VW Golf TDI: Repair Costs Ruining Me?

Hello everyone,
First of all, I would like to introduce myself.
My name is Rainer, and I'm from North Rhine-Westphalia (NRW). About 13 years ago, I trained as a car mechanic. I've been reading your forum for a long time now, mostly because the problems I've been having with my TDI led me here *g*.
The whole ordeal started when I bought a VW four years ago. After only owning the car for a week, I discovered that the entire parking space was covered in diesel fuel. The previous owner had been using biodiesel, which, according to the manual, he was allowed to do (the car was then 2.5 years old with 72,000 km on the odometer).
Well... the fuel injection pump is broken. I sent the part to Bosch for repair, they sealed it, and I installed it back in the car. Now, the engine doesn't start properly when it's cold. A new pump was installed... great!
R109 was also something I used to do occasionally.
'Things were okay for a while, but the problems with the fuel injection system continued. It was replaced four weeks ago. The car starts poorly when it's warm, and I've been constantly going to the workshop. They seem to be at their wit's end. They've already replaced the temperature sensor and starter motor, and supposedly adjusted the fuel injection pump, but nothing seems to work.'
'Now, supposedly, they found a fault starting on Monday: A hose on the turbocharger was damaged. Great...fault found. My wife picked up the car, and since then, it's been going into limp mode at a certain RPM. We took it back to the workshop, and they told me the turbocharger is faulty. When I inquired with Bosch, they said it could be due to a valve issue. They claimed they had never encountered problems with their turbochargers before. What do you think? What are the most common causes for this kind of problem? I've found quite a bit in the search function, but I haven't seen anything about issues arising after replacing a hose. The hose was definitely leaking. I can't believe the turbocharger is faulty. I suspect it's more likely to be the valve. Or could it be that the issue with the turbocharger only becomes noticeable when it reaches full pressure?'
I would really appreciate your responses.
Regards:
Rainer.

P.S.: The car has 170,000 kilometers on the odometer.

Hi Rainer, welcome to the forum.
That Golf AFN is a great car. It's a shame that it was ruined by the biodiesel issue.
Regarding your problem: Please search this forum for 'difficult to operate' + 'VTG'.

You should be able to find it there...

bonze wrote:

My wife picked up the car, and since then, it always goes into limp mode at a certain RPM. I took it back to the workshop, and they told me: "The turbo is broken." When I inquired with Bosch, they said it could be due to a valve. They had never encountered this problem with turbos before. What do you think? What are the most common causes for such a problem?

-> VTG, difficult to operate.

-> Faulty charge pressure control valve / thin control hose to the VTG (Variable Turbine Geometry) unit leaking / detached.

-> Vacuum hose from the intake manifold to the sensor in the engine control unit is leaking/disconnected (on a VW Golf Mk3).

This likely covers about 90% of all such problems.

Thank you for your quick responses. It's probably true that the biodiesel more or less ruined the car. Unfortunately! While a faulty mass airflow sensor (MAF) can be dealt with, this whole mess with the fuel pump has really taken its toll on me. The problem with the MAF wasn't immediately recognized either. Regarding the fuel pump, it was even removed and checked again (for 160€). I think I've probably already paid at least 160€ just for reading the error codes.
I hope that, in my case, it's really just the valve. I'm going to make an appointment with Bosch and have them check it out. VW definitely wants to sell me a new turbocharger (costing €705).
Thank you for sharing your opinions with me.
I don't think the problem with poor starting when hot has been solved by the valve or turbo.
The main thing is that the car starts pulling again.
Werde das Auto wohl verkaufen wenn er wieder anständig läuft. Da ich Stellenweise bis zu einer Minute Orgel denke ich, dass es vielleicht an den Düsen liegt. Was ist das nächste? Kat? Nein Danke....Leider hat VW dieses Auto versaut weil Sie es für Biodiesel freigegeben haben. Mittlerweile haben Sie es eingesehen und intern die Freigabe zurückgezogen. Das nützt mir aber nichts. Damals wurde mir die Kulanz für die Pumpe aberkannt, da der Vorbesitzer einmal hat einen Oelwechsel an einer Tankstelle außerhalb der Wartungen hat machen lassen und jetzt ist es verjährt...Somit sind in etwa alleine nur durch den Einsatz von Biodiesel des Vorbesitzers auf mich 3000€ Kosten gekommen. Das stimmt mich traurig und diesbezüglich ist meine Meinung in der momentanen Situation leider nicht gut über den Konzern VW. Sorry!

