should I hear my turbo??

herbie lives

Well-known member
Joined
Jun 26, 2012
Location
el psao texas
TDI
2003 beetle TDI ALH
I just bought my 2003 beetle tdi about 2 months ago..It has 146thou on motor but seems to run fine ..Ofcourse I dont have anything to compare it to so im not sure the turbo is working to full boost because i dont ever hear it..Is this normal? Maybe I need to install a boost gauge?,,My F350 powerstoke whines under full throttle as u hear the turbo loud and clear
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
Yes, you should hear some whine, especially next to walls, buildings, other vehicles.
 

Bob_Fout

Oil Wanker
Joined
Sep 5, 2004
Location
Indiana
TDI
2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
Does this mean its not spooling up to full boost?,,IF not, what do I do to fix it?:mad:
Can't say for sure. How's the performance? Any smoke? Anyone near you who can look at requested vs. actual boost?

Sometimes these smaller turbos can't be heard by some people because of the higher frequency.
 

herbie lives

Well-known member
Joined
Jun 26, 2012
Location
el psao texas
TDI
2003 beetle TDI ALH
Can't say for sure. How's the performance? Any smoke? Anyone near you who can look at requested vs. actual boost?

Sometimes these smaller turbos can't be heard by some people because of the higher frequency.
well, maybe im tone deaf..lol..it doesnt smoke at all..how hard is it to hook up a boost gauge? Is there a plugged off port in the intake that I can use or do I need to drill and tap for one?
 

Lex4TDI4Life

Top Post Dawg
Joined
Jun 22, 2006
Location
NorCal
TDI
2001 Golf-Ute TDI GLS 5spd Manual
Personally, I never heard my perfectly functioning turbo until I ditched my muffler.
 

CoyoteStarfish

Veteran Member
Joined
May 25, 2011
Location
Miami, FL
TDI
01 Beetle
I did a cat/mufflerectomy on my Beetle. It's loud, but still quieter than say - a stock Cummins 12/24v(pre-commonrail) truck, a pickup with flowmaster mufflers, a "riced" out Honda, etc. It's a very nice tone and volume level if you like hearing your engine. In my experience, keeping the stock exhaust pipe diameter does not produce a harmonic drone at highway speeds either, but I can't speak for larger exhaust pipes.

Boost gauge - for mine I tapped out a port in the solid plastic intake pipe between the intercooler and intake manifold. It's easy enough to do since all you need is to release the hose clamps holding it in place to work on it outside the vehicle. Spray out any plastic shavings with a water hose and you're good to go.

As far as the turbo itself goes, you may have the dreaded sticky vanes that plague these VNT turbochargers. There are many detailed diagnostic techniques on this forum for checking vane operation - but - on the Beetle it is very hard to get in there and see the vane actuator move. What I do, is pull the vacuum line leading to the VNT actuator from the N75 valve and either apply direct vacuum from the pump (crude but effective) or use a vacuum tool (MityVac or equivalent) on the vacuum line. I also typically pull the charge pipe between the intercooler and intake and listen/feel the flow from the turbocharger as vacuum is applied. If you do not have a vacuum tool you can rent one from a retail auto parts store or pick one up on the cheap from Harbor Freight.

Here is the N75 valve (firewall, driver-side), and which line to remove:

[NOTE: The white capped valve is the N75 for VNT operation, next to it will be a black valve (N18) for EGR operation, disregard this one. Remove the vacuum line VERY CAREFULLY as the hose barbs tend to break easily.]

With the engine running and at an idle, apply vacuum. The engine should bog down a bit , and you should hear the turbocharger spool up. The bogging/spooling should be pretty linear to the amount of vacuum applied. If the spooling/bogging is delayed, does not return to normal when the vacuum is released or makes no changes-- then you have vane actuation issues. Vacuum should not drop off once applied, if it does - leaky vacuum line/connection or actuator.

Keep in mind, a vacuum tool can achieve higher vacuum levels than the engine vacuum pump - so if you do have sticky vanes this may free them up but "pop" them into a locked position so make sure you repeat the vacuum/release procedure until the actuation seems fluid and linear, in essence exercising / sweeping the vanes and releasing carbon buildup.

If the turbocharger vanes happen to pop closed (spooling) and stay that way once vacuum is released, you're in for some fun. Time to clean your turbocharger vanes. There are many schools of thought on this as far as what works, and what doesn't -- but typically removal of the turbocharger is required.
 
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snakeye

Veteran Member
Joined
Dec 13, 2009
Location
Montreal, Canada
TDI
2003 Jetta and Wagon, GLS 5sp
I normally just hear my turbo while it spools when I shift low.

Good advice CoyoteStarfish. For the vanes/actuator you can also reach behind the engine and press down on the vnt lever and see if it springs back easily all the way.
 

erbilabuc

Veteran Member
Joined
Jan 12, 2011
Location
Jacksonville, nc
TDI
2003 Green Jetta wagon
as a fellow powerstroke owner (99-7.3) you are not going to get the same sound out of a tdi that you are going to get of the powerstroke. Powerstroke turbo is about 4 times the size. The only place you will get a similar sound is the exhaust pipe if you take the tdi muffler off.
running on wvo
 
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