Driving issue at 3000 rpm

[ekstroemtj]

Dear forum members, i try to find out what could cause this issue and maybe someone has an idea what to look for.

Cayenne is driving fine. At low speed no problems. Kick down getting speed very easy. High speed no problems. Just between i feel its behavior is not normal. I have this problem allready some weeks. Porsche cant find anything. No codes so far.

Last week i drive 1000 km non stop and specially focused on the issue.

My impression, better to say what i learned from this trip. The car acts just strange in the range between 3000 and 4000 rpm. In any other situations no complain.

Strange means its not running smooth, accelaration feels like there are very short moments when the engine isnt getting enough gas. Some kind of very short stottering but you can really feel it. If i pass the 3800 / 4000 rpm its fine again.

Maybe somebody has a clue what it could be.

The car has new coils and short time ago got new throttle body and new fuel pumps. Cayenne S , 2004

Thank you

[mudman2]

Wow I would have said the things you already fixed. I would recheck the coils first, just a visual inspection

[ekstroemtj]

Wow I would have said the things you already fixed. I would recheck the coils first, just a visual inspection

Thank you mudman2 .... But wouldnt a coil problem make trouble in all RPM ranges and not only at arround 4000?Tom

[mudman2]

not all the time you can drive thru it if its only 1, any error codes ?

[ekstroemtj]

There was one code: oxygen sensor. They cleared it and it didnt come back.

Nothing else which is visible at PIWIS.

[darrinsmith]

I had a similar problem but I was getting the camshaft angle implausable error (0021 from memory).

I switched to shell helix ultra 5W40 from mobil 1 5w40 and problem solved!

Car runs heaps better on Helix than mobil 1.

The cam timing seems to be really sensitive to oil types, a bit like mitsubishi's too.

Thanks

DS

[ekstroemtj]

Thank you for answering. Oil could be but in my case i dont believe. I change oil after 5000 km and use mobil 1 or shell helix. Happens with both.

Regards

[RFM]

Maybe the engine run too lean between the specified RPM by some reason, you can see the values when driving, using a PIWIS.

[ekstroemtj]

Thank you for this idea.

You mean really during DRIVING or would it be possible to notice in the shop just when they bring it up to this RPM range?!

[RFM]

Indeed, PIWIS provides the ability to store values during a test drive.

[mpronto]

Hey Eks, did you manage to solve the problem?, I have the very same issue, low revs. the car is fantastic and smooth, after 3k onwards it starts to missfire, coils and plugs are new, also did the filters etc.. pumps have been checked and seem ok, mechanic said it might be low fuel octane level, so I added some toluene based thinners, to boost octane, in fact car runs better but still after 3k problem is there. Only once did it stop for a short time when I did a 600km trip, at a steady 140kms p/hr, then after driving stop and start it came back!! let me know if you have progress.

[ekstroemtj]

Didnt found out so far. I have to take it to porsche next days. Low octane is not the reason. I use 102 octane and still coming arround 3000 rpm.

Its in some way frustrating . Porsche mechanic told me it cant be related to coils or plugs. This kind of problems would be causing trouble in any rpm range. I keep you informed

[swpender]

Do you feel it under the armrest? I've just started to feel same on accel under mine. Had a valve issue but didn't swap out o2 sensor and the vibration seems to have started at the America time.

At the same time.

[ekstroemtj]

I still have this issue. Talking several times to mechanic. I guess they maybe did something wrong when they worked on my fuel pumps. Just my opinion. I will ask them one day to open fuel tank and check a lines there

[mpronto]

Hi Eks,

I recently removed my catalytic converters, as I noticed the smell of sulphur when revving high, also where I live the fuel quality is very bad, the intermittent cuts have gotten a LOT better but still a little when revving past 4k (although the nice thing is the car sounds fantastic!), am now thinking of changing the air filters, and putting in K&N´s this might help it "breathe" better. When I connect to the computer I get a message of timing advanced, which I think might be due to low octane fuel, as I can clear it and it comes back after driving for a couple of days. Will let you know if the airfilters make any changes.

[mpronto]

Indeed, PIWIS provides the ability to store values during a test drive.

Hi RFM, do you know what values should be recorded for the lean or rich settings while recording, ie.. what would be considered lean or rich?

[ekstroemtj]

Thank you for sharing your information. I still have the issue. Car just had a service. These guys are not able to clear the problem. I ask them to open fuel tank and check everything. I am not a specialist but from my knowledge and experience it really feels like a fuel pressure problem.

I will see, hope next week i will know more about.

[ekstroemtj]

Just wanted to inform you about how this problem get solved.

As i was writing before the car had a strange behaviour at arround 3000 rpm and again at 5000 or more.

No codes.

Take the car to the shop. They opend the tank. Replaced the left fuel pump. (The other one was done few month ago).

Make a long test drive today. Everything fine. Car runs great

[mcbit500]

Dear forum members, i try to find out what could cause this issue and maybe someone has an idea what to look for. Cayenne is driving fine. At low speed no problems. Kick down getting speed very easy. High speed no problems. Just between i feel its behavior is not normal. I have this problem allready some weeks. Porsche cant find anything. No codes so far. Last week i drive 1000 km non stop and specially focused on the issue. My impression, better to say what i learned from this trip. The car acts just strange in the range between 3000 and 4000 rpm. In any other situations no complain. Strange means its not running smooth, accelaration feels like there are very short moments when the engine isnt getting enough gas. Some kind of very short stottering but you can really feel it. If i pass the 3800 / 4000 rpm its fine again. Maybe somebody has a clue what it could be. The car has new coils and short time ago got new throttle body and new fuel pumps. Cayenne S , 2004 Thank you

The car has new coils and short time ago got new throttle body and new fuel pumps.

Well you threw us of the scent a little with this information.

[ekstroemtj]

Sorry if i made a mistake. The car got ONE new pump some time ago because porsche told me the left one is working fine. So they told me not neccessary to change.

After some time the problems started. From the the very beginning i asked thrm to check the work they did in the tank.

After monthes driving arround now with the problem, i asked them to change the other pump too. Thats what they did yesterday.

[mcbit500]

When I changed mine ( same symptoms as yours before finally one gave up the ghost completely ) my tech told me that Porsche advised changing both pumps and the filter at the same time. Makes sense on a higher mileage vehicle as both are likely to be in a similar condition.

Glad to hear you got it sorted in the end though!

[ekstroemtj]

The car runs WOW now, what a difference. It feels like s different car. After all this trouble i can recommend to everybody who has similar problems. ..CHECK THE FUEL PRESSURE OR THE PUMPS

[mudman2]

I was told by dealer that pumps should be replaced in pairs but most people don't due to cost

[mcbit500]

I was told by dealer that pumps should be replaced in pairs but most people don't due to cost

If you're into the car for the long term though it becomes more expensive to do the same job twice.

[mudman2]

Mine was traded 2 weeks after the first one went, only time in 130K miles I had a breakdown