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Need help with intermittent loss of power!

MattyGTi

Ready to race!
okay so im guessing my car has a boost leak.

the turbo spools loudly when i get on the gas now and there is no more pull whatsoever...

i look at every connection there is nothing loose..vacuum lines are intact and so is the charge piping....i removed my forge dv spacer and reinstalled it and nothing...same issue...

it comes and goes too...like at times the power comes back out of nowhere full on and you get pushed in ur seat like u should...

then it goes back to spooling loudly and going nowhere


help!
 
P

plac

Guest
just because the charge piping is tight doesnt mean an o-ring isnt broken. although i never heard of that issue ever.
 

Mr.Alex

I Got That 6.
Could be a fuel pump, althought I think that would stall your car, maybe the fuel filter also. Try checking your MAF sensor.

Do you have the machine to see what codes pop up?
 

kennega

Ready to race!
Scan it with a VAG-COM. A large post-turbo leak like that will throw a code, but likely not a CEL. Check hoses and clamps going to/from the intercooler, as well as the throttle body. That is not a small leak if you are at full spool and going nowhere. Do you have a boost gauge?
 

Mr.Alex

I Got That 6.
Could also be a thrust sensor maybe.

When you rev it and go nowhere does your exhast king of like backfire and then you go again?
 

MattyGTi

Ready to race!
nah it doesnt backfire...

i do notice that its running rich cause im eatin gas like a 1986 dodge pickup

it kinda of makes a harmonic whistling sound *like blowing into the top of a soda bottle* when on full boost.

what i dont understand is why does it come and go....like it can be a whole day with no power then the next day it comes alive

im just gunna take the intake n dv spacer off n go to VW...let them worry about it...

but im sure they will give me the runaround and the 'cannot reproduce customer complaint' line of bullshit.
 

Mr.Alex

I Got That 6.
Could be a sensor, it blocks go and then the sensor kicks in and you go.
 

Q822

Ready to race!
My brother just had this trouble on his 09 GLI and it was the Boost gauge which was a lil unpluged. Do you have one?
 

MattyGTi

Ready to race!
nah i dont
 

Ryan Mills

Ready to race!
matty, check the fitting at the bottom of the turbo discharge pipe to the intercooler hose. Those buggers have been known to pop right the fuck off. -that's exactly why I got the AWE discharge pipe with ou that pesky fitting!!
 
P

plac

Guest
matty, check the fitting at the bottom of the turbo discharge pipe to the intercooler hose. Those buggers have been known to pop right the fuck off. -that's exactly why I got the AWE discharge pipe with ou that pesky fitting!!

just had to find a post with ryan in it.. dude, remind me why you ended up not liking your 335i again? im on a car hunt soon.. PM if you dont wanna wreck the thread topic..
 

callmec

Passed Driver's Ed
I have had the same issue for a long time and ready to give up on this car. Nobody know what's wrong with it. It's just like you said, it runs like crap and uses a lot of fuel and goes nowhere. But then some days out of nowhere its back to normal, accelerating smoothly and fast. Boost Guage show I'm peaking 15 psi which is good for APR stage 2. Did you ever figure out what was wrong?
 

bmahon

Passed Driver's Ed
Yeah I wish we could get an answer to this, I have a 2014 GTI with 12k miles and on random days it feels as if there is a noticeable difference in power.

Some days Ill get some huge boost sending me into the seat and making me so happy to feel torque then other days with my foot on the gas I feel like any other random car. I have written it off as hot summer temperatures, me getting used to the car's torque, not allowing the turbo to spool, or being shitty at driving a manual and shifting to 2nd too late. But it just always bugs me and I cant decide if this is normal or not.
 

TheCastle

Ready to race!
So just having seen these problems 1st hand....

If you have a boost leak it won't necessarily throw a check engine light. Vag com it or go to autozone and pull the ecu codes to see if you have any codes that could indicate a problem. If you have vag com log boost requested, boost actual, n75 duty cycle, rpms, lambda.

If you have a boost leak that is fairly bad, you will see n75 pegged near or at 100% and Actual boost not making requested boost.

So, most common leak points on this car are a blown oring at the top to intercooler coupler.

Next is a blown diverter valve and/or a blown pcv. Yes, the pcv on these cars fail a lot more often than people think. They just don't fail catastrophically like the fsi.

So running really rich, is a symptom of a big boost leak, along with the noise. Cars maf is reading lots of air going in, but it's leaking out before it enters the engine. I had that exact issue when I replaced my pcv and the intake manifold hose blew off that was connected to the pcv, causing a big boost leak.

Check your diverter valve and pcv. If one is blown I might suggest replacing both.

Also do a boost leak test, it will help you locate the problem
 
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