Re: Progress | Posts 16+

Markus H. wrote:

Hi, @Bertil: ...however, the pump is not misaligned in that case, and if the main timing belt breaks, the engine will be damaged...

Unfortunately, I cannot confirm that! My brother actually experienced something similar (at approximately 1200 RPM), and it resulted in the camshaft being broken into six pieces, with the rear camshaft gear completely missing!
It's good that the spare parts weren't expensive back then (1500 DM for a cylinder head), and that we managed to fix it.
By the way, the engine has reached 450,000 km , and the timing belt has broken twice (at 180,000 km + 270,000 km). Both times, "only" the cylinder head was replaced. The engine block seems to be very stable. By the way, the recommended interval for changing the timing belt was only intended for taxi vehicles , according to the workshop.

Regarding the topic:
A colleague owns one of the first 5-cylinder TDIs (Audi 100, 2.5L, 115 hp, engine code ??), and it's on its second engine block. Every time, oil leaked from the front crankshaft seal. After replacing the seal, it was discovered that the crankshaft itself was damaged (worn out) -> new engine block...

Hi,

@Bertil:
If your colleague has one of the first TDIs, then the car is likely from around 1989-90, as that's when the 2.5L TDI was introduced.
Could it even be the predecessor body style of the C4? I think they called that the 'Type 44'?

P.S.: It's amazing that your brother's engine block held up every time! No damaged pistons? On the other hand, your brother is just unlucky! He seems to have timing belt failures more often than flat tires!
Was if it was because the belt had never been replaced?

Well, anyway, I've heard from several people here about problems with the crankshaft seal (or crankshaft). I'm going to try, as Olli suggested, to include a clause in the contract stating that the engine is 'leakage-free.'

Furthermore, I have vowed to continue maintaining my own 80,000 km timing belt replacement interval.
That helped me a lot with the golf, and I think it will work well with the Audi too!

@Bertil:

It's not necessarily a bad thing if the pump is located at the rear of the engine; Audi did this with their first 5-cylinder diesel for space reasons (there was more room in the back because they also had to mount the radiator on the side), and they continued to do it that way. You could just as easily argue that it's bad that the pump on the 4-cylinder TDI (with a distributor injection pump) is driven directly by the timing belt, since that design dates back to 1976 with the first Golf 1.5D.

Best regards,

Hannes.

Markus H. wrote:

... @Bertil: If your colleague has one of the first TDIs, then the car is likely from around 1989-90, as that's when the 2.5L TDI was introduced. Could it even be the predecessor body style of the C4? I think they called that the "Type 44"?

Yes, that was the model that Audi also used to race in the US (starting number 44 - I wonder why...).

Quote:

P.S.: It's amazing that your brother's engine block held up every time! No cracked pistons? On the other hand, your brother is just unlucky! He seems to have timing belt failures more often than flat tires! Was if it was because the belt had never been replaced?

Now, we had to make a "forced change" twice because it was so difficult to get the adhesive to stick properly .

Quote:

Well, anyway, I've heard from several people here about problems with the crankshaft seal (or crankshaft). I'm going to try, as Olli suggested, to include a clause in the contract stating that the engine is "leakage-free."

Definitely a good idea.

Quote:

Furthermore, I have vowed to continue maintaining my own 80,000 km timing belt replacement interval. That helped me a lot with my golf game, and I think it will work well with the Audi too!

Absolutely! / Definitely! / In any case!

Hannes wrote:

It's not necessarily a bad thing if the pump is located at the rear of the engine; Audi did this with their first 5-cylinder diesel for space reasons (there was more room in the back because they also had to mount the radiator on the side), and they continued to do so. You could just as easily argue that it's bad that the pump on the 4-cylinder TDI (with a distributor injection pump) is driven directly by the timing belt, since this design dates back to 1976 with the first Golf 1.5D.

No, it doesn't necessarily have to be bad. I just laughed because I wasn't very familiar with the 5-cylinder TDI engine and now I've learned that it probably looks like the "old" swirl chamber engine.
However, I have concerns about the (expansion/elongation) tolerances that occur in such a drive system.
I actually think the timing belt (especially in PD engines) is absolute junk!!!! Unfortunately, there's nothing else available. I didn't want to buy a DI OPEL with a chain, and going for a DC or BMW is too expensive .

Bertil wrote:

No, it doesn't necessarily have to be bad. I just laughed because I wasn't very familiar with the 5-cylinder TDI engine and now I've learned that it probably looks like the "old" swirl chamber engine. Actually, I think the timing belt (especially in PD engines) is absolute junk!!!! Unfortunately, there's nothing else available. I didn't want to buy a DI OPEL with a chain, and my wallet isn't wide enough for a DC or BMW .

