Question about thump/kickback in 6th gear

Hopefully, I am asking this question in the correct category. I am not sure if it belongs here or in the Techical category. I received my CS 2 days ago and have already driven over 200 miles, going no place in particular. Thus far the car exceeds my high expectations. It is simply a wonderful car- looks, handling, steering, braking, shifting, engine,.... I do have one question/concern about the car (other than the whistling roof rack). In driving the car in 6th gear, I feel a thump/kickback feeling (may even hear it) when I take my foot off the gas pedal. I do not notice it in any other gear. I have been on the highway a lot and have been varying my gear and rpm per the break-in period- using 4th, 5th, and 6th. If I take my foot off the gas pedal at around, say, 3000 rpm in 6th gear, the thump/kickback is very noticeable. Is that normal or an indicator of a possible problem? It does not occur in any other gear. Thanks! Doobydarby

Hmmmmm........ I didn't notice anything like that while driving mine. If it's easy to reproduce, I would take it down to your dealership and take a Service Associate for a ride and show them. However, there might be a difference between our driving styles. I have a serious obsessive compulsive pet peeve about un-smooth driving of a manual shift car. Really, it's quite bazaar, and now it's rubbing off on my girlfriend (we'll get out of someone else's car and Ina will be like, "Oh my god. Did you see how rough he was shifting? Where the heck did he learn do drive."). My shifts, downshifts, accelerations and decelerations are all done with laser precise smoothness, in most case smoother than any automatic shift transmission can deliver. In fact, the first few days of driving my car, my primary focus was to develop the familiarity with the Cayman needed to achieve this. So I may be the wrong person to respond. Are you coming off the accelerator very abruptly?

Doobydarby, I was just reading your other thread, very exciting by the way, and I saw that you are really enjoying the 'Sport Chrono' feature. This kind of supports my suspiscion that you might just be coming off the throttle too fast. I noticed with my car that with Sport Chrono on, it's difficult not to be abrupt with the throttle, at least not until you spend some serious seat time behind it. This thump, is it happening in both SC modes? That might rule out my suspicion, or confirm it. Give it a try.

Gator Bite Thanks for your 2 responses. I try to be smooth in shifting etc. I think that the thump is independent of whether I am using the sport chrono or not, Besides, it never happens in 5th or 4th gears, only on 6th. I think that I progressively let up on the gas pedal, not too abruptly. I placed a call to the service department and they will return the call soon, hopefully. The car is awesome! Engine even more responsive than I anticipated and I haven't even gotten into the heart of it, not exceeding 4200 rpm yet. DoobyDarby

Gator Bite I was called back by the service manager. He said that the thump was normal, being a function of gear ratios. 6th gear is less than one, and the others, per the service manager, are all more than one- actually I see that fifth gear is just about 1. He said if it was a transmission problem, it would occur in all the gears. So, I am no longer concerned, although I have no genuine understanding of what he said. Thanks for you help and interest. I appreciate it. Doobydarby

Doobydarby, My .02. The engine kickback feeling may also be a symptom of a new engine. I found the engine and gearbox extremely tight during the 1500 miles. Decending hills (6-7% grade) in 5th gear, my car would lose speed due to engine braking.

Gator Bite, Gee,I thought that I was the only "stick shifter" who drove like this & noticed other people's shifting faults. It's not easy being perfect!

balboa Thanks for the response. I have had the car for 2 days. The first day I found it a little hard to easily find and shift into 4th gear. The second day it was easier. The shifting seemed smoother and easier in just 2 days (it was fine from the start). Of course, I am getting used to the gear box and 6 gears- My BMW only has 5 gears. Also I found out yesterday that I am suppose to depress the clutch before I shift. Oh, by the way, I was just kidding about the clutch!! Delighted DoobyDarby

I just passed 3500 miles & the gear box is real nice now.

I don't see how it would be normal if it is indeed an issue and not something normal that may seem new to you. I don't have this issue on my 3 week old Cayman S, and what your service manager said makes no sense. Engine braking will be less pronounced in 6th gear, so lifting should not jerk the car unless you are at 150+ or something like this. I would take it in for a look. Doesn't sound good...Just my 2 pennies.

Oh, if it were normal, according to your service manger, then it should also happen in 5th, as 5th and 6th are very close in fact.

Doobydarby I agree with urbo73. The explanation of the service manager does not make sense. He says it's not the transmission but it’s the transmission ratios? I don’t buy it. I believe that the engine management system just shuts off the fuel injection until the RPM get down near the idle speed when you lift of the gas. It may be that it is not the transmission but the engine management system is acting differently in 6th gear. Either way it does not seem right.

mike He said that if it was the transmission, it would be occurring in all gears, not just 6th. I noticed it a lot around 3000 rpm. Doobydarby

I would take it in. What do you have to lose? Doesn't sound right to me. It could be a gearing problem, who knows? Hopefully nothing, but check it out.

Doobydarby, Obviously the concept of a "thump" is hard to discuss in a forum like this because of perceived differences and/or definitions of what constitutes a “thump.” That being said, it does not sound normal at all. I have owned 4 Porsches with various 6 speed gearboxes and would never describe any action lifting off the throttle as a thump. I would suggest you drive a couple of other CS’s off the lot under the same driving conditions you experience the “thump.” If you reproduce the same “thump” then maybe it is normal. If even one of the cars does not do it then I would lean on the service department to look into the problem. I personally would take the car back in and/or take it to a different dealership (even if you have to drive a few hours) as this does not sound normal. Given my above comment about different concepts of what a “thump.” I have been paying attention to my car for a few days. There is nothing with SC on or off that I would describe as a thump coming off throttle. The only thing that comes close is a feeling of let up (maybe described as a kickback by some with a thump) on an abrupt throttle lift while the car is under load (accelerating) but that is normal in any car and is easily reproducible in any gear. Just my $.02

I wonder if an engine mount is loose or broken. You'd notice that thump in all gears, of course. Seems to me it's worth having a different shop look at the problem. Russ

+1. Very well said and very good advice. I agree that describing something like this is very difficult and perceptions can vary wildly. With that in mind, I don't believe the service manager can accurately dismiss this over the phone without having sat in the passenger seat and experiencing it himself. It's very possible that if you do take him shotgun and show him that he will still say it's normal and nothing to worry about. But I don't think he can accurately do so without riding along. Take a ride to the dealership and put your mind at ease.

What harm is there in taking it in? If in doubt, have them check it out. In 6th gear at 3000rpm, in my Cayman S I'm at 75mph. If I lift abruptly - NOTHING happens. As it should be.

Btw, moving this to the "complaints" forum where i should have moved it days ago... brad

I took the car to my dealer and had them check the thump in 6th gear. The work order said that they found nothing abnormal. Interestingly, the day that I got it back, the thump was gone. Not sure what that means. Thanks for the insight and responses to my initial post. Sandy