955 idle uneven
 

hello friend
i have a problem with my pig
cayenne S, 2004r, 4,5 V8, m48.00

I have a problem with uneven/rough running cylinder on idle. Little rough on idle. No any codes in engine
On piwis I tested in various ways and found a problem.
In option "Uneven/rough running cylinder" my cylinder number 3 has a different value in than the rest of the cylinders. All cylinders have 0,5 or -1, my cylinder number 3 have value 3,58. Why ? :( Low compression on this cylinder ? electrical problem ? All spark plugs and coils are new. I have this car for 4 years, there have always been idle vibrations, little vibrations, almost imperceptible, I have already driven 30,000 km with these symptoms..

Hi Dawdoo.. welcome to the Rennlist Cayenne forum.

I assume the numbers you are quoting are from the PIWIS? It should explain what those numbers mean.. if it's adaptation for a cylinder I'd first look at coil/plugs (which you've done), then compression. You didn't give us the year/model of your Cayenne, so all info passed on here should be considered wild-ass-guesses (WAG..) And on some models - little vibrations can be a sign of failed engine upper strut support or engine mounts.

oh sorry :(
cayenne S, 2004r, 4,5 V8, m48.00

Value on cylinder 3,58 is from piwis, from meansuring block name "uneven/rough running cylinder"

I have a new toruqe arm (black) and all coils and spark plugs

It would be interesting to see what the compression is - all cylinders.

Ok I will check the compression. Is it possible that the value is different by exhaust leakage ? When I stand on the right side of the car, I hear a quiet ps ps ps ps ps ps.
Cylinder number 3 is on the right side of the car, on the right head, maybe because of a leak in the exhaust system is the problem ?

look at video, turn up volume

Dawdoo - afraid I can't hear it in the video.. I hear a bit of injector noise, but can't hear a leak. Perhaps it's my ear-buds... I would imagine an exhaust leak could cause a slight idle problem...

Original Equip ? header #1 Cat Junction might need a torque wrench

original equip. Okay, first I have to check the compression.


Hmm, now I hear the second problem, whistling, howling in the background, you can hear it on the film

Oil/ Air separator,

2 weeks ago I installed a new one AOS

Check the PCV breather/valve system. If they are saturated with oil - you got a blowby issue...

How many miles does your Cayenne have? Worn motor mounts sometimes give the illusion of a rough running engine.

mileage is 136k miles
compression in my cayenne is:
cylinders:
1-160psi
2-153psi
3-147psi
4-145psi
5-160psi
6-166psi
7-160psi
8-160psi

Corrections for camshaft position sensor is -7 and -13
Sometimes at low rpm on idle, feel slightly uneven work. Feel it in the driver's seat, gently vibrates. In addition, the engine runs quietly and evenly
I made a compression test from number: 8,7,6,5 and second side: 1,2,3,4.
photo: CLICK PHOTO

Cylinders 3 and 4 seem like they're a little on the low side for compression. But I'm not qualified to say if its a problem or not.

As far as the symptoms you're describing, I had the same and I just resolved them yesterday by finding and patching a vacuum leak.

If that test was done hot then around 180 is healthy. Unfortunatly PIWIS doesn't come with instructions:cheers: