955 Cayenne S - engine knock?

[Guest]

Even after changing everything on the ignition side and also the intake been updated with brand new throttle body & both maf's I got from time to time a DETONATION on the intake system. It can be heard only SOMETIMES if I accelearate and the engine is at low rpm and on a superior gear (many times when my car doesn't want to get from 5th to 4th or 3rd :) ). I used my tester but not even an error. maybe I'm not looking where I should look.

It's kind a backfire through the intake.

Some helping data:

1. My car is an US spec, and have about 75.000km

2. I have replaced the 2nd cats with fabspeed pipes, if that counts. Another interesting thing is that as far as I remember I havent heard this noise before instalation, or I might be wrong.

3. the gas here doesnt have the same octane numbers, BUT as it is wrote in the owner manual, you can feed it with any type of gas cause these cars can adjust timing when an inferior gas is used.

4. in the last monthes I used engine cleaners and octane booster, as an add to the used fuel. nothing changed

5. changed the sprak plugs with newer OEM ones. Should I get colder ones? Does anyone uses a different spark plugs?

my thoughts:

1. ignition timing - could be a bad camshaft angle sensor that seems to be working on tester?

2. a burnt intake valve

3. I dont know.

I know that this will not affect directlty the engine itself but the other components can be affected, and believe me I don't want to change the MAF sensors again, or the throttle body.

I don't want to change all the parts, like I did last year, so a better decision will help me.

any inputs are welcomed,

help is needed. :)

Ilie.

Edited March 23, 2009 by stealthTT

[Guest]

any clue?

[Loren]

Read the fault codes AND pending fault codes with the Durametric software, a PST2 or PIWIS tester and report back here.

[AlienGG]

My '05 V6 had a similar problem.

During any slightly-more-than-gentle-but-not-harsh acceleration, the RPM shot to the roof, while the transmission would not up-shift. Even at high RPM (red line) and 3rd gear, for example, the speed would not exceed 20MPH. Usually that ended up in a "bang" which shook the entire vehicle as if it hit a wall, and then everything went back to normal.

However, if the bang didn't occur, the gear would get stuck, even if the vehicle was parked and the engine was turned off. If you check out my attachment, you will notice that the vehicle was at 3rd gear when the engine was off, and it started at the 3rd gear, which I felt like it was really at the 1st gear, as it would not go over 20MPH even the RPM constantly hitting close to the red line. Ultimately, it also needed an automatic "bang" to bring itself back to normal state.

The dealer couldn't get a code, and couldn't duplicate the problem, but they replaced the entire transmission after I showed them 3 video clips of different occurrences, and that solved the problem completely. On the other hand, I was surprised that I was able to duplicate the problem on a '04 Cayenne S loaner that the dealer lent to me during the repair. I think it may not be uncommon.

ps. It first happened when switching down gears manually, but later problems occurred any time the vehicle as accelerated slightly faster, and it would not up or down shift even with Tip Tronic.

Edited March 27, 2009 by AlienGG

[hawkeye651]

Hi,

Similar fault on my UK Mar 2005 Cayenne S - 40,000m.

After numerous attempts to diagnose the fault I have managed to capture the following Fault Code on two separate occasions:-

Code P0021 - intake cam shaft adjustment bank 2 implausible signal.

Question - does this indicate a dodgy sensor and could this be the source of the fault?

Grateful for any thoughts.

Thanks

:)

[hawkeye651]

Anyone?

:(

[Loren]

Hi,

Similar fault on my UK Mar 2005 Cayenne S - 40,000m.

After numerous attempts to diagnose the fault I have managed to capture the following Fault Code on two separate occasions:-

Code P0021 - intake cam shaft adjustment bank 2 implausible signal.

Question - does this indicate a dodgy sensor and could this be the source of the fault?

Grateful for any thoughts.

Thanks

:)

P0021 Adjustment of Inlet Camshaft in relation to Crankshaft, Bank 2 – Signal Implausible

Possible cause of fault

- Dirt in oil circuit

- Sealing strips on inlet camshaft adjuster faulty

- Oil pressure too low

- Mechanical fault in inlet camshaft adjuster

- Magnetic hydraulic valve faulty

[hawkeye651]

Hi,

Similar fault on my UK Mar 2005 Cayenne S - 40,000m.

After numerous attempts to diagnose the fault I have managed to capture the following Fault Code on two separate occasions:-

Code P0021 - intake cam shaft adjustment bank 2 implausible signal.

Question - does this indicate a dodgy sensor and could this be the source of the fault?

Grateful for any thoughts.

Thanks

:)

P0021 Adjustment of Inlet Camshaft in relation to Crankshaft, Bank 2 – Signal Implausible

Possible cause of fault

- Dirt in oil circuit

- Sealing strips on inlet camshaft adjuster faulty

- Oil pressure too low

- Mechanical fault in inlet camshaft adjuster

- Magnetic hydraulic valve faulty

Many thanks Loren - will report back.

[hawkeye651]

Just had the cam sensor changed along with 8 ignition coils (all cracked!) and the symptoms appear to have gone for now.

:renntech:

[Guest]

do you have the part number for the cam sensor? I don't have that error on my car, but I consider change this sensor also cause I've seen it in other Cayenne S. it looks like this sensor is just another part that needs to be changed.

about the Backfires though Intake:

They are caused by a bad intake valve and thats it.

What can be done? You can probably get a valve job done, but thats beyond what I would do to my car now cause you have to take out your heads, etc...

I started to use Gasoline aditives, those that are specialy made to clean the valves and intake sistem. the result is good, not even a backfire since then. I used till now 2 botles and 200 liters of gas. :)

Hope this helps.

Ilie

Edited May 7, 2009 by stealthTT

[hawkeye651]

do you have the part number for the cam sensor? I don't have that error on my car, but I consider change this sensor also cause I've seen it in other Cayenne S. it looks like this sensor is just another part that needs to be changed.

about the Backfires though Intake:

They are caused by a bad intake valve and thats it.

What can be done? You can probably get a valve job done, but thats beyond what I would do to my car now cause you have to take out your heads, etc...

I started to use Gasoline aditives, those that are specialy made to clean the valves and intake sistem. the result is good, not even a backfire since then. I used till now 2 botles and 200 liters of gas. :)

Hope this helps.

Ilie

Apologies for the delay - just got the part no. from the garage - 948 105 303 06 described as 'Throttle Control Element'.

Seems to have done the trick for me. :D

[lporsche]

hi

i have the same error code too , but still couldn't correct it untill now, do you now if it can destroy the engine or other components , i had this error now for 4 months, and before this error came in the car shows that oil pressure too low couldn't start and after a while( a week) all was gone car start and i got this error, but those days was too cold to like -30 degre celcius , ik couldn't start the car since the temperature goes up but now car seems to runs good but still with that error , just this week i feel that the engine tremble a little bit sometimes so do you guys have an advice for me thanks

[darrinsmith]

Hi

I am also getting this error (P0021) repeatedly on my 2003 Turbo. It also seems to be accompanied by enging "harshness" around 3000-3500 rpm, which smooths out at higher rpm.

Is there a DIY for locating and replacing the sensor? I couldn't find one on the search.

I'd rather try that before unleashing the dealer on the car.

Thanks

Darrin Smith

[RFM]

Post #7

Take a look on this discussion to have a larger overview about P 0021.

[darrinsmith]

Thanks

The reason I suspect the sensor is that the problem is intermittant.

Thanks

DS