# VW Specialist can't fix my car. EPC light and Chain Rattle when warm.



## BeavisGolf (Jan 1, 2003)

Hi guys, had my car at an Audi/VW specialist for the last 2 weeks and they have come back to me and said they can't fix it. Hoping someone on here could give me some pointers.

Car is late 2009 MK6 GTI

Bit of background. 

Driving the car. Idle is fine, when you accelerate there is a hesitation at 2000rpm, EPC light flashes, Audible chime and "Engine Fault - Workshop" appears on the MFA Revs drop and error goes away. Accelerate again and same issue. Also the Engine is rattling. 

Got the car on a scanner

Code 16725/P0341/000833 - Camshaft Position Sensor (G40): Implausible Signal

So check the wiring to to the cam sensor and when I unplugged it the rattle noise appeared louder. I ran a live scan on the output from the cam sensor and it runs fine and breaks down at 2000rpm when the fault appears. Goes to 0

Having read about the potential tensioner issue on these cars I decided no to start the car and got it towed to a specialist to have the new tensioner installed and timing checked. 

So the garage installed a new tensioner and checked the timing (timing chain was well in spec) and put a new cam sensor in.

Car still behaving the same as before.

Garage then installed a new oil spool valve, magnetic cam actuator and cam bridge (cam bridge screen was damaged)

Now the car runs perfect till normal operating temps are reached and then the rattle starts (sounds like cam chain rattle) and you get the EPC light come on when off throttle. Acceleration is fine.

If you unplug the magnetic cam actuator the engine has no rattles it drives fine and revs with no errors. 

Garage send a message saying "we can't do anymore, take it to VW"

Anyone got any ideas? 

Could it be the VVT Cam not working properly
Oil pressure low in the cam due to cam bridge screen damage
Chain stretched??????
Electrical - Cam sensor wiring, Crank sensor etc.

Really at a loss

TL: DR - EPC Light comes on when off throttle after accelerating, engine rattles like chain slap but timing chain is not stretched and car has a new chain tensioner.

Cheers
Chris


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## ROH ECHT (Dec 9, 2010)

Wait...you had the P0341 code and all that was done was "check the wiring" and the G40 was replaced. The other possibility is the timing is off between cams so chain may have skipped. But you said wiring to the G40 and timing is good and now you do not get any codes? Having the MFD warning should store a code.

Have you replaced the N205? I didn't see it mentioned...I only see


> a new tensioner and checked the timing, new G40 sensor, oil spool valve, magnetic cam actuator and cam bridge


Something is off and again, there are no codes, correct? It's a feeling of a "hesitation", skip or momentary pause in smoothness and power with the MFD warning...seems like it still has a intermittent power issue to a sensor for the VVT system.


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## BeavisGolf (Jan 1, 2003)

ROH ECHT said:


> Wait...you had the P0341 code and all that was done was "check the wiring" and the G40 was replaced. The other possibility is the timing is off between cams so chain may have skipped. But you said wiring to the G40 and timing is good and now you do not get any codes? Having the MFD warning should store a code.
> 
> Have you replaced the N205? I didn't see it mentioned...I only see
> 
> Something is off and again, there are no codes, correct? It's a feeling of a "hesitation", skip or momentary pause in smoothness and power with the MFD warning...seems like it still has a intermittent power issue to a sensor for the VVT system.


Hi there. Sorry for the delay. Things got away from me. 

So over the weekend I replaced the following

Timing Chain
N205
Tensioner
Intake Cam
Magnetic actuator
Cam bridge
Cam sensor

Car is not throwing the MDF message but the chain rattle is still there. No hesitation just loud rattle at 2.5k rpm and 4.5k rpm. And rattles when off throttle from high revs. 

I'm thinking it's oil starvation to the VVT. Going to drop the sump and check the oil pickup. 

Sent from my SM-G955F using Tapatalk


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## kjr6306 (Sep 12, 2007)

If you are going to drop the pan look at the oil pump chain, sprockets and tensioner. Also, remove the pickup tube and thoroughly clean the screen.


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## Fleitipon (Oct 24, 2018)

Hey man. I have an Audi A4 2011 2.0t. Same engine as yours. I’m having the same issue. But for me the car does the same thing as yours maybe around 1000 rpm. If you try to go really slow. But if you press the gas pretty quick it doesn’t happens. And I get the p0341 code. I replace the magnetic adjuster. The the plunger underneath, chain, chain tensioner, guides and sensor. All those parts I bought it from the dealership. And I’m still having the same issue. The car runs fine mostly. But that’s the only problem that I am having.


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## Kilanski (Nov 1, 2018)

*a bit tricky*

you either have a problem with oil pressure

or you need a new camshaft!


