Cayenne 957 Turbo Starting Issues
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Joined: Mar 2022
Posts: 14
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From: UK
Cayenne 957 Turbo Starting Issues
Hi,
I recently purchased my first Cayenne from auction - it's a 2008 4.8L Turbo. The car has some minor issues due to age, but I know what to expect after 10 years of owning and self-maintaining various Audi A8s.
The main issue that I would like to resolve is a starting problem. When I first purchased the car, it was very difficult to start. When turning the key, the car would crank, "almost" fire up, and then immediately cut out. It would take up to 20 minutes of turning the key back and forwards to finally start the car - sometimes the battery would drain before it started!
I know that it's not uncommon for starter motors to fail with similar symptoms on these cars, so I replaced it and fitted a new battery as a precaution. Unfortunately, this didn't improve things.
I scanned the car for codes and it returned P0016 (Camshaft Sensor Bank 1 G40 / Engine Speed Sensor G28 - Incorrect Correlation). To diagnose this further, I unplugged the camshaft sensor on cylinder bank 1 and tried to start it again. This helped massively - it now starts after 2 or 3 attempts every time. I purchased a pair of replacement Bosch camshaft sensors to see if this cured the issue. After fitting the new sensors tonight, the car no longer starts with the same symptoms as before. I have now unplugged the sensor on bank #1 again which allows me to start it.
I'm going to look at the crankshaft sensor next. The common causes for P0016 seem to be camshaft sensors, crankshaft sensor, stretched cam chain, or faulty VVT solenoids. Since the car runs fine when it does eventually start, I'm assuming it's not due to a stretched chain. Also, the fact that it starts much easier when the camshaft sensor is unplugged suggests an electrical issue to me.
Has anybody had similar issues before? I can't find much online about this - starter motors are generally the issue from what I can see.
Thanks
I recently purchased my first Cayenne from auction - it's a 2008 4.8L Turbo. The car has some minor issues due to age, but I know what to expect after 10 years of owning and self-maintaining various Audi A8s.
The main issue that I would like to resolve is a starting problem. When I first purchased the car, it was very difficult to start. When turning the key, the car would crank, "almost" fire up, and then immediately cut out. It would take up to 20 minutes of turning the key back and forwards to finally start the car - sometimes the battery would drain before it started!
I know that it's not uncommon for starter motors to fail with similar symptoms on these cars, so I replaced it and fitted a new battery as a precaution. Unfortunately, this didn't improve things.
I scanned the car for codes and it returned P0016 (Camshaft Sensor Bank 1 G40 / Engine Speed Sensor G28 - Incorrect Correlation). To diagnose this further, I unplugged the camshaft sensor on cylinder bank 1 and tried to start it again. This helped massively - it now starts after 2 or 3 attempts every time. I purchased a pair of replacement Bosch camshaft sensors to see if this cured the issue. After fitting the new sensors tonight, the car no longer starts with the same symptoms as before. I have now unplugged the sensor on bank #1 again which allows me to start it.
I'm going to look at the crankshaft sensor next. The common causes for P0016 seem to be camshaft sensors, crankshaft sensor, stretched cam chain, or faulty VVT solenoids. Since the car runs fine when it does eventually start, I'm assuming it's not due to a stretched chain. Also, the fact that it starts much easier when the camshaft sensor is unplugged suggests an electrical issue to me.
Has anybody had similar issues before? I can't find much online about this - starter motors are generally the issue from what I can see.
Thanks
RL Community Team
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Joined: Oct 2007
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From: Clemson, SC
A starter motor either engages and turns the motor or it doesn't. If your car cranks for 20 minutes, it's not the starter motor, or at least it wasn't originally, but may be now if you tried to run the starter motor so much that it killed the huge H9 battery.
I would say replace the crankshaft position sensor. Does the tach needle bounce a little when you're cranking the engine with the starter? It should as the Crank position sensor detects the rotation.
I would say replace the crankshaft position sensor. Does the tach needle bounce a little when you're cranking the engine with the starter? It should as the Crank position sensor detects the rotation.
Track Day
Joined: Jul 2024
Posts: 15
Likes: 2
Hi,
I recently purchased my first Cayenne from auction - it's a 2008 4.8L Turbo. The car has some minor issues due to age, but I know what to expect after 10 years of owning and self-maintaining various Audi A8s.
The main issue that I would like to resolve is a starting problem. When I first purchased the car, it was very difficult to start. When turning the key, the car would crank, "almost" fire up, and then immediately cut out. It would take up to 20 minutes of turning the key back and forwards to finally start the car - sometimes the battery would drain before it started!
