# Lack of power/Slow acceleration times - '08 Passat Variant 2.0t



## Storm_Shadow (Apr 7, 2012)

*[SOLVED] Lack of power/Slow acceleration times - '08 Passat Variant 2.0t*

Hello. 

I have a '08 2.0t Passat Variant (~ 45k miles) which is going through a severe lack of power under all loads. The 0-60mph times, for instance, which were completed at around 8 seconds, can't get done under 11 seconds now. 

I took it to a repair center, where It had all its spark plugs and the pressure regulator valve replaced. I talked to the guys about my issues, but they had the car checked with the VAG and nothing abnormal has come up from it. 

The problem still remains after the service has been done. 

Do you guys have some hint of what may be causing this issue? Apart from the lack of power, the engine seems to be running smooth. Could it be a faulty turbo? 

Thanks! 

Specs: 

'08 Passat Variant 
2.0t engine 
Six-speed Automatic Transmission 
Front Wheel Drive


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## TCFGLI08 (Apr 6, 2011)

Are you boosting? Do you have a boost gauge?


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## Storm_Shadow (Apr 7, 2012)

TCFGLI08 said:


> Are you boosting? Do you have a boost gauge?


 Thanks for your reply. 

Right now I don't, but I can get one. What values should I read? Is there any reference graph of boost vs rpm? 

I was reading about the diverter valve yielding boost loss. Is a faulty DV necessarily related to a fault code in VAG? 

Thanks again.


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## Krieger (May 5, 2009)

check cam follower, check PCV, check, check DV, check for leaks. 

if its idling fine, PCV is prob fine, and there shouldnt be a leak... so id lean more towards a faulty DV. 

go on APR's site and look for how to run logs. should be in their support section i think... measure boost, fuel, timing, n75.


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## Storm_Shadow (Apr 7, 2012)

Thanks, pal. 

I will try to figure it out and then come back here with an answer (hopefully). 

Regards.


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## Storm_Shadow (Apr 7, 2012)

*No luck so far...*

Here's the sitrep: 

I've had both the DV and cam follower replaced (bought at ECS). It's got a little better, but it's still far from what it was. The cam follower was not worn out, but I replaced it anyway. The old DV shows no cracks nor any other visible defect, but its connector was showing some oil contamination. It was the old model one, not the D variant. I will take some pics of it to show its actual condition. 

Now the 0-62mph is accomplished in around 10 seconds, as opposed to the 11 seconds before these replacements. I used to get around 8 seconds at that test. 

Summing what I've replaced so far: 

PCV; 
cam follower; 
Diverter Valve. 

Regards.


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## Krieger (May 5, 2009)

ever replace fuel filter?


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## Storm_Shadow (Apr 7, 2012)

Krieger said:


> ever replace fuel filter?


 No, I haven't. I remember feeling strange when the technical consultant at the repair shop said that the 2.0T didn't have the need to have its fuel filter replaced... 

Is there any guide on how to change it, like location and codes of related parts? 

Could my problem be a bad MAF? 

Thanks for your replies.


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## Krieger (May 5, 2009)

google the filter or do a search... pics are floating around. 

as to the MAF, unplug it and see if it feels better.


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## Storm_Shadow (Apr 7, 2012)

I found this code for the filter: 1K0 201 051K. It's made for the Golf and the A3, though. 

It seems that the Passat's filter is inside the fuel tank... I haven't found on Google nobody that has changed it. EDIT: It seems that there are some parts related to the filter, but I see no one going further in this regard: 

http://forums.vwvortex.com/showthread.php?5282243-Passat-2006-2.0L-FSI-Fuel-filter 

I'll try your suggestion regarding the MAF. 

Thanks.


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## HillRoad1 (Nov 20, 2008)

Fuel filter in passat are part of electrical fuel pump inside gas tank.


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## Storm_Shadow (Apr 7, 2012)

*Sitrep*

Here's what I've done so far:

My mechanic has identified some carbon on the intake valves. He's used a valve cleaner fluid, but he said it takes some time in order to get the valve rid of it completely. If that doesn't solve the carbon build up on the valve, then they will have to remove the cylinder head altogether in order to clean all valves manually.