P.S.: Just remembered something.*g*:
Since the workshop had exhausted all its options regarding the starting problem, they essentially told me:
Either they continue to live with these problems, or we keep searching, and then it will become very expensive for you!
'I can only say that's great. Excellent customer service, but maybe it's just the workshop... I don't know.'

P.S.: Just remembered something.*g*:
Since the workshop had exhausted all its options regarding the starting problem, they essentially told me:
Either they continue to live with these problems, or we keep searching, and then it will become very expensive for you!
'That's great,' I say. 'Great customer service, but maybe it's because of the workshop...I don't know .'

Hmm, it seems like a great club...

Have you ever looked into a technical article about poor starting performance in warm engines? The main reason is usually a worn-out (low-capacity) battery. Has anyone on your team dealt with this before? VW has a great device that connects to the battery and displays the capacity in %.

P.S.: Just remembered something.*g*:
Since the workshop had exhausted all its options regarding the starting problem, they essentially told me:
Either they continue to live with these problems, or we keep searching, and then it will become very expensive for you!
'That's great,' I say. 'Excellent customer service, but maybe it's because of the workshop...I don't know .'

Hmm, it seems like a great club...

Have you ever looked into a technical article about poor starting performance in warm engines? The main reason is usually a worn-out (low-capacity) battery. Has anyone on your team dealt with this before? VW has a great device that connects to the battery and displays the capacity in %.

Hello Julian,
Believe it or not: no!
Your comment was: 'The starter motor is working well...'
The battery is the first one. So far, no problems, although the organ possibly damages it as well... therefore, a new battery might also be provided to me .

The temperature sensor for the starter motor has already been replaced (I think it's ridiculous to make starting the engine dependent on its temperature).

I once read something about a problem with the nozzles related to shutting them off or something. Could it be that there are also late effects from biodiesel?

Hi Bonze,

First of all - welcome.

Regarding your battery – if that's the issue, it can be quickly tested.
Find someone with a good battery, and use a thick jumper cable – every diesel mechanic should have one (to help women whose car batteries are dead...).
Connect the batteries, keep the second car running at a slightly higher RPM (2500-3000), and then try starting your car. If it starts immediately, replace the battery.

If that's not the problem - mine was also quite reluctant at one point - the cause was air in the fuel line due to sloppy DIY work. The fuel system in the AFN engine uses vacuum and is very sensitive to leaks. (If that *is* the issue, you might also end up damaging your fuel injector control valve because pressure fluctuations occur in the pump.)

By the way, Audi always does the diagnostic scans for free here, while...
Absolutely Totally Incompetent.
'for which they charge €20.'


Incidentally, I didn't initially notice the leak; it just drew air as soon as it was upright, and the ESP system remained empty. Then, before starting, I pressurized the ESP system using a fuel pump, and sure enough, it immediately started working. This indicated two possible issues: either the ESP unit itself is leaking or not functioning correctly, or there's an air leak in the supply line.

After I had the supply line open once, this cause immediately became obvious, and that was it. By the way, your supply line was also open due to the pump replacement!

Hello Julian,
Believe it or not: no!
Your comment was: 'The starter motor is working well...'
The battery is the first one. So far, no problems, although the organ possibly damages it as well... therefore, a new battery might also be provided to me .

The temperature sensor for the starter motor has also been replaced (I think it's ridiculous to make starting the engine dependent on its temperature).

I once read something about a problem with the nozzles related to shutting them off or something like that. Could it be that there are also late effects from biodiesel?

'Pathetic... these idiots aren't even trying the cheapest method. What a bunch of losers.'

Testing a new battery... if it's still the original one from 1997!

bonze wrote:

The temperature sensor for the starter motor has already been replaced (I think it's ridiculous to make starting the engine dependent on the engine temperature).

"Temperature sensor for the starter"
I don't recognize this part.
If they are referring to the water temperature sensor, then it has something to do with the fuel injection start quantity. This may also explain your problem with starting the engine when it's warm. By the way, the technical article also mentions that the starter motor sometimes doesn't provide enough starting speed, which prevents the warm engine from being started. If the water temperature sensor is disconnected, the warm car often starts immediately.

