Planet 9

A bit of an out there one but I have 6000miles on car and just noticed (never noticed before) that tacho needle dances around a little bit at idle when car is both cold and warm. It seems to bounce around between 600-700rpm and is quite pronounced. Almost like the old days when you had electrical surge when indicators on. I am absolutely sure I would have noticed it before so I assume it is new or maybe I just focus on it now! Car still screams around to full revs and no noticeable issues other than a bit of a lumpy idle.

Any thoughts on whether this is normal?

PS got my first ticket yesterday

Cheers

Normal on the cars I've owned.

Not really normal for a late model Porsche, especially the "dancing" part of it. The tach can move up and down at idle like you're talking about, but when it does go up and down by a couple of hundred RPM, it's usually a slow movement... I would say, not a big deal if everything else is ok, the motor seems strong and there's no misses, etc. Point it out to the dealer the next time you take it in for service or something more alarming.

brad

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22-year PCA Member
PCA DE Instructor

Had the same problem, then I noticed I waas resting my foot on the gas pedal. Not with any real pressure mind you, but that baby is sensative! Also, I know its counter intuative, but it was making it idle LOWER.

I dance around a little bit at idle.

Mine is rock steady at all but start up. This smacks of a fuel filter issue (at best) or an injector/timing issue. I'd take it in. Either way it should be warr. rep.

Maybe your gas is inconsistent or the fuel lines are a little blocked?

Or maybe your engine is just dancing!

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resident comedienne

2006 Cayman S - Speed Yellow, Black Interior, Yellow Seat Belts
Sports Chrono Package, 6 Spd, PASM/PSM, Bi-Xenon headlamps
Carrera S wheels 19" - Mich PS2, Colored-crest wheel cap
Auto climate control, Heated seats
PCM 2.1 Nav, Denision ICE-Ipod, Bose Surround
De-snorked, Evo V-Flow, Clear Engine Cover
GT3 Bumper with LED Dayrunner lights (NR Auto)

i had this thing too. the dealership checked and said they need to replace the air mass sensor. after that everything was okay.

seems to have almost settled down after about 300 miles so suggestions re dirty fuel filter may have been on the money. Thanks for your feedback

Mine does that, but only when I find that I am resting my foot on the pedal. When I remove my foot it was fixed.

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mine does it too...

Mine seems to dance around a bit at idle too. Seems more noticable once the car has warmed up. The needle will sit at 650-700 RPM then jump a small amount, about 50RPM. It will still there for maybe a split second, then return to the original RPM.

Been driving the car for over a year and sitting in traffic, my eyes just fell on the tachometer and noticed that the needle reading was about the 600 RPM notch when idle waiting for traffic to move . I'm asking myself WTF, shouldn't the needle be at zero when I'm idle. So I gather from the responses here that this is normal. (first manual transmission).

A car's Tach measures engine RPM. After starting, the engine is always turing over, even at idle. Normal idle RPM depends on the engine type, size, and state of tune. Cayman engines seem to idle around 600.

Mark

Yeah, I been wondering the samething.
I've noticed this only after I did the ECU upgrade. It moved up and down but in a super small increment. I hope this is not a warranty...cuz I already have the SRP installed as well. This happens when it's in neutral.

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Proud owner of Midnight Blue Cayman S. (06-30-08)

Thanks Mark. For a second there I thought I might have to take it in.
Cal