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

[Winning]

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.

Yes it is only doing it when warmed up. I will graph the maf and map using ross tec vcds to see if they are doing any strange when it happens.

 

[Winning]

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.

Do you know what the oil pressure should be? I can rig up a oil pressure gauge to check this. Also it has a new garette turbo now. So it spins eaisly and the actuator is new.

 

[Winning]

here is a block 11 graph after replacing the n75 with a spare i cleaned out and all for the other vaccume controlers as well as the stock fitted vaccume lines. The blip in boost is still happening. But the strange osilation seems to have gone away.

Ok so i was sitting in the car and turned off the ac and the injecton quantities got worse. Then i switched back on the ac and the got better again. Now im suspecting something to do with the can bus system error and maybe that is causing some feeback or electtical issue effecting fueling?

 

[Winning]

Ok, i did my morning drive and graphed the shudder with more sensors. Here are the blocks i graphed, and the graphs.

It looks like the maf is doing the odd ocilation too. Im really starting to suspect some wiring issue or feed back issue. I did unplug what i blieve is the comfort can bus. The box with two plugs to the left of the steering column under the dash. This seemed to have no effect on the shudder and my power windows and key fob unlock/ lock buttons stopped working while this unit was unpluged. I could really use some help. I was suspecting the in tank lift pump of intermitant failing or not providing enough fuel. But i can hear the lift pump running at idle and for a second when i first turn the key. But these odd osilations in the sensor reading point to electrical short or failing electrical component?
Also yesterday i parked and when i went to start the car i got a crank no start situation. That is untill i disconnected the positive battery terminal for a few seconds and reconeccted it. Then i had to cranke the engine before it started to even begin to start firing. Unfortunatly i did not have my computer with me to check for codes before disconecting the battery. And when i got home and scand for engine codes there were none.

 

[shoebear]

Try unplugging your MAF. It will set a code, but the ECU will fall back to default values and the engine should run OK without it.

But earlier, I hypothesized that something is causing your ECU to pull boost via the N75, which causes the shudder. When the turbo drops, it would also cause the MAF to drop, because less air would be flowing. I don't know why the ECU would be yanking boost, though. I'm hoping for other input about things to check that would cause the ECU to do that. You wondered about the CPS -- I would think an intermittent signal from that would do it -- but there may be other things to check.

Any chance you have access to an oscilloscope and could tap into the CPS signal at the ECU? In addition to a bad CPS, you might have an intermittant wiring fault, and a scope back-probed into the CPS wire at the ECU should reveal that. If you don't have a scope, there are inexpensive ones for sale on Amazon. One of my favorite YouTubers, Pine Hollow Auto Diagnostics, uses a 4-channel PicoScope, which I would love to have, but it's more money than I can justify. But a 2-channel should be fine, like this one: https://www.amazon.com/Echouswin-Oscilloscope-Handheld-Bandwidth-Automotive/dp/B0CTXJ6Z6

 

[Winning]

Try unplugging your MAF. It will set a code, but the ECU will fall back to default values and the engine should run OK without it.

But earlier, I hypothesized that something is causing your ECU to pull boost via the N75, which causes the shudder. When the turbo drops, it would also cause the MAF to drop, because less air would be flowing. I don't know why the ECU would be yanking boost, though. I'm hoping for other input about things to check that would cause the ECU to do that. You wondered about the CPS -- I would think an intermittent signal from that would do it -- but there may be other things to check.

Any chance you have access to an oscilloscope and could tap into the CPS signal at the ECU? In addition to a bad CPS, you might have an intermittant wiring fault, and a scope back-probed into the CPS wire at the ECU should reveal that. If you don't have a scope, there are inexpensive ones for sale on Amazon. One of my favorite YouTubers, Pine Hollow Auto Diagnostics, uses a 4-channel PicoScope, which I would love to have, but it's more money than I can justify. But a 2-channel should be fine, like this one: https://www.amazon.com/Echouswin-Oscilloscope-Handheld-Bandwidth-Automotive/dp/B0CTXJ6Z6

Unfortunaly i do not have access to an ociliscope. Do you know what the procedure is for testing cam and crank sensors with resistance and volatages that testing the given wires? From what i have found the engine will stop running if the crank sensor fails. But if the cam is failing it can cause the symptoms i am seeing. I also found that both can and crank sensors tend to fail with heat. So testing them warmed up with a hair dryer may show that they are failing while at room temp they may test good. This would explain why it only happens when the car is warmed up.

