# 19 MPG, mildly low on power



## jab91 (Dec 11, 2011)

Hey guys,

Ive got a platinum grey 09 2.5l jetta. The odometer just turned over 65k last week. The car itself drives great. It seems to be mildly low on power under 3k rpm. however, I'm averaging 19mpg. Ive done plugs and the air filter and that made literally no difference at all. There is a faint intermittent tapping noise at the back right of the engine (when looking at it from the front). I'm 100% positive its not the valve train. I can hear that ticking too and it is a much different noise. the one I'm hearing is lower in tone. more of a hollow tap and less metallic sounding than the drive train noise. 

A few days ago I was running the car with the hood popped trying to get the tapping on video (its too faint to catch though, atleast with a cell phone). when I turned the car off there was a hissing noise coming from the same area as the tapping. sounds almost like something depressurizing. 

long story short here's the video:

disclaimer: No, I don't run that cone filter. I threw it on to hopefully hear the engine a little bit better than you can with the stock engine cover.

Any idea's on what could be wrong?


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## dhenry (Feb 10, 2009)

the hissing noise is normal mine always does that i just hit 65k and did an 6 hr drive back and forth to raleigh NC no issues 1 tank of gas roughly 35mpg hwy . its also a 2009 keep up with the maintenance it will take you far


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## thygreyt (Jun 7, 2009)

the pic is from today. 68k, and i get VERY good milage, no weird sounds to report either.

Maintenance: oil change (lubro moly 5w-40) every 5k, rotation every 2k, 20k services done at 15k intervals and 40k services done at 35k intervals.

i replace EVERY bolt as instructed by the bentley manual, and i am anal about the car... lol.


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## dhenry (Feb 10, 2009)

thygreyt said:


> Maintenance: oil change (lubro moly 5w-40) every 5k, rotation every 2k, 20k services done at 15k intervals and 40k services done at 35k intervals.


^ya this guy has got the right idea.:thumbup:
i like using lubro moly oil.

also maybe that clicking tapping noise is something like the valvetrain lifters and my car also makes that noise. nothing to worry about


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## jaja123 (Jan 17, 2011)

the 2.5 is always low on power


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## stupakjim (Sep 17, 2005)

Maybe you got a vacuum leak????


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## 08VWDUB (Feb 1, 2012)

*Bad Gas?*

What octane gas are you useing?

Even though the car does not require it,it has been proven these engines make more power on higher octane gas? 

http://www.europeancarweb.com/tech/proven/epcp_1007_2010_volkwagen_jetta_proven/index.html

Run a tank of 93 and see what happens

Do you have the six speed auto? If so,running trough the first three gears from a dead stop sometimes the car can feel kind of sluggish,if your going easy on throttle.If you want to take off faster maybe try sport mode.


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## nothing-leaves-stock (Mar 1, 2005)

jaja123 said:


> the 2.5 is always low on power


haha TRUTH! oh well.
may have a fueling issue....02 sensor?
did it just change? or was it always like this?


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## LampyB (Apr 2, 2007)

sounds like you have a boost leak if you're not seeing a CEL. if you've been playing around with the intake double check your hose connections as a first step. then take it in to have a pressure test done on the system to check for leaks.

does the guy who posted his dashboard above have an automatic or manual tranny? if i drive like an old woman i may get close to this mileage, but normally i'm at 200 miles to the tank by the time i hit half way to empty. sometimes even around 185 miles if i've been heavier on the throttle. i live at sea level, have new plugs and coils as well, no air leaks, and a 5spd manual.