In the meantime, I've noticed that its idle has some strange vibrations from time to time. Just like misfires, but the VAG doesn't read any. I've found that my symptoms are quite similar to these: 

http://forums.vwvortex.com/showthre...le...HELP!&p=47410042&viewfull=1#post47410042

I've noticed that the most noticeable lack of power is when I change gears, when the engine RPM's fall from around 6k to around 4k. This is also limiting my top speed when climbing, because the engine won't build up revs from 4k onwards.

I still haven't run it with the MAF unplugged, but I will do it ASAP.

I was leaning towards a faulty injector, but I don't know how to identify this kind of failure. Any tips? The VAG readings are all normal, according to the mechanic.

PS: 
ENGINE CODE: BWA (perhaps it's the TFSI - it runs a timing chain, not timing belt)
Spark plugs: are relatively new (less than 5k miles)
PCV: new
DV: new
Cam FolloweR: new
No misfire in VAG readings.


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## Storm_Shadow (Apr 7, 2012)

*Update*

Unplugging the MAF has not helped in any way. The car still has sudden vibrations in idle and the performance is still crappy. I have never had a single engine light coming on.

Any clues, guys?

Could this all be due to those carbon build ups on the admission valves? Perhaps a clogged injector? How to detect one?

Thanks again!


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## SCIROCCO SPEED (Dec 6, 2002)

with only 45k miles, i wouldn't think the carbon build up on the valves (yes it's a well known problem) would cause the severity of your issues. Even if it is, the cylinder head doesn't need to be removed, only the intake manifold.

I would definitely try to find out what your boost pressure is thru the RPM range. You can easily install a temporary gauge if you don't want to have one permanently in the dash.

or, even better...

If your mechanic does in fact have VagCom software (and assuming it's on a laptop), i suggest the two of you go on a test drive and log the values for boost (specified and actual), timing, and fuel pressure, and rail pressure. You will need to find an open stretch of road with very little to no traffic to properly run the log, as you will need to be in 3rd or 4th gear and start at 1,500 RPMs and go wide open throttle until 6,000 RPM. 

Good luck and let us know your findings.

Performing a throttle body adaptation with the software might not hurt either.


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## Storm_Shadow (Apr 7, 2012)

*Update:*

I've had its intake manifold removed and to my surprise the carbon build up is minimum (see attached picture - the intake wall seem black on the pic, but it's actually as clean as the valves - that is due to the camera flash) ... I've used two bottles of AG2000 VW official fuel system cleaner (50 litre of fuel per bottle) to get at least the injectors cleaned and the benefit was unfelt, at minimum. 

My mechanic has attached a boost gauge to the car and we gave it an open throttle run on the highway. *It isn't topping even 0,5 bar*... *The actual sustained boost at maximum throttle aperture is only 0,35 to 0,4 bar*. 

I've read that the stock values should be: 

1,0 bar (peak) and 0,7 bar (sustained boost). Remember I have a brand new DV from ECS. 

I've taken it to a VW dealer where they've checked it for leaks and both the dealer and my mechanic say it has none. I've also asked for the dealer to do a throttle body adaptation and the situation remains the same. 

The VAS system from the dealership hasn't detected any fault code. 

I suspect that there was a misread value from one or more sensors that would cause the ECU to cut the boost or limit the fuel injection, but according to my mechanic he already had the system plugged in with the car running and there were no fault codes nor abnormal values read. His system isn't capable of logging, though. 

I am really losing any left hopes of solving this puzzle... 

Anyway, thanks for all contributors... I will update this thread with new info as soon as get them.


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## Storm_Shadow (Apr 7, 2012)

*GREAT NEWS!* 

My mechanic has found it! The MAP was misreading the pressure values! 038906051D is the code for the part that was changed. 

Now the engine is revin' like a mad dog! Lots of wheel spin @ full thottle in 1st gear, which wasn't happening before. I've tested it on the highway and it's fabulous now! 

Here in Brazil we have a gasoline called Petrobras Podium, which is a 95 octane fuel. I've filled the tank with it and gave it a second run. It's really alive now. 

I still have a slightly rough idle, though... Do you now what could be producing it? 

Thanks for all of you that have read this thread and have added some valuable comments to it.


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