Apparently, the workshop association is at odds with the current technology. I hope they don't have to repair a PD (presumably referring to a specific device or system) anytime soon!

Regarding the poor starting issue, I can tell you how I discovered the cause: Under typical bad-starting conditions (engine properly warm, and parked for about 5-10 minutes), I waited on a slight downhill slope for those 5 minutes and allowed the car to roll forward with just a minimal jolt. The result was surprisingly good. What did I do? I didn't buy or replace anything; instead, I removed the starter motor and lubricated all moving parts (which actually looked very good despite appearances). Then, I carefully soldered all cable connections that carry the starting current, and cleaned the contact surfaces on both the cable terminals and their mating points (e.g., the transmission).
That was about two years ago, and it was a complete success. Before that, my wife had been too afraid to go into the city due to concerns about being harassed.
The test is easy to take, and you might rediscover the joy in your actually brilliant AFN (presumably referring to a hobby or activity).

Best regards,
Andreas

Good evening everyone.
Thanks for the numerous responses. Back in my day, about 13 years ago (I'll admit it: I learned at Ford and probably owned around 8 of them)*g*, there were no problems with the diesels. They were loud and smelly*g*. The only issues back then with the 1.6 or 1.8 diesel engines were occasional oil scraper rings and needing to adjust the valves (maintenance), which sometimes involved using shims. However, there wasn't much electronics and turbos weren't common.
My wife likes/liked VW cars, and we needed a car suitable for a family. She didn't want a Ford. Unfortunately, I had to sell my XR3i convertible (I bought it specially from Munich), and we needed a family car. Since we were planning to move and I had about 50 kilometers (one way) to commute to work, a diesel was the only option. My brother used to drive a Jetta Diesel (until rust got the better of it) and thought diesels were great. I laughed at him back then!

Meanwhile, I say:
If I were to get one, it would be a diesel with a tow hitch and as a station wagon! It should have good torque, be fuel-efficient, and inexpensive to maintain (at this point, sorry: lol).
Since I always seem to get the short end of the stick in life, it's pretty much guaranteed that things are completely messed up for me in this situation.
The fuel pump (related to the difficulty starting) can't be the problem because it was checked by Bosch in January.
'My colleague, who works at Volkswagen, said the exact same thing: there's a pressure loss in the pump.'
That's why the verification is necessary.
Five weeks ago, when he told me again: 'No, it's the pump,' I called Bosch and demanded to speak to the CEO. I told him that Volkswagen was in a very difficult situation, and if it turned out that the problem was indeed with the pump, I would forward Bosch the invoices from Volkswagen, which Bosch would then have to pay.
He became very calm and called me back, almost guaranteeing that the pump is in good working order based on the results.
Regarding the temperature sensor:
Ich stelle mal die frage: wozu braucht ein Fahrzeug einen Temperaturfühler um die Drehzahl eines Anlassers nach Betriebszustand zu Regeln bzw. diese Werte an das Steuergerät weiterleitet? Einzigste Erklärung für mich: VW hat an anderen Modellen gemerkt, dass der Anlasser des öfteren an Vorgänger Dieselfahrzeugen Probleme macht. VermuSure, here is the translation of the text from German to English:

'I'm so excited!!'

Regarding batteries:
Unfortunately, I don't understand why a car starts easily when it's cold, but struggles to start when it's warm, even though the problem is supposedly the battery. I can't quite grasp how the battery could be the issue, since the engine should theoretically turn over more easily when it's warm.
But I definitely don't want to deny that! I'll look into it further, but based on the logic of things, I would say it doesn't fit.

