2005 1.9tdi PD BEW Bora Wagon Boost drop and shudder.

[Winning]

Vehicle Is a 2005 BEW 1.9 pd tdi.
The issue is the engine will shudder three times as the boost drops three times. This only happens once the engine is warmed up. When the fuel tank is full it happens less often. Seems to happen at the same points in my regular drive route, usually while driving up hill. but also, occasionally driving on flat ground. I installed a boost gauge and can see the boost needle drop three times as the three shudders happen. After the shudder happens, when i stop at a stop light the idling may be lumpy. But then the next time I stop it will be smooth or lumpy. Sometimes i can feel the idling being lumpy as im breaking but when the car fully stops the idling rpm jumps for a split second and is then really smooth again. Please help me with this shudder/ boost drop it is driving me insane.

tests i have done.
lift pump flow rate tested good on the low side but good.
Swapped anti shudder valve no noticeable effect.
Swapped camshaft position sensor no noticeable effect
Swapped injector harness slightly improved idle.
Swapped Tandem Pump no noticeable change.
checked wiring at turbo vane position sensor. It had ware spots that were repaired.
Swapped electronic egr valve no noticeable effect.
Tried running liquimoly injection cleaner. No noticeable change.


things that are not stock
colt stage 2 cam
injectors with 1043 tips
injection quantities look good till the car is warmed up then 1 and 2 get out of Wack
1 reads =2.99 and 2 reads -3.01. I'm not sure if these numbers are correct or a symptom of the issue. as the engine will be idling and running fine with these numbers. no smoke or hazing.

All emissions components are in place and seem to be operating properly.
swirl flaps in the intake can be a bit sticky. but seem to operate fine under vacuum on the actuator.
The vacuum actuator on the egr cooler valve seems to operate fine but where it mounts to the bracket has a little play.
Intake manifold has been cleaned of the black sludge build up.


vcds scan

Wednesday,03,April,2024,17:57:43:55675
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 11 x64
VCDS Version: 23.11.0.0 (x64) HEX-V2 CB: 0.4643.4
Data version: 20231027 DS351.0
www.Ross-Tech.com


VIN: WVWSR61J85W048066 License Plate:


Chassis Type: 1J (1J - VW Golf/Bora IV (1998 > 2006))
Scan: 01 02 03 08 15 16 17 19 22 29 35 36 37 39 46 47 55 56 57 75
76

VIN: WVWSR61J85W048066 Mileage: 347360km-215839miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 038-906-016-BEW.lbl
Part No SW: 038 997 016 R HW: 028 101 181 2
Component: R4 1,9L EDC G000SG 0282
Revision: 12345678 Serial number: VWZ7Z0D0837192
Coding: 0150031
Shop #: WSC 66672 142 86670
VCID: 2D0718A9E10CA9D2B45-5184
VINID: 9E69E388605A2059C0108006185B41F7EC

No fault code found.
Readiness: 0 0 0 0 0

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 1C0-907-37x-ABS.lbl
Part No: 1C0 907 379 L
Component: ABS FRONT MK60 0101
Coding: 0001025
Shop #: WSC 01266 785 00200
VCID: 33330ED10728FF22E21-5184

No fault code found.

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 6Q0-909-605-VW5.lbl
Part No: 1C0 909 605 F
Component: 17 AIRBAG VW61 0108 0003
Coding: 12599
Shop #: WSC 01266
VCID: 270BEA81C6F083824E9-5160

1 Fault Found:
00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 1J0-920-xx5-17.lbl
Part No: 1J5 920 906 Q
Component: KOMBI+WEGFAHRSP VDO V03
Coding: 15232
Shop #: WSC 00000
VCID: 3B2326F12A7837623A1-5160
WVWSR61J85W048066 VWZ7Z0D0837192

3 Faults Found:
01176 - Key
07-10 - Signal too Low - Intermittent
01336 - Company Data Bus for Comfort System
49-10 - No Communications - Intermittent
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
Address 19: CAN Gateway Labels: 6N0-909-901-19.clb
Part No: 6N0 909 901
Component: Gateway K<->CAN 0001
Coding: 00006
Shop #: WSC 01266
VCID: 70B9C1DD33BE843ADF3-5160