I know that it's not uncommon for starter motors to fail with similar symptoms on these cars, so I replaced it and fitted a new battery as a precaution. Unfortunately, this didn't improve things.
I scanned the car for codes and it returned P0016 (Camshaft Sensor Bank 1 G40 / Engine Speed Sensor G28 - Incorrect Correlation). To diagnose this further, I unplugged the camshaft sensor on cylinder bank 1 and tried to start it again. This helped massively - it now starts after 2 or 3 attempts every time. I purchased a pair of replacement Bosch camshaft sensors to see if this cured the issue. After fitting the new sensors tonight, the car no longer starts with the same symptoms as before. I have now unplugged the sensor on bank #1 again which allows me to start it.
I'm going to look at the crankshaft sensor next. The common causes for P0016 seem to be camshaft sensors, crankshaft sensor, stretched cam chain, or faulty VVT solenoids. Since the car runs fine when it does eventually start, I'm assuming it's not due to a stretched chain. Also, the fact that it starts much easier when the camshaft sensor is unplugged suggests an electrical issue to me.
Has anybody had similar issues before? I can't find much online about this - starter motors are generally the issue from what I can see.
Thanks
I recently purchased my first Cayenne from auction - it's a 2008 4.8L Turbo. The car has some minor issues due to age, but I know what to expect after 10 years of owning and self-maintaining various Audi A8s.
The main issue that I would like to resolve is a starting problem. When I first purchased the car, it was very difficult to start. When turning the key, the car would crank, "almost" fire up, and then immediately cut out. It would take up to 20 minutes of turning the key back and forwards to finally start the car - sometimes the battery would drain before it started!
I know that it's not uncommon for starter motors to fail with similar symptoms on these cars, so I replaced it and fitted a new battery as a precaution. Unfortunately, this didn't improve things.
I scanned the car for codes and it returned P0016 (Camshaft Sensor Bank 1 G40 / Engine Speed Sensor G28 - Incorrect Correlation). To diagnose this further, I unplugged the camshaft sensor on cylinder bank 1 and tried to start it again. This helped massively - it now starts after 2 or 3 attempts every time. I purchased a pair of replacement Bosch camshaft sensors to see if this cured the issue. After fitting the new sensors tonight, the car no longer starts with the same symptoms as before. I have now unplugged the sensor on bank #1 again which allows me to start it.
I'm going to look at the crankshaft sensor next. The common causes for P0016 seem to be camshaft sensors, crankshaft sensor, stretched cam chain, or faulty VVT solenoids. Since the car runs fine when it does eventually start, I'm assuming it's not due to a stretched chain. Also, the fact that it starts much easier when the camshaft sensor is unplugged suggests an electrical issue to me.
Has anybody had similar issues before? I can't find much online about this - starter motors are generally the issue from what I can see.
Thanks
I have the exact same issue as you described. Did you ever solve it? Was it the chain?
Thread Starter
AutoX
Joined: Mar 2022
Posts: 14
Likes: 5
From: UK
I bought the special camshaft alignment tool on eBay and re-aligned it myself, I didn't replace any other parts. The job wasn't too difficult in the end, the hardest bit was reaching some of the rear bolts on the valve covers.
The car gained a significant amount of power after completing the job, and the camshaft deviation values stayed within range (almost perfect after my re-alignment) until I sold the car 12 months later.
I have received several messages about this issue in recent months, it seems to be becoming a very common issues on 4.8L 957s at this age.
3rd Gear
Joined: Dec 2024
Posts: 3
Likes: 1
Hi. Yes, it was the chain alignment, you can easily confirm this if you have a scanner (eg iCarSoft). Check the camshaft deviation values - one of the banks will probably be >10deg out of range.
I bought the special camshaft alignment tool on eBay and re-aligned it myself, I didn't replace any other parts. The job wasn't too difficult in the end, the hardest bit was reaching some of the rear bolts on the valve covers.
The car gained a significant amount of power after completing the job, and the camshaft deviation values stayed within range (almost perfect after my re-alignment) until I sold the car 12 months later.
I have received several messages about this issue in recent months, it seems to be becoming a very common issues on 4.8L 957s at this age.
I bought the special camshaft alignment tool on eBay and re-aligned it myself, I didn't replace any other parts. The job wasn't too difficult in the end, the hardest bit was reaching some of the rear bolts on the valve covers.
The car gained a significant amount of power after completing the job, and the camshaft deviation values stayed within range (almost perfect after my re-alignment) until I sold the car 12 months later.
I have received several messages about this issue in recent months, it seems to be becoming a very common issues on 4.8L 957s at this age.
Can you explain how you did "retime" procedure? Im doing it right now and tools fit perfecly, but when I turn around the engine by hand bank 1 intake cam is off again.
