Does your tachometer needle wiggle when your car is idle? Mine idles around 700, but it really wiggles/jumpy. Not what I am used to with my Audi S4, which is solid at idle.

Im also having misfires in all six cylinders, I wonder if this has anything to do with it?

Any ideas?

 

Mine is rock solid, and was even when I was experiencing the misfire issues. My misfires were on one bank, not both, so... it's hard to say.

It should be rock solid. It's electronic, like the other gauges. Shouldn't wiggle, IMHO.

Ask the dealer to run an over-run check with PIWIS. I don't intend to be gloomy but there might be issues with the motor - the sooner you know, the sooner you can get it fixed and enjoy the car! Leverage that warranty, and if you get no satisfaction from the dealer, try another. You shouldn't have to deal with this, you spent too much money...

-don

 

What is an over-run check?

I agree, that I should not be dealing with this. Im not too happy about all the issues on a "new to me" car.

Thanks for your input.

 

The dealer can check to see if the engine was forced above the redline. This is a purely mechanical phenomenon - for example, a mis-shift into second gear (instead of fourth) when redlined in third...

There are 6 levels of over-revs. Level 1 & 2 are normal, you get them from bumping off the rev limiter. Four and higher denote possible engine damage from extensive over-revving. Remember, this is an interference engine (as almost all are today) - if you force the engine to rev too far past the redline, you can cause piston-valve contact.

Again, it would take level 4 or higher overrevs to cause issues. They can also see the engine run hours when the over-revs occured, so they'll know that it happened before you bought the car...

Again, just being cautious and trying to reduce your downtime. Now is the time to enjoy your new Porsche, not spend days at the dealer... but I'm sure you know that.

Keep us posted on what they tell you.

-don

 

Just to clarify, wprater - level 4 over-revs don't automatically infer engine damage... the number of ignition events are recorded by the computer, they will show as numbers per level.

There may be thousands at level 1 and 2, that's normal if the previous owner used the rev limiter as designed. If there are hundreds of events at level 4 (or above), there could be damage.

 

Hi,
I would run higher octane gas. Try adding five
gallons of racing gas to a tank.
Paul

 

Thanks for the info and clarification. The car is already at the dealer and they will be conducting tests. I've also asked them to get me a report on the over-revs.

Thanks!

 

Just picked up there car after a week at the dealer. They have no explanation for the misfires. They drove the car, did experience them. They ran a compression test (everything passed OK), did an engine overrun test (only 4-5 stage 4's no 5-6's), and replaced the spark plugs.

The engine check light is off, however, the tachometer still wiggles. Im not sure if I should be upset or just deal with it.

If its not supposed to wiggle (at all) then they should probably take my car again!

Thoughts?

 

My wiggles too.

The solution to this problem is to not be OC about it.

 

its normal engine rpm can vary especialy on a e throttle car as the car adjusts the throttle body to maintain idle. Every 997 does it i promise

 

How much wiggle is in there? And how fast does it wiggle? <this sounds silly, but... :->

 

A wiggles a "little" especially after a high speed run (the tach, that is).

 

The tach on my 05 wiggled and I was told it was normal. My 07 does not wiggle as of now, 1500 miles.

 

Not much at all, the wiggle is on the fast side I'd say. I had a suspicion it may be normal, so that's why I asked. Now Im getting mixed results.

I was more concerned about the misfires on all 6 cylinders. I had a suspicion the wiggle was from the misfires, but apparently its not.. unless the dealer has a way to put a "fault on hold" for a while.

 

dealers canot put a fault on hold, misfires can occer if a car is started with a low battery
low or old gas, or to much water into the air cleaer at the car wash.
I wouldnt worry about it
the car is smarter then you think if theres something wrong it will tell ya