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TDI 1Z keine Leistung mehr! V max 140 km/h! Boost pressure is good!
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colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
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Location: Husum.
Verfasst am: 16-09-2008 21:18 Titel: TDI 1Z keine Leistung mehr! V max 140 km/h! Boost pressure is okay!
Hello everyone,
I'm having a serious problem with my Passat (engine code 1Z). Suddenly, I have no power throughout the entire RPM range, starting around 2000 revolutions. It feels very sluggish, as if someone is lightly braking all the time. Additionally, it starts to jerk at certain RPMs, for example, at 1250 revolutions (regardless of whether it's in 2nd, 3rd, or 4th gear). If you increase the RPM, it runs smoothly again, but it's extremely sluggish when accelerating. The maximum speed is now only 140 km/h; going uphill reduces it to about 120 km/h. The engine idles perfectly smoothly (900 revolutions). Also, there's no more excessive smoke than usual for a diesel engine.
Since I attributed the problem to boost pressure, I had a friend read the error codes today using VAG COM (no errors were registered). We then checked the EGR system, and everything was fine: the valve, pressure sensor, hoses, etc. We also checked the entire turbocharger system, and everything seemed okay there as well. Afterwards, we did a test drive. The boost pressure built up consistently; it was 1.0 bar at idle and reached a maximum of 1.9 bar (or slightly above) at high RPM, with no overshoots or drops detectable, even when the engine started to stutter (although power was obviously lacking despite the good boost pressure). The top speed was 130 km/h. For your information, I've already replaced the mass airflow sensor and the solenoid valve that controls the boost pressure, but it hasn't made any difference other than costing me a lot of money.
Nothing was done to the timing belt; it's still tight, and the crankshaft bolt is already the newer one with a strength rating of 12.9.
What could be the cause of this sudden loss of power? The diesel filter and air filter have been replaced every 30,000 km. I never use biodiesel.
"Could my ESP system be damaged? Or what could be the cause? Has anyone else experienced something similar? Please help me." Also, perhaps the mileage is a factor; it's 315,000 km.
Arne.
guste100
Professional mechanic.
Registration date: July 27, 2004.
Posts: 854
Karma: +4 / -0
Location: Central Schleswig-Holstein.
1997 Volkswagen Golf
Posted on: 2008-09-17 15:04
Title:
Generally speaking, using VAG-COM makes it much faster and easier to find the error. Whether the investment of approximately €70 in the simplest version is worthwhile compared to the usual amount of work required is something each person must decide for themselves. The fact remains that we can hardly help you without further data or checks from your side.
Let me preface this by saying: The final speed of approximately 140 km/h strongly suggests a limp-home mode. In that case, there *must* also be an error code stored in the engine control unit (ECU). I would therefore highly recommend having the ECU read again and paying close attention to the results. It wouldn't be the first time that a workshop clears the codes, then re-reads them without a test drive and finds no errors.
I haven't come across a motor that consistently only reaches 140 km/h without the engine management system going into limp mode or storing error codes (although I don't have a huge fleet of vehicles to maintain). However, if such a problem exists, it must be very significant and therefore quite obvious.
The following points are not relevant to me:
- Difficulty in operation (e.g., brakes sticking), which would cause them to overheat during power reduction.
- Compression (because at least one cylinder must have zero compression, which is noticeable even when idling), it's unlikely that all of them are worn out to the same extent.
- Air in the diesel lines (would cause issues like delayed fuel injection and starting problems, which would be recorded in the error memory).
- Turbo failure (error code).
- LMM failure (error code).
- Intercooler leak (detected by diagnostic system).
Possible causes for me include:
- ESP malfunction and delivering a drastically insufficient amount.
- Air intake/exhaust obstructed.
It's questionable whether a timing belt misalignment would necessarily cause further errors, or whether that possibility should still be considered.
Regards,
Sure.
colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
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Location: Husum.
Written on: 2008-09-17 17:44
Title:
Hello.
Okay, besides one error related to a resistor in the airbag system, nothing else was found. My friend read the codes and then cleared them. However, I'll try to get access to VAG-COM myself and then attempt to provide you with the relevant data. In the meantime, that's all I have.
Best regards, Arne.
Please provide the German text you would like me to translate into English. I will then give you only the translation, without any explanations.
Passat 35i TDI, engine code 1Z.
colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
Karma:
/ -0
Location: Husum.
Written on: 2008-09-20 22:46
Title:
Hello.
I've been looking into VCDS (VAG-COM) lately. My question is: Do I need the full, expensive version to log the parameter blocks (ESP injection quantity) on my older Passat 35i, TDI, with engine code 1Z? Or can I do it with the shareware version of VCDS, or do I need a separate tool (like a VCDS scope)? Does my old car require an expensive interface (e.g., for €249) with the full version, or is a cheaper interface sufficient, along with a shareware version of VCDS? Is there another way to access the full version without buying the interface?
Someone wrote to me that the simplest version costs 70 euros.
I'm new to this topic, so please don't immediately question everything I write. I would be grateful for any help.
best regards, arne.
Please provide the German text you would like me to translate into English. I will then give you only the translation, without any explanations.
Passat 35i TDI, engine code 1Z.
LZ
Overalls.
Registration date: 09/01/2003.
Posts: 134
Karma: +6 / -0
Location: .at-Klbg. (This likely refers to a specific region or district within Austria.)
Written on: 2008-09-21 11:18
Title:
Which diagnostic system is the right one for VAG vehicles?
http://shop.dieselschrauber.de/VCDS-Fahrzeugliste.pdf
That would be great! / That's perfect! / That would do it!
Generally, feel free to browse around here
http://shop.dieselschrauber.de/.
The forum administrator = shop owner.
