Limp mode, low boost and turbo type

[RStevenson]

Hey guys, I just registered to post this. I have a 2006 VW Golf 1.9 TDI GLS I've been having problems with it going in and out of limp mode for a while. It all started with bad MAF sensor which has been replaced. I purchased a OBD scanner and cleared the MAF code and got a "p0299" code which I traced down to meaning underboost. The car has progressively gotten worse and now stays in limp mode even when the key is cycled and obviously has no power. My father and I tried our best to check the vacuum lines by sight/hearing and didn't find any leaks.
I would like to purchase a new N75 and a new actuator for the turbo as I'm thinking one of them is the culprit. The problem I'm having is I can't seem to find a reliable source on what type of turbo charger my engine has (the garret or borg warner) because from what I've read the garret actuators can be replaced and the BW cannot. I would really like to avoid having to replace the entire turbocharger. Any advice is appreciated, thanks.

 

[Searcher2]

Do you have any numbers from the plate? I had the same problem and found the lower hose for the intercooler had separated.

 

[RStevenson]

Do you have any numbers from the plate? I had the same problem and found the lower hose for the intercooler had separated.

Do you mean the plate on the turbo? I'll try and get that when I check all the lines and replace the n75 this week at some point. I'll be sure to check that intercooler hose too. Thanks.

 

[bbbbbq]

Your Golf with BEW engine code uses the BW KP39 turbocharger as stock equipment. Any reference to the Garrett VNT17 is an aftermarket upgrade.

The BW turbo does not have an actuator available separately. I recall some threads here that people try to retrofit a VNT17 actuator (which IS available seperately), with mixed results. I'm not sure if the issue is resolved, but it has to do with the actuator position output being inverse of the BW. Any experts, please chime in?

 

[RStevenson]

Reviving this thread because I STILL have not solved this issue. The car goes into limp mode in 3rd gear at 2500 RPM's and in 5th gear at 2000 just about every time. Is it safe to say that this is when the turbo requires more power and it can't actuate? In the winter months it's pretty much in limp mode only. I've replaced the N75 twice and checked the vacuum lines a few times.

Should I just go ahead and order the Garret VNT turbo from IDParts? Is it worth spending the money to take it to a shop to pinpoint exactly what the issue is? Money is very tight and I'm not sure what my next step should be....any help would be appreciated.

 

[wonneber]

Before you start throwing $$$ at the car on 'maybe this is it':::
I know its not the time to work outside but you may have to pull the turbo out to diagnose it.
There's plenty of write-ups how to diagnose limp mode with the turbo.
Also search cleaning the turbo for when you have the old one out.
I changed my actuator because I found it was not smooth.
The new one was easy to move with vacuum.
I also tested I was getting vacuum to the actuator while I was driving.

Rich W.

 

[wonneber]

Forgot
Also search U-Tube for videos.

 

[RStevenson]

Thank you, I spent a couple hours searching the forums and came across this thread:

http://forums.tdiclub.com/showthread.php?t=179589

on how to diagnose underboost issues and this one, explaining how to chemically clean sticky turbo vanes:

http://forums.tdiclub.com/showthread.php?t=246287&page=4

hopefully with this knowledge I can solve the issue, also its -14 degrees here in Canada atm so I'm praying for warmer weather.

 

[BobnOH]

Did you read this stuff over at the Ross Tech wiki?
16683/P0299/000665
If you still have the original cloth covered vacuum tubes, you might just want to replace them. Check the wiring stuff that goes down to the turbo. Check if you can hand operate the actuator/vanes, and apply vacuum to the unit to see if it actuates.

 

[Rembrant]

Should I just go ahead and order the Garret VNT turbo from IDParts? Is it worth spending the money to take it to a shop to pinpoint exactly what the issue is? Money is very tight and I'm not sure what my next step should be....any help would be appreciated.

If money is tight, buying a $1200+ dollar turbo is an awful expensive item to buy without being 100% sure it is bad. I'd pay a shop to diagnose it if I didn't have the tools/ability to check it myself.

Where in Canada are you? If you have to take it to a shop, make sure it is a VW shop. A regular old garage may be little help.

 

[RStevenson]

I'm in Windsor Ontario, there's a place here called Heinz garage that specializes in VW, and there may be a couple others. I might just replace all the vacuum lines and clean out the turbo when I have a few days off.

 

[Stan TDI]

I have had this happen a number of times with different TDI's. For me (luckily) it has always been resolved replacing the vacuum lines. I used high temp silicone lines. I am not sure what the 2006 needs. I used Mcmaster dot com - here is an example of one of the lines:
Metric High-Temperature Silicone Rubber Tubing Soft, 3 mm ID, 8 mm OD, Opaque Black, 10 ft. Length

 

[RStevenson]

I'm in the process of ordering new OEM vacuum lines and a vacuum pressure tester from fixmyvw.com. I'm planning on replacing the lines and cleaning out my turbo with the Easy Off chemical cleaning method. I'm just waiting for the holidays to be over and for the weather to warm up a bit. I will update this post with my results. Fingers crossed.

 

[RStevenson]

RESOLVED

For anyone that stumbles on this thread while searching for a similar issue... my problem was a loose EGR cooler which caused the lower pipe to the turbo inlet to split in multiple places on the flex part of the pipe. The EGR pipes are prone to breaking if the cooler isn't secured properly. I was worried the entire time I would have to shell out for a new turbo, turns out mine works fine.

Here's a link the the replacement pipe:
http://www.kermatdi.com/egr-cooler-lower-pipe-mk4-bew-stock/

This pipe only works with the stock turbo.

 

[LarryT]

I'm having this same issue with the P0299 Under Boost on 2005 Passat TDI.

Car is in Limp mode with no codes and blowing black smoke. when Idling car has a ton of power but when in drive it wont even pull it self.

these are the things that I have checked so far.

1) Actuators to VNT. It moves at start about 4 - 16Lbs. of mercury.

2) Actuator is ok and holds it's pressure.

3) Ck turbo boost control valve N-75 with vag com. It has 10 - 19Lbs pressure - brake vacuum pump has vacuum leaking at hose connectionloose in vacuun oump.

4) Ck fuel injectors quantity #1). injector 0.21 #2). 0.00 #3). 0.00 #4). 0.31.

5) Ck for pluged exhaust with vacuum gage. Ehaust checks to be free.

6) Ck intake EGR. No corrosion build up. ck with vag com has 100% duty cycle.

VNT (verible nozzle turbo), actuators, oxygen sensors, & intercooler.

7) used a smoke machine on Intercooler. No leaks at Intercooler and no leaks
on hoses.

Please any help will be greatly appreciated. Thanks in advance!

 

[BobnOH]

From Ross Tech wiki-
Check vacuum supply from the vacuum reservoir located in the valve cover for leaks