2 Faults Found:
01336 - Company Data Bus for Comfort System
49-10 - No Communications - Intermittent
01304 - Radio
49-00 - No Communications

-------------------------------------------------------------------------------
Address 46: Central Conv. Labels: 1C0-959-799.lbl
Part No: 1C0 959 799 C
Component: 8A Komfortgerát HLO 0004
Coding: 00258
Shop #: WSC 01266
VCID: 372B3AC116501302DE9-4B1E

Subsystem 1 - Part No: 1C1959801A
Component: 8A Tõrsteuer.FS KLO 0202

Subsystem 2 - Part No: 1C1959802A
Component: 8A Tõrsteuer.BF KLO 0202

Subsystem 3 - Part No: 1C0959811A
Component: 8A Tõrsteuer.HL KLO 0202

Subsystem 4 - Part No: 1C0959812A
Component: 8A Tõrsteuer.HR KLO 0202

4 Faults Found:
01333 - Door Control Module; Rear Left (J388)
49-10 - No Communications - Intermittent
00929 - Locking Module for Central Locking; Front Passenger Side (F221)
27-10 - Implausible Signal - Intermittent
00930 - Locking Module for Central Locking; Rear Left (F222)
27-10 - Implausible Signal - Intermittent
00931 - Locking Module for Central Locking; Rear Right (F223)
27-10 - Implausible Signal - Intermittent

End----------(Elapsed Time: 05:09, VBatt start/end: 12.5V/12.4V)-----------


If you have made it this far, I really appreciate you reading all this!

 

[wonneber]

My usual suggestion is clean all the ground wires under the hood.
If any of those are bad including the body grounds then anything that grounds to the body is bad.
Hope this helps.

 

[Winning]

My usual suggestion is clean all the ground wires under the hood.
If any of those are bad including the body grounds then anything that grounds to the body is bad.
Hope this helps.

Thanks i will go through all the grounds again and check to see if i missed any.

 

[Winning]

Thanks i will go through all the grounds again and check to see if i missed any.

Went through them again this is the third time. Only grounds i have not gone through are the rear break light grounds. I even added a ground from the alternator to the battery. Nothing has changed, symptoms are the same.

 

[Winning]

Could this shudder and drop in boost be cause by a failing turbo or faulty variable geometry vanes? I could see it being the variab vanes slaping shut and open repetedly. How would i look at the vane position info and record it with boost info in rosstec vcds?

 

[DuraBioPwr]

Might be the vacuum lines or the N75 valve that controls the turbo actuator. Since you got VCDS graph N75 output while it does it. Determine if it coincides with the shuddering. If the output or desired to actual is correct then investigate the vacuum lines.

 

[Winning]

Might be the vacuum lines or the N75 valve that controls the turbo actuator. Since you got VCDS graph N75 output while it does it. Determine if it coincides with the shuddering. If the output or desired to actual is correct then investigate the vacuum lines.

Thanks for the response!
Vaccume lines are maybe 3 year old silicone lines. I had another n75 i swapped in, and it still did it. Not sure how well either n75 is working. They bothe seem to do what they are suposed to when i give throttle and let it off. When I run the n75 test in vcds it says complete. Im not sure how to run that test with vcds or what the test shoud do. There is a chattering sound that goes with the boost drop. The chattering sound is making me think it may have something to do with the variable veins on the turbo. The veins are controlled by Vaccume so I will go through all the vaccume lines agian.

 

[Winning]

Up date i swaped in new vaccume lines and another maf i had sitting around. Took it for a drive seemed to improve idling. Then she threw a code. And went into limp mode. Code thrown was 16683 boost pressure regulation p0299 control range not reached. It would make sence that the boost drop and chatter is coming from the turbo failing. So i opend up the hose on the inlet side of the compressor wheel. And used my finger tip to check for play. Turbo has no play that i can feel. But there is more resistance to spining it than i think there should be. Thoughts?

 

[Winning]

Turned out this code was caused by a kink in one of the new vaccume lines. Rerouted that line and cleared the code. Did some.more driving and the code had not come back. But the shudder and rough idle seem to be the same as before.

 

[Zak99b5]

There should be a little play in the turbo; the shaft sits in a journal bearing that has room for oil to flow into it around the shaft. With the engine off, oil is not filling the bearing and taking up that space. Mind you, it shouldn't move more than a touch, but you should feel it wiggle a little.

