2011 Genesis lurches / jerks when accelerating

[PennyCat]

Hello! My 2011 Genesis sedan with automatic transmission lurches or jerks when accelerating, most noticeably around 50 mph and maybe 70 mph. Mechanic said he replicated the problem, wasn't getting any codes and thought it might be the transmission. Guy at the transmission shop said the problem didn't happen when he drove it and software / diagnostics showed no problem with transmission. Checking here to see if anyone has any experience with or advice about this issue.

 

[DaleNet]

Did this just start or has this been happening for a while?

 

[PennyCat]

Did this just start or has this been happening for a while?

It's been happening intermittently for about two weeks.

 

[DaleNet]

Have you gotten gas since it started? If you are not getting any codes, you might try running a tank of premium fuel from a good supplier and add a bottle of fuel injector cleaner to the tank. You may have a dirty injector.

 

[PennyCat]

Thanks for the suggestion. I will check that out.

 

[mikec]

One way to help isolate the issue is to put the transmission into the manual shift aka "sport" mode. Get to 50 mph, then put the transmission into the manual mode. Note what gear it is in; it should be the highest gear. Now try to accelerate. Unless you push the throttle pedal far enough to activate the "kickdown switch" the transmission should not change gears. If the acceleration is smooth (but probably slower than you'd like thanks to the transmission not downshifting) you have isolated the issue to the transmission. Repeat the test from 70 mph. If the acceleration is smooth at both speeds I would concentrate on the transmission. Dirty solenoids inside the transmission cause all sorts of shifting issues and may not be detected by the computer.

You can also accelerate to 50 or 70 mph, put the transmission into manual/sport mode again, and try to accelerate. As you press the throttle pedal, manually downshift 1 gear. Then repeat the test downshifting 2 gears. You may be able to isolate "the problem happens during the 6th to 4th gear downshift" which is good info to the mechanics.

mike c.

 

[pete268]

I've been having this issue with my 2013 R-spec. It started out as these sporadic lurches then it evolved to where it feels like it is riding in too high of a gear and acceleration from a stop is very poor. As it gets hotter out the lurching between gears is worse.

I tried it in manual and it does the same thing. It does it at low end speeds. I kicked it up to 120 and it did it in high gears at high speed. It is definitely worse when it is hot out.

My car is still under the 10 yr/100k warranty for transmission, but the dealer is terrible. It takes 6 weeks for an appointment and then they reprogram and it does nothing.

 

[PennyCat]

Thanks for the idea, @mikec I will try that.

Interestingly, I started noticing the problem recently which coincides with hotter weather. I hope you're able to get it fixed.

 

[Phantom520]

I just replaced the 8 speed transmission in my 2012 5.0 r spec. There are numerous technical service bulletins on this transmission. Lots of write-ups on this forum also. Mine was shifting hard from 3rd to 4th gear and slipping while accelerating onto a freeway. The slip would be indicated by a rise in RPM with no acceleration. The hard shift was a pretty firm bang.

Even though the dealer sucks, you have to be persistent. I had my car at numerous shops and 2 dealers before anyone could duplicate the problem. It generally was worse after the car warmed up.

 

[MBFire11]

I just replaced the 8 speed transmission in my 2012 5.0 r spec. There are numerous technical service bulletins on this transmission. Lots of write-ups on this forum also. Mine was shifting hard from 3rd to 4th gear and slipping while accelerating onto a freeway. The slip would be indicated by a rise in RPM with no acceleration. The hard shift was a pretty firm bang.

Even though the dealer sucks, you have to be persistent. I had my car at numerous shops and 2 dealers before anyone could duplicate the problem. It generally was worse after the car warmed up.

I am shaving the same issue but it happens between 4th and 5th. Also noticing it more since the weather has warmed up. Any solution to the issue that you found?

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[Phantom520]

I am shaving the same issue but it happens between 4th and 5th. Also noticing it more since the weather has warmed up. Any solution to the issue that you found?

