Replacing throttle body - 2005 Passat TDI

gorsuchmill

Member
Joined
Jan 15, 2010
Location
Baltimore, Maryland
TDI
2005 Passat Wagon
I'm fairly decent with a wrench, but by no means a skilled mechanic. Anyway, I've been told my throttle body is bad and needs to be replaced. How difficult is this as a job and what steps are involved?

Thanks in advance.
 

gorsuchmill

Member
Joined
Jan 15, 2010
Location
Baltimore, Maryland
TDI
2005 Passat Wagon
Not a gasser and the shop which diagnosed it seems to know what they're doing. Between the throttle body repair and others money will be real tight, so I'm trying to save where I can. Anyway, the shop told me there appears to be an internal electrical malfunction with the throttle body, which is causing it to lose communication with the whatever it is that it communicates with (I can't remember - ECM?)
 

Alchemy

Veteran Member
Joined
Jan 22, 2000
Location
N/A
TDI
None thanks to dieselgate
There is no throttle body on a Passat TDI, engine speed is regulated by fuel amount. These engines suck as much air (well, air and exhaust gas) as possible at all times, so there is no traditional throttle plate.

What issue are you having? Did they read a DTC (Diagnostic Trouble Code) and if so, what code was it? If you post that information here, people might be able to help guide you a little more.


Not a gasser and the shop which diagnosed it seems to know what they're doing. Between the throttle body repair and others money will be real tight, so I'm trying to save where I can. Anyway, the shop told me there appears to be an internal electrical malfunction with the throttle body, which is causing it to lose communication with the whatever it is that it communicates with (I can't remember - ECM?)
 

Questor

Active member
Joined
Jun 26, 2011
Location
Near Seattle WA
TDI
'05 B5.5 Passat Wagon -180k
The reason we're all chuckling on this side is that there is no throttle body on a diesel car...

There is a kind of flap valve they might be referring to (Search 'EGR' or 'EGR Cleaning', but ANY competent mechanic should know the difference... RUN!

What are the symptoms you're trying to have repaired?


Edit: Alchemy beat me to the punch, but yeah, DO let us know what is wrong with the car and perhaps we can steer you the right direction.
 
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gorsuchmill

Member
Joined
Jan 15, 2010
Location
Baltimore, Maryland
TDI
2005 Passat Wagon
I'm using the term throttle body because that is how it was communicated to me, not to mention that I have seen others on here comment that the newer diesels do have a version of throttle body. I understand it to be the same as the flap to which you are referring. Anyway, I don't recall the error code being thrown, but the car will suddenly go into limp mode with no warning. I can turn the car off and limp mode is gone, but returning more frequently to the point I can't drive the car.

Thanks for youe help.
 

aja8888

Top Post Dawg
Joined
Dec 25, 2007
Location
Texas..RETIRED 12/31/17
TDI
Out of TDI's
Pretty much the vast majority of limp mode cases with 2004-05 Passats discussed here have been the result of a split turbo/intercooler hose or a bad vacuum hose. I have experienced both types of failures.
 

gorsuchmill

Member
Joined
Jan 15, 2010
Location
Baltimore, Maryland
TDI
2005 Passat Wagon
Thanks and I sent a PM to him yesterday, but I'm looking to replace the body myself to reduce the cost. The part number is 03G128063J, which is identified as a "flap" by 1stVW Parts.
 

1854sailor

Resident Curmudgeon
Joined
Aug 10, 2004
Location
Westerly, RI
TDI
2015 Golf SE SportWagen, 2015 Golf SE Hatch Back.
Take the air inlet pipe off of the EGR and look inside, then do what Questor recommended: search "EGR cleaning". Just clean it and save yourself $350.00!
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
The throttle bodies fail on these sometimes. The set a DTC, the gears strip out. Not sure what your mode of failure is, but it could indeed be bad. Not hard to replace, just three Allen screws and the electrical plug.

As for semantics: Volkswagen calls this an 'intake manifold control flap', Mercedes-Benz calls it an 'EGR throttle valve', BMW calls it a 'throttle body' (or 'throttle valves', where equipped), Bosch calls it a 'throttle control valve'. So whatever you choose to call it, the term 'throttle body' fits, as if you saw it laying on the bench next to one from a gas VAG product, the only way you could tell the difference is that the diesel one spring loads open and the gas one spring loads shut.

But for the record, ALL newer diesels do indeed have throttles, some have several, and many older diesels do as well. People should study diesel engines throughout history up to and including present day before they spout off nonsense about "diesels don't have throttles" because that simply is not true.

As far as the throttle's purpose, well that is a lessen for another day.... ;)
 
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