Touran TDI: Speedometer limited to 180 km/h after head replacement

Hello everyone,

I'm not sure if I'm in the right place; after reading it once, I thought I was dealing with professionals here . Unfortunately, I have a problem.

My car: Touran, manufactured in 2004, 6-speed, TDI 2.0, 120,000 km, engine code AZV, 100 kW.

The car drove great, and the speedometer showed a top speed of just under 210 km/h on a straight road.
In 2008, I had to top up the coolant 2-3 times.
After doing some research online, I found out that it might be a faulty cylinder head.
The diagnosis at VW, after a day of testing, was a minor water leak in cylinder 1.
Subsequently, the cylinder head was replaced.
"Because it was due, I also had the timing belt and water pump replaced. Additionally, the turbocharger hoses were replaced due to a slight leak. The brakes were also completely renewed at the front, and a complete inspection was performed."

Result: - €3000 poorer - The car can only go 180 km/h now. - Even going downhill, where I used to reach 220 km/h, it's difficult to exceed 180 km/h.

One week later, I was back at the VW workshop - the result was that everything was fine. They had installed a software update, and it should now work.

Es war leider immer noch das gleiche. Maximum speed: 180.

Back at the workshop, a message was sent to VW - the response was to check the catalytic converter.

The KAT (diagnosis system) check was performed and everything was okay. Then, the technician called, happily reporting that a pump injector element was defective, which was the reason for the lack of power at the top speed.

Here are the readings I obtained: Cruise control 1: 0.45 mg/H / 2: -0.42 / 3: 0.00 / 4: -0.02. Comment: Yes, the 0.45 is much too high. Although the target value is -2.8 to 2.8... Further values: Motor speed: 810 rpm, target: 860-940 rpm.

"The PD (fuel injector) was replaced, but I'm still €650 poorer, and the car still has a maximum speed of 180 km/h. The next day, I went back to the workshop, where a VW remote diagnosis was performed, and the values of the PDs were checked again. The result was that PDs 2 and 3 are also now defective."

Tomorrow, the glow plugs will be replaced to see if they are actually defective, or if the problem lies with the cylinder head. The wiring harness will also be replaced. Now, I can already guess what's going to happen next...

Now, my question to the experts:

Is it realistic that a fuel injector would fail during a test drive at the workshop, and then, just one day after installing a new one, two more injectors supposedly fail, even though they were perfectly fine before? Were the readings really indicative of a defect? Are these components sensitive, and could there have been negligence during the installation of the cylinder head?

Is it even realistic to think that this might have something to do with the final speed?

The VW workshop always says it can't be related to the timing belt replacement, but could it be?

Since I'll probably be back in the workshop tomorrow, and I'm not a diesel mechanic , I would appreciate any tips/information.

Thank you.
Nicolai.

Quickly: Use the search function and, if possible, switch workshops.

There are many opportunities to make money, perhaps too many for a beginner (incomplete).
- Adjustment of PD elements,
- Timing belt and timing.
- Insufficient air mass flow due to various reasons.

The PD elements were replaced unnecessarily, but the values for the idle speed control were excellent.

Best regards, Rainer.

I would confront the master technician about why the 0.45 value in the idle speed control is considered too high. As Rainer already mentioned, the values are excellent. I would demand a refund for such a diagnosis. Why should I pay for the PDE (presumably a diagnostic fee) if everything was fine, just because the master technician doesn't know what he's doing? It's not clear to me.
I would definitely switch workshops. Apparently, they don't know what they're doing.

Hello,
My condolences regarding the workshop event. It seems you reported it a little too late!
The fact that the LD hoses have been replaced makes me suspect that the lack of maximum speed (Vmax) is largely due to this: he's not getting enough air, for whatever reason. Of course, the low LL value should also be considered. However, the way they're approaching this seems to rule out none of the possible assembly errors. Or perhaps they're trying to prevent the inevitable closure of the workshop by exploiting their customers.
haithamina

I can only shake my head at so much incompetence. Are good workshops really that rare?
I've been to 5 different workshops, and in each one, I experienced at least one major blunder.

Just a tip: Don't pay for anything that they did wrong.

That's the most outrageous thing about them. They're even getting paid for their incompetence...

Thank you for the information.

Okay, I just received the diagnosis from the CEO:

Apparently, the three additional piston rings now suddenly have scratches because they supposedly got stuck in the old cylinder head...??

The new cylinder head is also defective; something has broken off, so it will be replaced again...

"Regarding the three other glow plugs, I wouldn't install them because they have some play and could potentially damage the new cylinder head. Should we install three new ones or reuse the old ones? He couldn't explain why the scratches hadn't been noticed before. He's now consulting with the master mechanic, also about the values of the first glow plug, which were initially fine, but according to the master mechanic, those values indicate a defect."

I went to that workshop specifically because they had such good reviews online... absolute garbage.

Question: Would you reinstall those three old PDs? Could that be compatible with the "Einfresse"?

Okay, here's the translation:

"By the way, does anyone know of a good, reputable independent garage in Cologne that could handle this problem, and that actually knows what they're doing?"

After hours of discussions:

I received the wrong test sheet, specifically the one used after the exchange. Before the exchange, the value above the PD (positive displacement) on cylinder 1 was over 3, which likely indicates a malfunction.

