one-rennlist

Hi all

I finally pulled the trigger and am very happy with the addition of a 997 GTS Cab 6MT to my garage! I noticed two things with my car though:
- Engaging second gear (coming from first) was heavier than the other gear changes and made slight grinding noises (happened with cold engine and transmission, it's fine when both are warm)
- Acceleration from low rev's (ca. 1'000 RPM) without gear change shows a slight pause in power delivery when passing 2'000 RPM (independent of engine temperature)
- Lot of audible high pitched rattle (valve play?) when idling (independent of engine temperature)
- Fluctuating idling RPM of about +- 100 RPM (barely discernible movement of the RPM needle)

Any ideas? As for the two last three issues please know I'm no expert on how a B6 DFI should sound and/or behave...

Nicola

Para82

I would get that transmission looked at, you shouldn't have any grinding. They can get notchy in cold weather, i've had 1st gear be a little stubborn when first driving on a cold day, but that's fairly normal. The grinding is something i've never experienced in 72,000 miles of driving my 6MT 997...

one-rennlist

Regarding the switch to second gear: After a cold start today there was no grinding, just a tactile feeling of the teeth giving resistance when engaging.

scorcherjf

'12 GTS here - I noticed a rattling sound during idle after the car has warmed up. Sounds like a ticking but random, with no rhythm or pattern, similar to the heat shield expansion. Asked the dealer last time I was in, they said it sounded normal, but I never heard it on my older 997.2 C2S.

The power hesitation at 2k rpm sounds similar to the 991 problem that a lot have reported - partial throttle hesitation at 2k rpm that wasn't the variocam kicking in at ~3k. Some have said an ECU update fixed it but a lot of people are still trying to figure it out. As for my car and my previous 997, I don't notice any hesitation at 2k, only a slight "bump" in power at 3k which is the variocam I believe.

one-rennlist

Very valuable info! The symptoms are very similar indeed. Question is whether Porsche acknowledges the problem and there is a fix for it...

Nicola

one-rennlist

Could it be a Mass Airflow (MAF) Sensor issue? See here: http://www.6speedonline.com/forums/9...-2500-rpm.html

Incidentally the salesman who sold the GTS to me also mentioned the MAF when I asked about the fluctuating idling RPMs after the test drive. He assured me the idle would be ok after they had done the inspection. It's not really gotten better though, so I will bring my baby to the doctor next week...

one-rennlist

Or lambda sensors: http://www.6speedonline.com/forums/9...sy-tappet.html

one-rennlist

Happy to report that after driving the car how it's supposed to be (it's got a 408hp 3.8 B6 for a reason!), the strange hesitation in the low ranges is much better now. I guess the car was not driven right by the previous owner. The rest I'll attribute to character.

Funny story: My wife had taken it to the office today. When she returned to the parking lot some random guy, unlocking his Boxster, was smiling at my wife trying to impress her with his car. He wasn't smiling anymore when he saw what the lady was driving.

j beede

I don't think accelerating from 1,000 RPM in any gear other than first is recommended.

Hella-Buggin'

You should never be at 1k rpm in any gear but first. You are lugging the engine and that is far worse than doing 5k rpm in first.

Are you slamming it into second? They all notch a bit whine cold between first and second when cold. It has to do with the steel synchro gears. You just need to baby it until it warms up. If your issue is beyond that then take it in before you lose a synchro completely. It could be out of alignment.

one-rennlist

No slamming and no engine lugging happening here either, gentlemen. The gear change between first and second is really only notchy when cold, so it seems to be ok. And yes, when the car hesitates from 1k to 2k rpm it also happens from first to second gear, wiggling the car, so I feel like a learning driver unable to cope with the clutch. Though like I said it's rare now, hope it will disappear completely.

one-rennlist

Ok, had my car checked at the dealer. On a test drive their mechanic could reproduce the hesitation at 1200 RPM and to some extent also at 1800 RPM. They cleaned the throttle body (technical measure proposed by Porsche) but the issue persisted. However they had another GTS in for service and its engine showed the exact same hesitation at 1200 and 1800 RPM on a short drive where I was in the passenger seat!

beden1

I had the hesitation problem when I first bought my 2012 GTS new. It's been a few years now, and I forget exactly what the dealer did to fix the issue, but I no longer have any hesitation whatsoever. I remember the service manager telling me that they had seen this issue many times before on 997s and they immediately knew what to do for a fix.

Are you primarily driving in sport mode? I remember having this issue more when using the sport mode than when in normal mode. I have a manual transmission.

As far as engine noises when idling, my engine sounds as smooth a silk. I had an '09 Corvette Z06 that had valve issues. I was able to hear the ticking/tapping sound when accelerating in neutral with my foot on the pedal while standing outside listening with the hood open. The ticking/tapping noise grew louder when accelerating from idle to around 4,500 RPMs. I had it checked at the dealer and they determined it needed a complete valve assembly replacement on the exhaust side. Many C6Z06s have this problem which appears to be a GM design flaw.

My idle is rock steady and does not fluctuate.

one-rennlist

I don't have Sport Chrono, so no Sport Mode... It would be great if you could ask your dealer what was done to your car to fix the issue and report back here!

beden1

I'll ask them. My service for this issue was about 3 years ago.