 

[DuraBioPwr]

Rough idle and shudder could be air in the fuel system. Put a clear return hose on and look for bubbles.

 

[Winning]

Rough idle and shudder could be air in the fuel system. Put a clear return hose on and look for bubbles.

I will give this a shot. When I did my fuel filter last, I ran a can of liquiMoly from a clear vessel. There were no bubbles. But i guess there could be an air leak between the tank and fuel filter. Any recommendations on what clear fuel line i should use?

 

[shoebear]

I would also also check the:

1. Brake booster vacuum hose for leaks
2. Rest of the vacuum system for leaks
3. Turbo vane actuator for stickiness

The brake booster hose runs from the vacuum output of the tandem pump to the brake booster. There are two sections, and leaks commonly develop in the hard plastic rear section. There is a tee between the sections that supplies the rest of the vacuum system.

1. Disconnect the small hose from the tee. Disconnect the booster hose from the booster (you'll probably need a tool to pry it out). Then plug the booster end and apply vacuum to the tee with a mityvac or similar pump. If you can't create/hold vacuum, you have a leak. Or just disconnect the entire hose and inspect. Cracks are usually on the back side of the hard plastic section where you can't see them without a mirror or without removing the hose. Leaks here can be fixed temporarily with electrical tape while you order a new one.
2. Put your mityvac on the small hose and pull a vacuum. You should see, at most, a very slow decay in vacuum. If this isn't the case, track down the leak.
3. Disconnect the vacuum line from the turbo, connect the mityvac, and alternately apply and release vacuum while holding the turbo vane actuator with your hand. You should feel the actuator move smoothly with vacuum and come to rest on the stop at full vacuum. If you have trouble seeing if the actuator hits the stop or not, you can hold a small scrap of paper at the stop to see if the paper becomes pinned in place at full vacuum. If the actuator sticks or can't go all the way to the stop, clean the turbine (exhaust) side of the turbocharger. The easiest way to do this is with oven cleaner; the most thorough way is to remove your turbo, disassemble it, and clean it.

On my daughter's 2005 BEW New Beetle, the vacuum hose to the turbo had a connector about at the halfway point. I found that the vacuum hose around the connector was rotten and crumbling, so I replaced that section.

Hope this helps.

 

[Winning]

There should be a little play in the turbo; the shaft sits in a journal bearing that has room for oil to flow into it around the shaft. With the engine off, oil is not filling the bearing and taking up that space. Mind you, it shouldn't move more than a touch, but you should feel it wiggle a little.

I will give this another look when i am under the car testing the vaccume actuator on the turbo.

 

[Winning]

I would also also check the:

1. Brake booster vacuum hose for leaks
2. Rest of the vacuum system for leaks
3. Turbo vane actuator for stickiness

The brake booster hose runs from the vacuum output of the tandem pump to the brake booster. There are two sections, and leaks commonly develop in the hard plastic rear section. There is a tee between the sections that supplies the rest of the vacuum system.

1. Disconnect the small hose from the tee. Disconnect the booster hose from the booster (you'll probably need a tool to pry it out). Then plug the booster end and apply vacuum to the tee with a mityvac or similar pump. If you can't create/hold vacuum, you have a leak. Or just disconnect the entire hose and inspect. Cracks are usually on the back side of the hard plastic section where you can't see them without a mirror or without removing the hose. Leaks here can be fixed temporarily with electrical tape while you order a new one.
2. Put your mityvac on the small hose and pull a vacuum. You should see, at most, a very slow decay in vacuum. If this isn't the case, track down the leak.
3. Disconnect the vacuum line from the turbo, connect the mityvac, and alternately apply and release vacuum while holding the turbo vane actuator with your hand. You should feel the actuator move smoothly with vacuum and come to rest on the stop at full vacuum. If you have trouble seeing if the actuator hits the stop or not, you can hold a small scrap of paper at the stop to see if the paper becomes pinned in place at full vacuum. If the actuator sticks or can't go all the way to the stop, clean the turbine (exhaust) side of the turbocharger. The easiest way to do this is with oven cleaner; the most thorough way is to remove your turbo, disassemble it, and clean it.

On my daughter's 2005 BEW New Beetle, the vacuum hose to the turbo had a connector about at the halfway point. I found that the vacuum hose around the connector was rotten and crumbling, so I replaced that section.

