occur when I'm slowing down and need to get back on the gas again relatively quickly. It is a very loud clunk and you can feel it as well.
It is almost like there is "sweet spot" in a certain gear and engine rpm when decelerating and you hit the gas that it occurs.

 

Okay, my service advisor said that despite having the TSB done back in December to reprogram the ECU software, it was still showing the old software. They reloaded the new ECU program and feel as though this will be the fix. ("Groundhog Day" movie flashback, I believe they said this the last time )
Hubby took her in today and on the drive home, he said that the 2>1 downshift is a little harder, but that it didn't do any of the things it was doing before. He also noticed that when slowing from 60mph to say...35, the revving is quicker and allows you to get back on the gas without the lag and without the horrible bang. Hopefully this will be the fix I needed. I love this car, but having this kind of issue sucks the life out of what I love about her. Keep your fingers crossed for me and Bella, we'll keep you posted.