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## dhenry (Feb 10, 2009)

LampyB said:


> sounds like you have a boost leak if you're not seeing a CEL. if you've been playing around with the intake double check your hose connections as a first step. then take it in to have a pressure test done on the system to check for leaks.
> 
> does the guy who posted his dashboard above have an automatic or manual tranny? if i drive like an old woman i may get close to this mileage, but normally i'm at 200 miles to the tank by the time i hit half way to empty. sometimes even around 185 miles if i've been heavier on the throttle. i live at sea level, have new plugs and coils as well, no air leaks, and a 5spd manual.


that guy is cheating. he has a 6 speed swap. 
but i am also just like yours. sea level and i hit 200 at the halfway. but it falls rapidly after that. ~350-375 miles a tank. 70% stop and go traffic. and SRI + UM tune = heavy foot:laugh:


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## thygreyt (Jun 7, 2009)

LampyB said:


> sounds like you have a *Vacuum* leak if you're not seeing a CEL. if you've been playing around with the intake double check your hose connections as a first step. then take it in to have a pressure test done on the system to check for leaks.
> 
> does the guy who posted his dashboard above have an automatic or manual tranny? if i drive like an old woman i may get close to this mileage, but normally i'm at 200 miles to the tank by the time i hit half way to empty. sometimes even around 185 miles if i've been heavier on the throttle. i live at sea level, have new plugs and coils as well, no air leaks, and a 5spd manual.


me?
i have a jetta 2.5L with a 6spd Manual (02Q). i dont drive like an old woman, nor slow either. i'm just not trying to live life 1/4 mile at a time.

i just drive a LOT, so i dont find it very fun to waste gas. But i dont hypermile either... just driving like a regular/normal citizen. I also have had 2 tickets in the last 2 months (both were for 9 over the limit) so i HAVE to drive like a regular citizen or i'll lose my license.

I am also at sea level, Florida.

right now, i'm at 1/4 tank left, and 320 miles on the odo.


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## stupakjim (Sep 17, 2005)

You could check the pcv valve, maybe the diaphram is ripped?


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## jab91 (Dec 11, 2011)

I've had the car for about 2 months now and its been this way since I got it. I started out with a mk3 GTI 2.slow than went into an 01 bmw 325xi (that I was T-boned in, which is why i moved into the jetta). So I'm no stranger to preventative and routine maintenance. I just have to believe that there is something faulty in my engine since im getting 19 mpg. I'm lucky if I get 280 miles per tank and when people with my exact setup are getting 350 plus it kind of makes me worry a little bit. The car itself drives fine; no real hesitation or anything making it seem like something is obviously broken. It just doesn't feel quite right

I noticed when I did the plugs that the coils had spots of brown staining on them almost like rust. could it be the coils? The car runs slightly rough at idle. feels almost like a misfire but isnt consistent enough to make me think its misfiring. the Idle also stays almost perfectly at 700. no jumping or spiking at all.

It's also not throwing any codes. I scan my cars at least once a month to make sure the CEL/SES hasnt burned out in the dash.


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## DerekH (Sep 4, 2010)

jab91 said:


> The car runs slightly rough at idle. feels almost like a misfire but isnt consistent enough to make me think its misfiring. the Idle also stays almost perfectly at 700. no jumping or spiking at all.


This is pretty normal, most of us have this issue. coils really should be done at the same time the spark plugs are done. If the car isn't throwing any codes it is likely a filter, either fuel or air would be my guess.


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## stupakjim (Sep 17, 2005)

"slightly rought at idle", try replacing the purge valve ([email protected]), just went through this with my 2.5, was getting bad mpg's, replaced fuel filter, plugs, and coils, wasnt until I replaced that valve that the car ran like wwwwwaaaayyyy better.


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## jaso028 (Aug 12, 2007)

Have you done a fuel filter yet?


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## jab91 (Dec 11, 2011)

Ive done the Fuel filter and the purge valve. a few days ago I pulled my coils off and found this: 














































could this be the culprit? what exactly is happening here and how would I go about fixing this? it looks like rust but chips off like it's dried on molasses or something along those lines.


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## jab91 (Dec 11, 2011)

There is also a strong scent of fuel in the intake manifold, which I'm assuming is generally not a good sign?


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## Zoolook_ (Mar 17, 2012)

08VWDUB said:


> What octane gas are you useing?
> 
> Even though the car does not require it,it has been proven these engines make more power on higher octane gas?
> 
> ...


 I have read in so many places that this is a myth, but I really don't know. I am going on a very long road trip next week (about 1800 miles round trip) so I am going to test it for myself. I have a 2.5l Golf (2011). I'll post results here.


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## thygreyt (Jun 7, 2009)

do 3 tanks if each fuel. 

try to use shell.


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