[Vwdiesel] Limp Mode Frustration

[James Hansen]

I've had the wastegate controller on a non-vnt fill with oil from blowby
over time, limiting how much it could actuate.  used a mighty-vac, and
sucked the oil out.  Could check for something like that in addition to what
was mentioned. Sounds like vanes, or actuation of vanes being the problem
tho.
It is common for granny driven vnt's to clog up for sure (internally
limiting vane travel).  The local diesel guys do quite  a few of them for
that- cleaning is certainly cheaper than replacing, but far from the
"textbook" answer.
-james

-----Original Message-----
From: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
Behalf Of Dave Cook
Sent: March-03-12 9:43 PM
To: VW Diesel Group
Subject: [Vwdiesel] Limp Mode Frustration

This is a friend's '01 Jetta TDI.  Keeps going into limp mode, sometimes
with a check engine light, sometimes without.  Has been this way for a long
time.

Last spring, I replaced all the vacuum lines while replacing the head
gasket, timing belt, and a few other bits in hopes of fixing this.  Also
replaced the N75 at that time.

Still goes in limp, and does it more often than not at this point.

I decided to try some more troubleshooting today.  In doing some driving, I
found that the ECU would show two different codes after going  "limp".

They were:

16618 - Boost Pressure Regulation
            P0234 -
35-00 - Limit Exceeded (Overboost Condition)
16492 - Manifold / Barometric Pressure Sensor (G71) / (F96)
            P0108 -
35-00 - Signal too High

They were showing up sort of alternatively, maybe a couple times one of them
and a couple times the other.  Or a couple one, then the other, then back to
the one.

Once, both popped up at the same time.

I was romping on it going up hills during this testing.  It only took a
couple seconds of heavy acceleration to cause limp to come up after having
shut down the car and clearing the codes.  

I then pulled the MAP sensor from the intercooler.  I noted a oily coating
on it, so I cleaned it off with air flow sensor cleaner.  No change on
reinstallation.

I'm thinking the problem might be the MAP sensor, but my friend doesn't want
to throw money at the car hoping something fixes it.  

Any other thoughts?
 
Dave Cook
_______________________________________________
Vwdiesel mailing list
Vwdiesel at vwfans.com
http://www.audifans.com/mailman/listinfo/vwdiesel