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## LB25 (Mar 14, 2019)

Any updates? I am having this problem currently with my 2010 Audi A4. Chain tensioner replaced by mechanic, still receiving EPC and engine light after driving for a bit when rpms get low and am not accelerating quickly/are at higher rpms. Cam shaft then replaced. Started to drive home and same issue about 20 miles later when I got off highway and slowed down


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## Thy_Harrowing (Dec 7, 2014)

LB25 said:


> Any updates? I am having this problem currently with my 2010 Audi A4. Chain tensioner replaced by mechanic, still receiving EPC and engine light after driving for a bit when rpms get low and am not accelerating quickly/are at higher rpms. Cam shaft then replaced. Started to drive home and same issue about 20 miles later when I got off highway and slowed down


Like the guy above you said to the guy having the same issue... if you have replaced all the same parts the OP replaced then the likely source of the issue is an oil pressure issue because the tensioning of the cam chain is variably adjusted based on oil pressure. Check oil pressure. Should be something like 17-30psi at idle at NOT (normal operating temp) and 39-65psi at 2K RPMs at NOT. If oil pressure is low oil pump may be failing or you have blockage at the oil pickup tube (screen) to the oil pan.


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## alloutwar1 (Apr 8, 2009)

Sounds like your vw specialist isnt a vw specialist..... You can watch the variable valve timing live on a scanner. You can watch it retard and advance when you give it throttle or cruise around town. You can also use a scope to watch the pattern of the camshaft compared to the crankshaft.

Also too the new timing chain tensioner comes equipped with a spring so the hydrualic part of the timing chain tensioner cant compress it stays in a locked position incase of oil starvation.

Think you need someone that understands a scanner


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## silver06passat (Dec 12, 2011)

Our car did this a while ago...very carefully and completely check the rings on the VVT "tower"? inside the cam chain cover. if they are okay, you must further check the grooves that those rings sit in. if they are out of square or worn, the rings will not operate properly. This drove me crazy for quite a while. I carefully drove the car back from our mechanic who gave up too.....and then tore it all apart myself and carefully checked every nook and cranny...which is when I found the issue. 

I also put an oil pressure gauge in the car that I ran off the oil filter housing. works great. peace of mind, you know? Oil pressure does come from the health of the bearings among other things.....

good luck with those cars, guys. 


JP


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## GTI's (Nov 27, 2011)

silver06passat said:


> ........................... inside the cam chain cover. if they are okay, you must further check the grooves that those rings sit in. if they are out of square or worn, the rings will not operate properly...........................
> 
> 
> JP


The CA has a smooth bore from the manufacture, it is not grooved to seat the rings. What you are seeing is wear.


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## Spl28 (Apr 15, 2021)

BeavisGolf said:


> Hi guys, had my car at an Audi/VW specialist for the last 2 weeks and they have come back to me and said they can't fix it. Hoping someone on here could give me some pointers.
> 
> Car is late 2009 MK6 GTI
> 
> ...


Hi, Did you finally get is sorted? I am having the same problem, i don't want to spend much on unnecessary parts. 

Thnks, cheers..


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## ROH ECHT (Dec 9, 2010)

GTI's said:


> The CA has a smooth bore from the manufacture, it is not grooved to seat the rings. What you are seeing is wear.


I received a notification for this today....I read the post you quoted and; facepalmed myself.


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## Brandonrag (Oct 11, 2021)

Fleitipon said:


> Hey man. I have an Audi A4 2011 2.0t. Same engine as yours. I’m having the same issue. But for me the car does the same thing as yours maybe around 1000 rpm. If you try to go really slow. But if you press the gas pretty quick it doesn’t happens. And I get the p0341 code. I replace the magnetic adjuster. The the plunger underneath, chain, chain tensioner, guides and sensor. All those parts I bought it from the dealership. And I’m still having the same issue. The car runs fine mostly. But that’s the only problem that I am having.


Did you find the problem?


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## ROH ECHT (Dec 9, 2010)

The OP's engine is EA888/TSI. So its cam adjuster/phaser differs from the EA113 in that it has no replaceable rings. It's adjuster threads into the cam phaser and spins with it. Its internal valve is opened and closed magnetically. They've said all is running fine, no more codes, except for the loud rattle noise. 

Ways the EA888 cam adjusting fails I have seen recently:
Sometimes the alignment pin shears off between the 'adjuster unit/cam phaser' and the intake cam.
Poor oil pressure/flow.
More often, EA888 folks are finding the pick-up screen is blown out or completely dislodges and falls off. The OPs was found damaged, and the codes appeared no more after the cam bridge was replaced.
...this one shows the screen blown out;









...this one shows both the screen on and one which has fallen off;


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