2019 MT-82 lunges forward on upshifts

[MasterCylinder]

A lot of the s550 guys in general experience rev hang until it is tuned out. It is done on purpose by the manufacturer for emissions reasons. Ultimately it is annoying as hell. You just have to shift slower and i hate it.

Sponsored

 

[w3rkn]

It is most likely the rev-matching...

 

[emcee1011]

I have the same issue, in 4th gear the most obvious. It's definitely a rev hang and you are shifting too fast sadly.

 

[gregckach]

If you feel inclined, update this thread if you hear anything about this.

So quick update. I could reproduce the problem of excessive rev hang in the 3>4 shift about 50% of time leading up to my first service with the dealership with or without rev matching turned on. But during the day or two beforehand and on the way over to the dealer I couldn't reproduce it at all. I had just topped off my oil (it was at the low mark already which kind of surprised me lol) so maybe that was part of the cause. Since then I've got another 800 miles on it with some hard driving as usual and it's only happened once. Basically all I've done is top off and then change oil. If I can get it happening pretty regularly again I'll take it in and report back.

 

[Mustang_Eh]

So quick update. I could reproduce the problem of excessive rev hang in the 3>4 shift about 50% of time leading up to my first service with the dealership with or without rev matching turned on. But during the day or two beforehand and on the way over to the dealer I couldn't reproduce it at all. I had just topped off my oil (it was at the low mark already which kind of surprised me lol) so maybe that was part of the cause. Since then I've got another 800 miles on it with some hard driving as usual and it's only happened once. Basically all I've done is top off and then change oil. If I can get it happening pretty regularly again I'll take it in and report back.

Interesting. Thanks for the update, although I'm confused how rev hang relates to engine oil being topped off.

I too notice that it's not happening 100% of the time. Sometimes it shifts perfectly, but sometimes I get really bad rev hang 3 > 4 > 5 > 6 - like every gear the car lunges forward.

 

[gregckach]

Interesting. Thanks for the update, although I'm confused how rev hang relates to engine oil being topped off.

I too notice that it's not happening 100% of the time. Sometimes it shifts perfectly, but sometimes I get really bad rev hang 3 > 4 > 5 > 6 - like every gear the car lunges forward.

Yeah, I don't really know either. But that was literally all that changed so I figured it was worth mentioning But one thing I heard recently which may make more sense is a bugged throttle position sensor or something related to it. Today I was driving back from work and noticed something that has me wondering if that might be it.

I was driving at a regular speed in 3rd gear around some side streets. I lifted off the gas to coast to a traffic light and the car just hesitated for a moment before actually closing the throttle all the way. So say I was at 3,000 RPM when I lifted. Rather than slowly starting to drop as the car slows down, it just hangs there at 3k. After a couple seconds it then starts to drop and you can hear the overrun from the exhaust. Normally that happens right away, but not this time. Coincidentally, whenever I got rev hang previously at speed it had the exact same behavior - wait a few seconds and the revs drop like normal. If I can get it happening again regularly it's definitely going back in.

 

[Mustang_Eh]

I experience throttle being open for a few seconds at low speed sometimes as well.

 

[EFI]

Isn't this a sign of the automatic no lift shift that the new PCMs do now where it keeps the throttle open when shifting over 5k?

I know ever since I got the PP2 tune on my 16GT that enables no lift shift at >85% throttle and >5000rpm doing the shift normally is a little funky as my timing interferes slightly with the NLS feature. I either have to do it very fast, or just let the computer do it's own thing. But if I try to do a semi-lazy shift past 5000rpm now it lunges a bit.

 

[thasuperdude]

So, after reading through a few threads, I think I can deduct it's a computer thing and not mechanical. If it was the heavy flywheel it'd happen every time. It only has happened after I've done some spirited driving in the mountains and go to back off. The engine holds the REVs for a good 1-2sec. That's not a flywheel thing. I guess that it's burning some of the extra exhaust gases for emissions.

I get the slight gear noise as well, so it sounds like all things are normal, just new to me/us. Even the GT on Smoking Tire had it. I'll chalk this under, things I can live with/why I have a warranty.

Has anyone replaced the their flywheel, and did it remedy any of these issues?

 

[rebellovw]

I’m not noticing this at all in my 18.

 

[Ghost50]

Mine rev hangs too.

Especially in the higher rpm bands. It also has the whizzing noise or whatever seems to be common.

Can the rev hang be tuned out of it by Lund/PBD?

 

[Black19GT]

My ‘19 GT does the same thing. If I’m driving it hard through 3rd and 4th (5-7k RPM) when I shift into 5th and 6th the car will really lurch forward. I’ve tried releasing the clutch really slow but it still lurches as soon as it grabs.

I’ve also experienced the throttle staying open driving around the city at lower RPM as well. Sometimes takes a second or two to go into vacuum and decelerate. Plan on bringing this up to the dealer when I’m there next week as well.

 

[Mustang_Eh]

My ‘19 GT does the same thing. If I’m driving it hard through 3rd and 4th (5-7k RPM) when I shift into 5th and 6th the car will really lurch forward. I’ve tried releasing the clutch really slow but it still lurches as soon as it grabs.

I’ve also experienced the throttle staying open driving around the city at lower RPM as well. Sometimes takes a second or two to go into vacuum and decelerate. Plan on bringing this up to the dealer when I’m there next week as well.

Keep us posted on what they say it is. Exactly the same symptoms as me.

 

[Condor1970]

When operating a clutch rated for up to 800hp with a dual mass flywheel, I wouldn't expect much to go very "smoothly" when shifting above 5,500rpm.

 

[Mustang_Eh]

When operating a clutch rated for up to 800hp with a dual mass flywheel, I wouldn't expect much to go very "smoothly" when shifting above 5,500rpm.

Nobody is talking about luxury level seamlessness. But when one car is lunging forward rather violently, and another does not (under the same conditions) what does that tell you? I drove plenty other S550's and none of them exhibited such behaviour.

Sponsored