Hope this helps.

Thanks for this check list. I will go through with my mighty vac and chack all of these. I did recently replace the line from the vacuume pump to the booster with the check valve. I guess it could have failed. I will check it again. I did replace all the vaccume lines yesterday except the run down to the turbo actuator and the run to the intake swirl flaps. I ran out of time. I will replace these when checking everything with the vacuume pump.

 

[Winning]

So up date still have the shudder. I swaped in a new garret vnt17 turbo, All new vaccume lines. Found two broken vaccume actuators the swirl flap and the egr cooler flap actuators. Reeplaced them. These changes greatly improved the idling and exceleration. But the shudder is still there. I suspected maybe an ecm or electric issue. So i swapped the ecm with another on I had. This also improved the idle a bit more and the general engine responce. But the shudder and boost drop is still there. Im starting to suspect the wiring harness on the passange side of the engine. Also there are no engine codes. Any thoughts?

 

[DuraBioPwr]

Did you ever chk for air in the return lines when its doing the lumpy idle thing? Combustion gases might be getting into the fuel galleries and starving of fuel here and there. Return line test will show this.

 

[shoebear]

Looking at your codes from Apr 6 -- It looks like you have a Comfort CANbus issue. This likely doesn't have anything to do with the shudder, but I thought I'd point it out. There are several YouTube channels that feature troubleshooting a CANbus fault fairly often - a couple are:

• Pine Hollow Auto Diagnostics
• South Main Auto LLC

The basic procedure seems to be:

• Get a schematic and understand the bus. Look for common-sense ways to prioritize the steps below.
• Find a connector that splits the bus. Unplug and test on both sides for 120 ohms between CAN low and CAN high. This tests for the presence of the termination resistors on both ends of the bus.
• Check all the connectors on the bus for electrical faults like corrosion, frayed insulation, etc.
• Remove bus components one at a time to isolate the fault.
• The fault can be a bad component, but more often, it is some kind of wiring fault.

 

[shoebear]

Back to the shudder -- this is kind of a chicken and egg thing. Does boost drop, causing the engine shudder? Or does the engine shudder cause the boost drop? You might try logging Engine Measuring Block 011 in VCDS -- it will show engine RPM, requested boost, actual boost, and N75 signal, and it should help determine the root source of the shudder.

VCDS includes VC Scope that allows you to reply your log files; however, I've found it clumsy and difficult to use. I use a very old log plotter from forum user and vendor @JollyGreenGiant that works well, but not perfectly because of minor format changes in the VCDS logs over the years that have not been updated in the JGG software. There are other free log viewers out there also that I haven't tried -- search Google for vcds log viewer.

 

[Winning]

Did you ever chk for air in the return lines when its doing the lumpy idle thing? Combustion gases might be getting into the fuel galleries and starving of fuel here and there. Return line test will show this.

I added clear lines to the fuel delivery and return lines off the engine. I see no bubbles no mater the rpm range. But the issue only seems to happen under load in fourth or fifth gear.

 

[Winning]

Back to the shudder -- this is kind of a chicken and egg thing. Does boost drop, causing the engine shudder? Or does the engine shudder cause the boost drop? You might try logging Engine Measuring Block 011 in VCDS -- it will show engine RPM, requested boost, actual boost, and N75 signal, and it should help determine the root source of the shudder.

VCDS includes VC Scope that allows you to reply your log files; however, I've found it clumsy and difficult to use. I use a very old log plotter from forum user and vendor @JollyGreenGiant that works well, but not perfectly because of minor format changes in the VCDS logs over the years that have not been updated in the JGG software. There are other free log viewers out there also that I haven't tried -- search Google for vcds log viewer.

I have ross tec vcds i will graph block eleven and take a screen shot when it happens.

 

[Winning]

I went through the common wiring harness issue areas today. Found acouple areas where wires were damaged from the plastic loom rubbing on them. I fixed these. Also found the reverse switch off the trans had a break in it. I fixed this. Then while under the car i found one of the three nuts holding the exhaust pipe to the turbo had loosened about a turn leaking ehaust gas. I tightened this back down and checked the others and they were all snug.