Finally, in this incredibly long post:

I'm not saying that the car didn't bring me joy. It's a great car with fun driving characteristics (that's why I specifically wanted the 110 horsepower version, not the 90). However, VW ruined it by approving its use with this awful biodiesel! Back then, they wouldn't grant me any goodwill because the previous owner had an oil change done outside of the regular inspections at a gas station. Now, VW isn't granting me any goodwill either, claiming that the warranty has expired, even though they withdrew the approval for the biodiesel (which I only recently learned about). In my opinion, they ripped off their customers: First, they received subsidies, and then, unlike other manufacturers with similar components, they used it as a marketing tool to attract environmentally conscious buyers. This was done at the expense of customers who bought vehicles that already had 70 or 90,000 kilometers on them. I am in contact with 'Auto Bild' regarding the biodiesel issue, and I hope that, since I can't take legal action anymore, I can at least warn other customers based on my experiences, which I will also share here on my page.

http://www.feldinethome.de/Tortur.htm

can be found there.
Unfortunately, there's a powerful lobby behind biodiesel, and they even want to mix it with regular diesel fuel. Congratulations... (said sarcastically).

bonze wrote:

....Ich stelle mal die frage: wozu braucht ein Fahrzeug einen Temperaturfühler um die Drehzahl eines Anlassers nach Betriebszustand zu Regeln bzw. diese Werte an das Steuergerät weiterleitet? Einzigste Erklärung für mich: VW hat an anderen Modellen gemerkt, dass der Anlasser des öfteren an Vorgänger Dieselfahrzeugen Probleme macht. VermuSure, here is the translation of the text from German to English: "I'm so excited!!"

I already explained that above. That circuit doesn't exist! The workshop told you nonsense.
The temperature sensor regulates the amount of fuel needed for starting (not the cranking speed). It requires more fuel when cold than when warm.

Quote:

Regarding batteries: I'm sorry, I don't understand: Why does a car start easily when it's cold and everything is difficult, but starts poorly when it's warm, even though the problem is supposedly the battery? I can't quite grasp why it would be the battery, since the engine should theoretically turn more easily when it's warm.

A warm engine has a harder time cranking over than a cold one. The pistons have less clearance in the cylinder bore when they are warm.
If the battery is weak and can't provide enough power to spin the starter motor at the required speed, you'll need to crank it. However, the starter motor itself might also be difficult to turn (which happens very frequently). The effect is the same. "98_alh" described this well.

Bertil wrote:

A warm engine rotates less smoothly than a cold one. The pistons have less clearance in the cylinder bore when they are warm.

Objection:
I had a similar issue with the AFN (the engine started somewhat hesitantly, taking about 1 second to start), and I compared the starter motor speed at top dead center (TDC) using an oscilloscope, both when it was cold and when it was warm.
The starter motor began to spin a little faster.
(My post should be findable somewhere here.)

IMO, the initial amount of "warm" (presumably referring to a setting or parameter) is being overly restricted by the software.

I've explained to myself that the poor cold start performance with higher starter motor winding resistance leads to less power and lower RPM, especially at higher temperatures. However, this contradicts Ulf's measurements. The battery actually has a relatively small influence; in fact, it might even be easier for the battery under these conditions. Changing the starting amount had no effect.

Best regards,
Andreas

ulf wrote:

Bertil wrote: A warm engine runs less smoothly than a cold one. The pistons have less clearance in the cylinder bore when they are warm. Objection: I had a similar issue with the AFN (the engine started somewhat hesitantly, taking about 1 second to start), and I compared the starter motor speed at top dead center (TDC) using an oscilloscope, both when it was cold and when it was warm. The starter motor began to spin a little faster. (My post should be findable somewhere here.)

That might be the case, but those are likely artifacts (resulting in lower compression rates when warmed up).
You can clearly see this with engines that are pushed to their compression limits. A cold engine is easily turned over by the starter motor, while when it's warm, the starter motor may not even be able to turn the engine at all.
I once replaced the starter motor in my Jetta for no reason. After the emissions test, the (newly rebuilt) engine wouldn't start anymore. At the time, I also assumed that a warm engine would offer less resistance... but then I was enlightened by an engine builder.

Quote:

IMO is getting too hot, and the initial amount is being severely restricted by software.

That's likely the reason why bypassing the temperature sensor improves the warm-up behavior.

In this particular case, I also suspect that the starter motor's speed is too low (for whatever reason). The amount of fuel injected during cold starts is sufficient to prevent the problem from occurring, and when the engine is warm, the injection amount is too small to allow the starter motor, with its low speed, to start the engine.

I thank you for your answers. I will get to the bottom of this matter .
http://www.feldinethome.de/Frau.jpg