The internal transmission solenoid valves need to be replaced, but the parts are not available, and few repair shops would take on that job. Re-manufactured trans will cost 4-5k installed.

 

[PennyCat]

Thanks for your input. @Phantom520.

I put fuel injector cleaner and full tank of premium gas in on Wednesday. I noticed ithe car idles quieter and smoother, but the problem while accelerating still continues. I guess it's dealer time.

 

[MBFire11]

has anyone looked at having the TCM flashed with an update. There ahs been no clunking on my car yet but willing to look and see if that may solve the issue. Other forums that i looked at suggested that this may fix the issue, but again no one followed up to say if it worked or not.

 

[Phantom520]

has anyone looked at having the TCM flashed with an update. There ahs been no clunking on my car yet but willing to look and see if that may solve the issue. Other forums that i looked at suggested that this may fix the issue, but again no one followed up to say if it worked or not.

The dealer updated the TCM with no improvement. Replacing the transmission was my only option when the shifts were so hard the car was almost undrivable.

 

[MBFire11]

The dealer updated the TCM with no improvement. Replacing the transmission was my only option when the shifts were so hard the car was almost undrivable.

I have just noticed the shifts and it is vey minor. Only clunked into gear once. Gonna change transmission fluid and get dealer to update TCM to see if that changes anything.

Car has 87000 miles but I would not be surprised if it was original fluid. Just replaced the battery and that was original as well.

 

[schniper23]

I have the same issue. It happens periodically. I found a website which sells valve body assemblies with all the solenoids repaired, it was about 400-500$ which isn’t bad. I read up a lot on this issue and apparently the main problem is the 2-3 and 4-5 solenoid which also controls reverse. These go bad as they are susceptible to debris and wear with harsh driving with engine under load. Fluid might help but a dirty or worn solenoid kinda has to be replaced. Hopefully this fixes the problem, I have 100,000 mi and expect it to last another 50 at least

 

[pete268]

The internal transmission solenoid valves need to be replaced, but the parts are not available, and few repair shops would take on that job. Re-manufactured trans will cost 4-5k installed.

This ended up being the issue with mine. Dealer was ready to replace the transmission, but they told them to do the solenoid first and it worked.

Interesting with some of the other comments. I had it in for some service and some of the undercarriage didn't get put back on properly and I hit some deep water. That picked up grass and some other debris and this problem along with a few others started.

 

[MBFire11]

This ended up being the issue with mine. Dealer was ready to replace the transmission, but they told them to do the solenoid first and it worked.

Interesting with some of the other comments. I had it in for some service and some of the undercarriage didn't get put back on properly and I hit some deep water. That picked up grass and some other debris and this problem along with a few others started.

So my issue with the transmissions has gone away since the temperature has dropped. Last service I had the tech check the transmission fluid and there was no discolouration or other issues with the fluid. What I have noticed during the summer was that when the constant temperature was 90 degrees Fahrenheit or above, the transmission would shift weird. Now that the constant temperature is cooler I have had no issues with it.
The only other thing the tech did was to reset the adaptive learning for the transmission. Thinking the fluid in the transmission is not the correct grade. May switch it out at next service.

Anyone else experience the Change in shifting with cooler temperature

 

[shahhere]

Whats are you guys getting quoted for Trans Flush? My dealer was $199 and I guess with things going up is now at $295 and another dealer is $315........rear diff is quoted at $150-$175.

Funny thing is that they used to loan a car for Genny and Equ but they no longer have them as they are gone for long term repair and are telling me to go rent a car across the street lol.

Shahhere

 

[PennyCat]

OP here, back to follow up.

After driving off the full tank of premium gas with fuel injector cleaner, the issue improved to the point that I stopped investigating other solutions. I will do tank of premium plus FIC annually after routine tire maintenance.

Thanks to all who provided suggestions. All the best to those still searching for solution to similar issue.