Timing Belt for VW Transporter T4 2.5 TDI (Pre-2000)

Hello,

Here's a small warning for everyone who owns a 2.5 TDI engine manufactured up to the year 2000 and either haven't had the timing belt replaced yet, or haven't had it replaced since 2000, or whose water pump has never been changed.

Yesterday, we almost had a serious problem... First, we detected a slight, then significant, loss of coolant. On the way to the workshop, terrible noises started, but we managed to get back to our facility.

Looking at the timing belt cover made me feel sick – thankfully, my mechanic was driving. He would have been insured if any damage had occurred.


We have already replaced the belt twice in our car (engine mileage: 260,000 km), but never the water pump.


The water pump bearing broke, which caused the timing belt to become misaligned. As a result, the belt tore through the timing belt cover over a length of 10cm, grinding and melting it in the process. The belt itself looks damaged accordingly.

It's a miracle he wasn't seriously hurt. I will send you more pictures as soon as the car is repaired and the parts are removed.



Therefore, we would like to issue a warning to everyone: please also read the relevant articles in the T4 Wiki, as they contain information about the affected vehicle identification number ranges.


Timing belt information: http://t4-wiki.de/wiki/Zahnriemen
Water pump and related defects: http://t4-wiki.de/wiki/Wasserpumpe
VAG "Death List": http://t4-wiki.de/wiki/Todesliste


I'm therefore hoping to save a few 2.5 TDI engines now... while these engines are quite robust, they usually can't survive a broken timing belt.


And hardly anyone wants to deal with repair costs of 2,000 to 5,000 euros...


Regards,
Geor.

"Water pump replacement without removing the engine - never again for me."
On my T4 2.4 with a new timing belt installed at 120,000 km, the water pump lasted only one week before it failed, resulting in a loss of power and engine seizure!
After the restart, the "best of all wives" drove another kilometer home and called me – it was shocking.
"Wapu's tilt angle is the same as yours. I'm starting from scratch again, except for the ZR EP."
Since then, see the beginning!

Yes.

I also used to believe that the workshop in town was doing shoddy work.

Since my acquaintance's car goes to that workshop, at least a high quality of work is guaranteed; there's nothing like it. I've been buying all the parts myself for my cars for several years now, and always include the water pump – but I haven't had much to do with the water pump on my father's car so far; he always took it to a workshop in our town. But that's over now; he's fed up with them.

And currently, my acquaintance is taking care of getting the bus back into working order.


I believe that until 2003, Volkswagen offered a full warranty for issues up to around 150,000 km, maybe even 100,000 km, but unfortunately, that's 5 years too late.



We experienced something similar; it started up and then stopped working, and then eventually started again... I don't know why or what caused it yet. Anyway, I felt really bad when we finally figured out WHAT the problem was. If I had known beforehand, I wouldn't have tried to start it again.

Our friendly colleague says very clearly: always use a VPN, unless the customer requests otherwise!

Quote:

Our friendly colleague says very clearly: always use a VPN, unless the customer requests otherwise!

Absolutely correct!!

It is actually irresponsible that Volkswagen and other companies do not have any regulations regarding the replacement of Wapu components (which are part of the timing belt system).

The only reason I can see is to keep the maintenance costs (which are determined for different manufacturers and vehicle types) as low as possible on paper, in order to mislead people about the actual maintenance costs.

I don't see a technical justification for this, especially since the guide rollers are sometimes constructed to be weaker than the tensioning or redirecting rollers. Furthermore, the guide roller is located in the traction area of the tensioner, which results in an even higher load.

P.S.: Anyone who specifically replaces the timing belt on these engines without also replacing the water pump is acting irresponsibly and would likely be at a disadvantage in any potential legal dispute.

To put it simply, my parents have no interest in cars; they would always drop off their car at the mechanic with a note saying, "Please do everything that needs to be done, regardless of the cost."

A perfect maintenance was expected. Well, I guess that's the end of our relationship with this workshop.


Therefore, I'm going to have our acquaintance do it; he does good work and has a reputable workshop.


Fortunately, everything turned out well this time, and it was the last belt replacement for this car – at least for us.

In my opinion, a significant reason is that the maximum tension of the new timing belt dramatically increases the bearing requirements for the pump, and older water pumps simply can't handle it. I even suspect that my pump could have lasted another 30,000 km with the old belt tension, because there was no play when I changed it, and it wasn't noisy or leaking a single drop!

Sounds logical. It was really something that the coolant ended up leaking out the way it was poured in from the top.

What I don't quite understand is why it stopped working and wouldn't restart, but then 10 minutes later it started up without any problems... except it was making terrible noises from the belt drive. We immediately turned it off after that, and then we saw what had happened.

It's hard to imagine what would happen if the belt broke.


And this is already the second unscheduled engine replacement, unfortunately. The first one was due to a leaky oil pump seal – another common issue with the 2.5 TDI engine.

"Fresser" have the characteristic of running again, albeit with noise, after becoming cold. (Also, issues related to "Grauguß"/aluminum piston pairings). Yes, I'm also familiar with the oil pump issue. Back then, I didn't attempt the repair myself and sent the customer to the dealership (with the stipulation that they should also replace the timing belt!). Guess what was due approximately 20,000 km later? The timing belt!

I'm curious to see what else will be revealed when I disassemble it tomorrow...

The problem is: anyone who switches from the old, vulnerable 18-tooth timing belt pulley to the 20-tooth version also has to replace the camshaft gear... fortunately, it doesn't cost anything.

We were lucky; the engine survived. It was finally finished yesterday. Besides a new water pump, different camshaft pulley, and a new timing belt, thankfully all that was left to replace was the timing belt cover.

It could have also turned out badly for the head gasket.

Hello again,

Our bus is now fixed and running perfectly again, except for a minor issue:

"The maximum speed of approximately 162 km/h that the car used to achieve is no longer reached; it now tops out at around 150 km/h. Our mechanic has correctly adjusted the fuel injection timing, both statically and dynamically (although it will be checked again for good measure), and otherwise, the car drives exactly as it did before."

What else could it be due to? The repair work (specifically the water pump replacement and timing belt change) was performed by a specialized workshop, and I don't think the problem lies there.

Perhaps it's a head gasket failure caused by overheating due to the water loss? But if that were the case, wouldn't there also be a noticeable drop in power and/or oil/coolant consumption, or would exhaust gases bubble into the coolant?

Regards,
George.

Okay, so...

Timing/injection start is correct... so it's becoming increasingly mysterious... does anyone have any advice?

The problem is with the climate control sensor, which is currently displaying temperatures ranging from "--- °C" to "-75°C". However, I assume this only affects the automatic climate control system and not the engine itself.

The sensor is broken; I already have the new one on hand. (Error code: Short circuit in temperature sensor to positive terminal / signal implausible).

Hi,

Take a look at the temperature values in measurement block 7 of the engine control unit.
Otherwise, in measurement block 8, when running at full throttle continuously, the limit for the transmission torque must be the lowest value.

Best regards, Rainer.

Okay, I'll look into that.

Here's what my father said yesterday: Sometimes, when driving through curves, the temperature gauge on the instrument cluster can drop from 90°C to zero, and then recover after about a minute.

There's a known issue with loose connections at the solder joints of the "Mausekino" device.
"Remove the movie player, disassemble it, resolder the connection points behind the connector - and that should fix it."