The other three piston rings show signs of wear, caused by the new cylinder head. Comment: The old parts had worn down due to the engine's mileage of 120,000 km, and now, with the new cylinder head, they no longer fit properly, resulting in wear marks on the rings, which will likely cause them to fail soon. VW refuses to cover any of the costs in this case.

Great, right? You pay money for a more expensive cylinder head, and you don't get any goodwill because you once had the inspection done at ATU. This cylinder head is causing problems with the PD elements. It's outrageous. VW should take responsibility for this and point it out. Then I wouldn't have had the cylinder head installed and would have kept driving until it really broke down.

According to GF:
In addition, something was broken on the new cylinder head, which meant that even with the new PD element, it couldn't reach its maximum speed. I'm getting the three PD elements, including installation, at a friendly price from company 823, net.

I have a guarantee from the manager that the car will reach its maximum speed again after the replacement... otherwise, I won't pay for it.

I'll let you know how it turns out.
Greetings.
Nicolai.

I agree with Rainer... they should check the timing belt again.

Okay, so this whole thing about valve stem seals is complete nonsense. They should take a look at a 1.9 TDI engine with 230,000 km and see how the valve stem seals have eaten away at the head. It looks really bad, but the engines still run. Even the 16V valve stem seals are secured with two screws in the head to prevent them from leaking so badly. So what's the deal with the valve stem seals being stuck in the new head? For me, this is the last time I'll go to this workshop. Thankfully, I always do my own work.
'Could you please find out exactly what happened at the ZK and let me know? I'm curious.'

Okay, to summarize: The old piston rings had become worn and embedded in the old cylinder. Now, a new cylinder is being installed. Due to the wear and the movement during installation, the old piston rings have been slightly deformed. This slight looseness causes the piston rings to wobble slightly within the new cylinder. According to the service manager, the initial result is visible scratching. In the near future, this wobbling could cause the piston rings to leak, and subsequently, the new cylinder could also be damaged.

Unrealistic? I once told the manager something similar because he's now paying significantly more due to the repair... so he doesn't benefit from me telling him that.

I'm asking again about what was broken.

ahaaaa, PDEs that deform??? I'm literally dying of laughter right now .
You can see a slight aluminum abrasion on the injectors, but that's perfectly normal. It has nothing to do with whether the injectors are new or old. If you get a new fuel pump and 4 new injectors, you'll have the same abrasion again after 1000 km. The workshop should explain to me how an injector made of STEEL can deform inside a fuel pump made of ALUMINUM .

It's true that PDEs 'wobble' a bit in the head, but the area where the O-ring makes contact in the ZK remains unaffected. The O-ring always rests on a good and clean surface. There will be no leaks. Okay, if there are imperfections as small as 0.5mm in the ZK, then yes, but you are still very, very far from that }.

For me, the workshop simply doesn't seem to know what they're doing. That's it.

NicolaiKoeln wrote:

I received the wrong inspection sheet, specifically the one issued after the replacement. Before the replacement, the value above the PD (presumably referring to a pressure drop or similar measurement) on cylinder 1 was over 3, which likely indicates a malfunction.

Did you notice anything unusual while driving? Like an unstable idle, similar to an old tractor, for example?
For example, this kind of issue can sometimes be caused by a problem with the pressure differential valve (PDE), where it has become so ingrained that the seal is no longer tight. This does happen. In such cases, the problem is with the head, not the injector.

It's as EMS states. Typically, the pump body of a PDE (Positive Displacement Element) works its way into the head, rather than the other way around, specifically above the sealing rings. Aside from the unsightly appearance, this doesn't have any significance because it's above the sealing surfaces. The head is made of aluminum, and the pump body is made of cast iron.
The problem with the lack of power is likely due to gradually shifting valve timings, or possibly the broken part. It would be interesting to know which part it was. I agree.
If they install another new head, they will notice the issue with the valve timing and correct it.

If they put on another new head now, they will notice the problem with the valve timing and fix it.

'Exactly, and then it says: 'You see, it was all the fault of the Central Committee, just as we said.''

Quote:

If they put on another new head now, they will notice the problem with the valve timing and fix it.

Hopefully... wasn't there a movie about that? Something like "You Don't Know What You're Doing" .

"Just to make sure Nikolai understands this better:"
You can't ignore idle compensation values of 3 mg per cylinder. The engine is running very unevenly at idle, similar to a Lanz tractor. You can hear that immediately, even without being an expert. Furthermore, this will lead to more or less serious problems during operation, depending on the exact cause of the high compensation values.
I'm saying that, if the Touran was running smoothly before the visit to the workshop, you can assume that the fuel injection system was within acceptable parameters, and that the high deviations only occurred after the intervention. This would then clearly indicate who is responsible for the injector pump issue.
There could be various reasons for this. For example:

-Incorrect default setting.
-misaligned PDE
- Seals damaged during installation.
-Thread detached from the tensioning block.
-PDE sustained damage during the renovation.
etc. (there are other possibilities as well).

Unfortunately, I can only explain the technical aspects. I have no particular knowledge of legal matters. So, I'm afraid your money is likely lost. However, please let us know how the situation ultimately resolves.