Best regards, Robert.
Please provide the German text you would like me to translate into English. I will then give you only the translation, without any explanations.
Golf3/1Z Estate (Variant).
nedoh90
Registration date: October 11, 2008.
Posts: 1
Karma: +0 / -0
Written on: 10-11-2008 22:38
Title: vacuum lines
Check the hose that runs from the control unit to the intake manifold. I had a similar problem, and there was no error code stored, but my car could only reach 140 km/h. In my case, it was the hose for the boost pressure sensor.
guste100
Professional mechanic.
Registration date: July 27, 2004.
Posts: 854
Karma: +4 / -0
Location: Central Schleswig-Holstein.
1997 Volkswagen Golf.
Written on: 2008-10-15 7:53
Title:
I read the data from the Passat owned by the person who started this thread last night.
Problems / Diagnoses:
- Power loss across the entire RPM range.
- The perceived performance is approximately half that of a standard single-cylinder engine.
- The maximum speed is below 140 km/h.
- Rare and irregular jerking motion (approximately once per minute), independent of engine speed and load.
- Timing belt is very loose, but shows no visible signs of wear.
- no visible smoke (which indicates a significantly reduced actual fuel injection amount).
- Idling is generally smooth, with only occasional slight jerks.
The error memory showed only... (followed by what it showed).
17978 - Engine control unit locked.
P1570 - 35-10 - - - Intermittent.
The error didn't reappear after I deleted it.
The log is available in
https://community.dieselschrauber.org/en/viewtopic.php?p=138085#138085, both as a formatted .xls file and as a .csv file.
The timing belt was only tightened and not properly adjusted (which is a shoddy job, but the owner requested it this way due to the late hour).
I don't see any explanation in MWB 1 for such a drastically lower actual injection quantity.
The timing belt will be correctly adjusted by the thread manufacturer over the weekend.
Now my question: Could the timing belt actually be the only problem?
I suspect that the problem might not be solely due to the timing belt. I'm even unsure whether a misaligned timing system could actually be responsible for such a significant power loss (50%). However, if it were "only" a misaligned timing system causing the 50% power loss, I would expect massive smoke and error messages related to the fuel injection control. Therefore, I believe the ESP is likely defective.
What do you think?
Regards,
Sure.
colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
Karma:
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Location: Husum.
Written on: 2008-10-20 19:35
Title:
Hello diesel mechanics,
I found the problem. It was the pressure springs in the high-pressure section of the pump. The damage looked similar to what was described in the technical article on this topic. Each pressure spring had broken into three pieces. However, I didn't see the same kind of stress marks as shown in the article. The inner walls of the pump were still smooth. The symptoms were similar to those reported by the author of the article.
- The maximum speed was decreasing progressively, starting at around 140 km/h, then dropping to 130 km/h in the 4th gear, and finally only reaching 110 km/h in the 5th gear.
- Absolutely terrible acceleration; you feel like you're only using half the power.
- In the initial stage, the engine ran smoothly at idle without any hesitation. However, later on, it also started to hesitate during idle.
- No increased consumption, no soot.
-In the final stage before repair, the car would only start after a long cranking if it had been left standing for a while. Once it started, you could turn it off and it would restart without any cranking.
- No unusual error messages were detected when using VAG-COM.
- The values in the measurement blocks were all within the normal range (see log). No anomalies detected.
Best regards, Arne.
Please provide the German text you would like me to translate into English. I will then give you only the translation, without any explanations.
Passat 35i TDI, engine code 1Z.
colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
Karma:
/ -0
Location: Husum.
Written on: 2008-10-23 17:13
Title:
Hello.
Here's another tip: If you suspect that the pressure springs in the pump are causing a problem with your TDI, there's a relatively easy way to check. Remove the timing belt and see if you can easily turn the pump drive gear by hand. If it turns freely without resistance, there's a high probability that the springs are defective. The broken springs no longer provide counter-pressure on the plunger inside the pump. If the springs are intact, you should feel significant resistance (almost impossible to overcome by hand) four times as you rotate the pump gear completely (corresponding to the four camshaft lobes acting on the plunger).
Just a tip, this is how it was for me at least. The fuel pump was a VP 37 from a Passat TDI 1Z. But I think the pumps are all built in a similar way.
Please provide the text you would like me to translate from German to English. I will then give you only the translation, without any explanations.
Passat 35i TDI, engine code 1Z.
Last edited by colt-seavers on October 28, 2008 at 2:49 AM, with a total of 1 edit.
I'm sorry, I don't have enough information to do that. Can you please provide more context?
Overalls.
Registration date: 2005-10-03.
Posts: 58
Karma: +2 / -1
Location: Lake Constance.
Written on: 2008-10-24 7:53
Title:
Thank you for the feedback. Did you receive the springs individually and have you already installed them? Is the car running like it did before? It's interesting that no error is being detected, but the 1Z system is just too old for that... We could implement a plausibility check between throttle position and air mass flow or something similar...
Greetings.
Luesken.
colt-seavers
Overalls.
Registration date: September 16, 2008.
Posts: 8
Karma:
/ -0
Location: Husum.
Written on: 2008-10-24 12:13
Title:
@
luesken
Hello.
Okay, so I completely reassembled the car yesterday; it took about 2 hours with everything (I'm a pretty slow mechanic, but I'm thorough). The car is running great again. I installed the pump in the same position as before. Before disassembly, the injection timing was at 3 degrees BTDC (Before Top Dead Center), now it's at 0.6 degrees BTDC. However, the engine still runs really well. I got the springs individually from a Bosch service center as a repair kit; they cost €11.20 plus VAT. The O-ring can be replaced separately and costs €2.52 plus VAT.
Best regards, Arne.
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