 

[Winning]

Looking at your codes from Apr 6 -- It looks like you have a Comfort CANbus issue. This likely doesn't have anything to do with the shudder, but I thought I'd point it out. There are several YouTube channels that feature troubleshooting a CANbus fault fairly often - a couple are:

• Pine Hollow Auto Diagnostics
• South Main Auto LLC

The basic procedure seems to be:

• Get a schematic and understand the bus. Look for common-sense ways to prioritize the steps below.
• Find a connector that splits the bus. Unplug and test on both sides for 120 ohms between CAN low and CAN high. This tests for the presence of the termination resistors on both ends of the bus.
• Check all the connectors on the bus for electrical faults like corrosion, frayed insulation, etc.
• Remove bus components one at a time to isolate the fault.
• The fault can be a bad component, but more often, it is some kind of wiring fault.

How could the can bus fault cause the issue i am having?

 

[shoebear]

How could the can bus fault cause the issue i am having?

The CANbus issues probably don't relate to your engine issues. I just noticed them and made my post in case you want to track down those issues.

 

[Winning]

The CANbus issues probably don't relate to your engine issues. I just noticed them and made my post in case you want to track down those issues.

Thanks. I will track them down they are next on mynlist now.

 

[Winning]

I made a bloc 11 graph
Red: engine speed
Green: requested boost
Yellow: actual boost
Grey: Charge pressure control duty cycle
The shudder happend 3 times in the graph where actual boost yello line drops while requested boosy green line stays steady.

 

[Winning]

I made a bloc 11 graph
Red: engine speed
Green: requested boost
Yellow: actual boost
Grey: Charge pressure control duty cycle
The shudder happend 3 times in the graph where actual boost yello line drops while requested boosy green line stays steady.

I see that the actual boost is going back and forth above and below the requested boost. In other graphs i can find of this the actual boost is not doing this in properly functioning cars.
Is this a sign of a n75 dynamically failing or is this more likly a collapsing vaccume line? I just replaced the vaccume lines with duralsat lines. It was doing the shudder before and after replacing the vaccume lines.

 

[Winning]

Ok i put in another n75 with the stock fourmed vaccume lines. I swaped it in with the other two vaccume actuators for the egr and intake swirl flaps as a unit. How the two bolts undo the whole vaccume valve assemby with the fitted hoses thats what i swapped in. Only vaccume components i left were the lines runing down to the turbo and the line running to the intake swirl flaps. I tested them and they hold vaccume. Also disasembeled both n75 valves. I used a file to cut through the metal bezel holding the peaces together on the side oposite the nipples. Both n75 valves had gunk in the one oily the other some white substance. I cleaned all parts with nonclorinated brake cleaner, then wiped all the parts down with a microfiber towel. Reassemblel using the metal bezel and tightened it down with a ziptie. Now I know nothing in them is sticking because of gunk. I also know the both have intact rubber diaframs.

 

[Kramer]

If this was happening all the time, I would say test the MAP sensor, but this is only when it is hot? I doubt the coolant sensor would do this alone, but you may want to slap a multimeter on those sensors to make sure they are running proper. It's like the ECU isn't getting a consistent signal from one of them.

 

[shoebear]

I made a bloc 11 graph
Red: engine speed
Green: requested boost
Yellow: actual boost
Grey: Charge pressure control duty cycle
The shudder happend 3 times in the graph where actual boost yello line drops while requested boosy green line stays steady.

I don't use the VC scope app -- I take a log and then look later with a log reader. But the oscillations in actual boost (even when the shudder doesn't occur) don't look normal to me. Someone who does use the VC scope should chime in here.

In thread post #8, you said of the turbo, " But there is more resistance to spining it than i think there should be." Since then, you changed the turbo altogether and the problems improved, but didn't go away. I wonder if your turbo is getting sufficient lubrication. If not, the shaft might be seizing and causing both the little oscillations and the big oscillations (the shudder). This would persist from one turbo to the other, since the fault would be in the lube system, not the turbo.

Try this:

• Unplug the injector harness connector from the driver's side of the head -- so the engine won't start.
• Disconnect the turbo drain line from the block just above the oil pan.
• Hold a jar or can under the drain line while someone cranks the car. Within a second or so, you should get a nice steady stream of oil into your catch container. If you don't, something isn't working. Probably your oil feed or drain line, but could be a bad oil pump.