 

[shoebear]

The only sure way I know to test a crank or cam sensor is with a scope. Looks like my link above doesn't work, but if you search Amazon for "echouswin handheld oscilliscope automotive" you will find the scope I linked for $52. It's 2-channel -- so you can monitor both the cam and crank sensors at the same time. Yes, it takes some time to learn how to use it, but there is no tool as useful when diagnosing difficult problems.

Yes, you can apply heat, and maybe you'll find the bad sensor that way. Or you can just replace them. Those are both decent ideas, but you've been chasing this so long and have applied so many different parts to it that you might want to know the answer for sure before installing new parts.

 

[Winning]

The only sure way I know to test a crank or cam sensor is with a scope. Looks like my link above doesn't work, but if you search Amazon for "echouswin handheld oscilliscope automotive" you will find the scope I linked for $52. It's 2-channel -- so you can monitor both the cam and crank sensors at the same time. Yes, it takes some time to learn how to use it, but there is no tool as useful when diagnosing difficult problems.

Yes, you can apply heat, and maybe you'll find the bad sensor that way. Or you can just replace them. Those are both decent ideas, but you've been chasing this so long and have applied so many different parts to it that you might want to know the answer for sure before installing new parts.

I found a febi brand cam shaft sensor for 6 dollars shipped after a coupon code. Thats a bit less than the osiliscope. I may be able to borrow an osiliscope to do testing if it is not the cam position sensor. First i will start with continuity test through the harness. After inspecting the whole engone harness for wearthroug and shorts. If there is a short in the harness I missed it is a break inside the insulation that can not be seen visually.

 

[Winning]

Up date. I added an aditional ground strap from the transmission housings ground point to rite next to the plug for injector wiring harness on the drivers side of the head. Studder is still there but it has lowered the block 13 injection quantity values some. I was in there inspecting the ground on the alternator that has the wiring to the ac compressor and the two wires to the alternator on it. I unwraped and did a continuity test on the ac and alternator wires and checked them for damage. There was one small wear mark nere the plug over the starter. But nothing through the installation

 

[shoebear]

Grounding problems can cause crazy symptoms.

 

[BobnOH]

How to test BEW Cam/Crank Sensors?

Hello all. I got an 04 PD that runs like the timing is extremely retarded. I've read through the threads, and it leads me to believe that I may have one of two problems. Either the sensors are faulty or the timing belt is off (BTW it is not throwing any codes whatsoever). I'm waiting on the...

forums.tdiclub.com

EDIT- That thread is not especially helpful.

 

[shoebear]

Thank you, Bob, for the reminder that practically anything we need to know about these cars is on this site. The key is finding it, which you did for us.

 

[BobnOH]

The user contributed google hack is a gem!

Programmable Search Engine

cse.google.com

 

[Winning]

How to test BEW Cam/Crank Sensors?

Hello all. I got an 04 PD that runs like the timing is extremely retarded. I've read through the threads, and it leads me to believe that I may have one of two problems. Either the sensors are faulty or the timing belt is off (BTW it is not throwing any codes whatsoever). I'm waiting on the...

forums.tdiclub.com

I followed you link and found the torsion value in the thread should be 4.9 or so. Mine is currently at 0 untill warm then it is 0.5. I was under the impression it should be 0 to pluss or minus .5. This is where mine was before replacing the warn cam lifters and timing belt. I went with a colt stage two cam because of how it is made and not just case hardened like the stock cam. Should this cam be set to a torsion value of 4.9? I have see a bunch of diffrent numbers recomended but none as high as 4.9 before.

 

[Winning]

I followed you link and found the torsion value in the thread should be 4.9 or so. Mine is currently at 0 untill warm then it is 0.5. I was under the impression it should be 0 to pluss or minus .5. This is where mine was before replacing the warn cam lifters and timing belt. I went with a colt stage two cam because of how it is made and not just case hardened like the stock cam. Should this cam be set to a torsion value of 4.9? I have see a bunch of diffrent numbers recomended but none as high as 4.9 before.

Set the timing to 4.9. Had more consistant power now from 1k all he way through to nearly 5k. But the shudder is still there seems slightly improved. Down shifting on a steep grade or excelerating all out up a steep hill will shift the torsion value to 5.4. So i will be droping it down to 4.5 so it wont exceed 5.

 

[burpod]

email me the .csv logs

i have my BEW at +0.5 and runs damn near perfect with that. but, lots of little factors in there with tune etc. boost oscilliations will be something different

 

[burpod]

unlike the ALH, where you set the torsion value (cam/crank) will have an affect on the fueling maps beause the injectors are cam-driven. if you're putting it to +5.0 that's crazy town and likely a bandaid for something. from what i've seen, most stock BEWs are +2.0 to +2.5, it should be handwritten on the tb cover. not sure why....

