I've asked before about the smoothness of the flat 6 of the 997.2. Mine has never been smooth since purchasing a year ago. It has 75,000 miles, new motor mounts (OE) and transmission mount. Also all new plugs and coil packs. This probably wouldn't really be noticeable but for the fact my old 986 is dead smooth. So I downloaded a NVH program. It successfully pointed to a wheel balance problem. Now it shows a "First Order Engine Speed Related Vibration." Worryingly, I read this is normal only for 3-and 5-cylinder engines and some V6s. Suggested problems include harmonic balancers, crank pulleys, trans input shaft, crankshaft and several others. Crankshaft?? Now I understand this is only a program taking in data and spitting out some other data, but would like to hear some others input on this. And other than this vibration, the car starts and runs fine. There is no oil consumption or other symptoms.
Discussion summary
YOUR RESEARCHEngine (Not Good) Vibrations
1 matching discussions were examined; no attributable action/outcome evidence was detected. No consensus or repair conclusion is claimed.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Read captured repliesInsufficient extracted evidence does not mean there is no answer in the original discussions.
1 matching discussions · 4 captured posts examined · 1 partial discussions
Coverage and how to read this overview
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
4 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
- Planet-9: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T070717Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
The NHV app sounds interesting. Can you provide a link to it? I wonder if the authors of it even considered an H6 layout..
I don't know if they have considered a flat 6, but I know mine isn't smooth. To confirm, I had a new GTS 4.0 out last week and it was dead smooth. NVH: NVH For Android - Apps on Google Play
I looked on their website - and yes - they include quite a few Porsche H6 models. The only drawback I see is the price. $100 for software for vibrations - if it's a private user - is a bit rich.
This is a source reference. Confirm exact model applicability in the original material.