Audi wouldn't develop a completely new engine if it was easier to modify an existing one (the 6-cylinder diesel that was used in the LT and Volvo 240, 740, 940 models also had the fuel injection pump on the other side).

As far as I know, the next generation of PD-TDIs will have a timing chain. However, I don't understand why people are getting so worked up about the timing belt drive specifically in VW-Audi vehicles, when CR-diesel engines from Alfa-Lancia-Fiat, Renault, Peugeot-Citroen, Ford, etc., also use timing belts, yet no one seems to mind about that.

Best regards,

Hannes.

Hi,

@Hannes:
Well, the proportion of diesel vehicles produced by the Volkswagen Group (VAG) likely already exceeds the total volume of vehicles produced by the other brands you mentioned.
VW, Audi, Skoda, and Seat sell huge quantities of TDI vehicles.
A larger number of owners are affected in absolute terms compared to the other individual brands.
Furthermore, VAG is a pioneer and benchmark in the diesel sector, especially when it comes to direct injection (without wanting to imply any comparison with Mercedes).
People are paying closer attention and being more critical.

Furthermore, I believe that the timing belt, at the latest since the introduction of the PD engine, is reaching its limits. It experiences enormous stress.
And if VAG is already using timing belts, then why the heck don't they just build free-running engines? Sure, you might get stranded, but it would be less dramatic.

@Markus H.:

Okay, it's clear that TDIs are being scrutinized more closely, but I see a bigger problem: some people believe they can skip the (certainly not cheap) timing belt replacement, and that's when things usually go wrong.

You definitely can't build a free-revving engine for a diesel; the compression ratio is simply too high. In fact, I don't know of any diesel engines that are designed to be free-revving. Back in the day, those were mostly VW and Audi gasoline engines, specifically the 1.6L and 1.8L versions that were tuned for regular gasoline. Furthermore, the special piston design makes it even more difficult to achieve a free-revving characteristic.

I've already had two TDIs with broken timing belts, and both were repairable without major effort. In the case of the 5-cylinder engine, the camshaft broke in the middle, and I had to replace two valves; after that, the engine ran normally again without any oil consumption. And in the 4-cylinder engine, I only had to replace two valves, and it worked perfectly fine afterwards as well.
Furthermore, the fact that a chain isn't always the solution is evident in the case of the VM engine (found in various Chrysler Voyagers, Jeep Cherokees, Ford Scorpios, Alfa 155s, and 164s). In these vehicles, the timing chains frequently break.

Best regards,

Hannes.

I've owned an Audi 100 C4 TDI (AAT) since January of this year.
and the performance was increased to 145 horsepower through modifications to the original engine control unit (ECU).
raised. Due to the additional ceramic coating of the transmission and the...
The car runs much smoother and you can really feel the extra power.
after approximately 1000 km (many consider such measures to be voodoo, but...)
I tried it.
During the modification of the engine control units (ECUs), these were operated under normal driving conditions.
designed for more torque.
I've driven 25,000 km since then and I'm absolutely thrilled with it.
The power is insane.
A Mercedes-Benz E-Class 2.7 CDI has no chance.
(already tested on the highway).
The fuel consumption settles around 6.5 to 7 liters.
The problem with most of the '100' models is the transmission, specifically the 5-speed version.
It was also used in the 1980s and is not strong enough for the car. Many people experience noise from the transmission.
The 6-speed transmission is better and comes standard on the A6 with a power output of 103 kW.
I can only recommend the 100 and I will buy this model again as a station wagon in 2 years, because it is cheaper than an A4 with comparable mileage.

@Tommy:

The E270 CDI is far superior in terms of performance; it has at least 170 horsepower and a torque of 400 Nm, so you have no chance against it with any 5-series TDI, whether tuned or not. I've already driven that Mercedes, and compared to it, my AEL feels like a slow duck... However, the Audi also uses a liter less fuel than the Mercedes, and I still can't get used to Daimler's rear-wheel drive.

Best regards,

Hannes.

Hi,

@Tommy:

Hmmm. That 5-speed transmission must really be a weak point.
Mine also 'rushes' and 'grinds' too, but only after the transmission oil has warmed up.
But I'm getting a new one for free!
I whined, nagged, begged, pleaded, threatened – I did everything until the dealer finally agreed.
Although he believed that this noise was common in many Audis and would not affect their longevity.
Since I was concerned about preserving my sanity, I put in some effort to convince them – successfully.

Do you seriously think that the 2.5 TDI transmission is the same one that was used in the Audi 80 TDI?
That's almost a 100 Nm difference!