 

[Winning]

unlike the ALH, where you set the torsion value (cam/crank) will have an affect on the fueling maps beause the injectors are cam-driven. if you're putting it to +5.0 that's crazy town and likely a bandaid for something. from what i've seen, most stock BEWs are +2.0 to +2.5, it should be handwritten on the tb cover. not sure why....

There is a tag that has long sence lost its writing. Just a white sticker where the timing set value should be. Also the engine has been fitted with a colt stage 2 cam shaft. Which i cant find any info on where the timing should be set for it. Im going to have to look into how to get .cvs logs. I have not done that before.

 

[burpod]

There is a tag that has long sence lost its writing. Just a white sticker where the timing set value should be. Also the engine has been fitted with a colt stage 2 cam shaft. Which i cant find any info on where the timing should be set for it. Im going to have to look into how to get .cvs logs. I have not done that before.

if you're playing graphs in vc-scope then you have the logs, you just have to upload or email them

it can never be harmful to have cam/crank be spot on. thats what torsion value is. being 5deg out seems not right. i can understand maybe 1-2deg for whatever reason

 

[Winning]

unlike the ALH, where you set the torsion value (cam/crank) will have an affect on the fueling maps beause the injectors are cam-driven. if you're putting it to +5.0 that's crazy town and likely a bandaid for something. from what i've seen, most stock BEWs are +2.0 to +2.5, it should be handwritten on the tb cover. not sure why....

This is the link to the thread talking about setting timing at 4.9.

TDI Cam Timing Adjustment (for rough idle) How-to (with pics)

Well, after reading the rough idle thread, I finally did my cam timing adjustment. I took pictures of the mechanical part of the adjustment, my computer screen on my laptop doesn't show up very well on my camera, so maybe someone else can upload those pictures. Anyway, here is a little writeup...

forums.tdiclub.com

 

[burpod]

This is the link to the thread talking about setting timing at 4.9.

TDI Cam Timing Adjustment (for rough idle) How-to (with pics)

Well, after reading the rough idle thread, I finally did my cam timing adjustment. I took pictures of the mechanical part of the adjustment, my computer screen on my laptop doesn't show up very well on my camera, so maybe someone else can upload those pictures. Anyway, here is a little writeup...

forums.tdiclub.com

people in old threads saying what timing to use is kinda meaningless tho

 

[Winning]

if you're playing graphs in vc-scope then you have the logs, you just have to upload or email them

it can never be harmful to have cam/crank be spot on. thats what torsion value is. being 5deg out seems not right. i can understand maybe 1-2deg for whatever reason

What graphs would you like me to post? I posted some earlier in this thread. I can make any other ones too. Just let me know what blocks and what positions to run.

 

[burpod]

i wouldn't want graphs, i would just want the .csv files . to see the numbers. graphs are pretty meaningless on their own other than to say "something's F'd up"

 

[Winning]

people in old threads saying what timing to use is kinda meaningless tho

I get that but it was something i had not tried. Also oddly seemed to help alittle and really improved power band.

 

[Winning]

i wouldn't want graphs, i would just want the .csv files . to see the numbers. graphs are pretty meaningless on their own other than to say "something's F'd up"

What blocks would you like me to record while the shudder happens. I only took photos of the graphs. But i could make logs tomorrow. Should I set the timing between 2-2.5 first. Any specific timing i should aim for here as a starting point?

 

[burpod]

my recommendation would be set it to +0.5-1.0 and go from there. logs on a stock tune to take would be - in TURBO mode - 011-001-004

 

[BobnOH]

I followed you link and found the torsion value in the thread should be 4.9 or so. Mine is currently at 0 untill warm then it is 0.5. I was under the impression it should be 0 to pluss or minus .5......snip........

My apologies, you are correct. I simply did a search. That thread does not seem good for diagnostic of the crank and cam sensors.

 

[Winning]

Ok put the torsion vlaue back to .5.

 

[Winning]

My apologies, you are correct. I simply did a search. That thread does not seem good for diagnostic of the crank and cam sensors.

Thanks for the responses. I still found a bunch of usefull threads to read with that google shearch tool and setting the tosrion to 4.9 was informative. And really did seem to improve the powerband range. I set it back to .5. I also had forgotten how little a movement on the cam gear can effect the torsion value. Like the difrence between .5 and 4.9 is about 3mm. And nonvisable movemets can cange it over 1.

 

[Winning]

my recommendation would be set it to +0.5-1.0 and go from there. logs on a stock tune to take would be - in TURBO mode - 011-001-004

I sent you a log with the torsion value still at 4.9. I noticed the group four injection start specified value jumps close to the time that the shudder happens. It also jumps with the torsion value set to .5.