Flat Spots on acceleration

Hello all, I have a 2008 Cayman S , and over the past year, I have noticed that the car has been getting more difficult to drive smoothly at low speeds. I feel "flat spots" (for a lack of a technical term) in the acceleration. Right around 2,000 rpm and 3,000 rpm. The car is also bucking around a lot more than she used too. I typically try to keep the RPMs above 3,000 when I drive, but in traffic that is not always possible. The car seems to be bucking more at lower rpms than in the past. Does anyone know what may be causing these symptoms? Are these symptoms a precursor for any larger issues like the IMS problems? Any help would be appreciated. Thank you

Might be a locked up flywheel. Recently had to replace mine for similar symptoms.

If the IMS was involved you would not be still experiencing these symptoms after a year's time. With no error codes there's not much to go on. How many miles on the car? Are the spark plugs due to be changed? How about the fuel filter ? Is the air filter reasonably fresh? Is there any correlation to this behavior and what gasoline you put in the tank? There is the possibility of the AOS going bad. It can cause running issues and yet not generate a CEL with one or more error codes.

Car has 32,000 miles. All regular service is up to date. The behavior is not correlated to gas type, as it is happening all the time. Next time i bring it in for service i will mention the behavior and see what they say. Thanks

I wonder if you are experiencing the dead spot described in this thread? http://www.planet-9.com/987-cayman-...-cayman-boxster-problems-complaints/50664-anyone-ever-figure-out-dead-spot.html

I also had a similar concern but more like the earlier posted "flat spot issue". Adding a Remus exhaust helped somewhat. Installing the Softronic flash reduced the issue even more. Later I put in an IPG plenum and the flat spot went away completely. Most of the time I am running higher than 3000 rpm anyway. Jim

This is why you feel that. It is a dead spot in the torque curve of the engine. I feel it especially when I'm in auto mode on my Tiptronic.

Most likely an oily mass air sensor. Your experiencing the typical symptoms. Clean it with MAF only cleaner and the intake tube around it too.

I understand the point you're making, and it makes sense, but it's not what I (and I think others) feel. I feel a very brief complete lack of power. It feels like this blue line, but even briefer than I can draw due to the width of the line.

Thanks everyone for the input. I will keep you upated as I work through the isues. Sent from my GT-P7510 using Tapatalk HD

This discussion is from 8 years ago, so I wouldn't expect any reply from the OP you are replying to considering they haven't logged into the site in 6 years. This is well known on the 981 and base 911 Carrera which shares the same engine. You can see the torque dip on any stock dyno chart. Headers with sport cats and a good tune can resolve it, and give you a nice performance boost as well This old thread is concerning the previous 987 generation of car, and the new 981 like you have did not appear until 2013/2014. At that time there were no tunes because the ECU encryption had not been broken, so best to start any further questions on your specific car with with a fresh thread in the 981 discussion forum where you will get more accurate and current info Welcome and good luck with the new ride!