TDI Issues? Troubleshooting & Solutions.

Hi, we're having a discussion about this in another forum, but nobody really knows for sure. At what RPM does a TDI engine's turbo stop boosting? For example, the 96 kW PD engine and the new 2.0 TDI? It's claimed that diesel engines don't have a rev limiter, but simply 'reach the end' of their power.

Best regards,

Hello, we're having a discussion about this in another forum, but nobody really knows for sure. At what RPM does a TDI engine's turbo stop boosting? For example, the 96 kW PD engine and the new 2.0 TDI? It's claimed that a diesel engine doesn't have a rev limiter, but simply 'ends' at a certain point?

Regards

Hello (also, hello to WOA visitors?),

When idling, a TDI engine will be limited to approximately 4600-4900 RPM during the gas bursts typically used in emissions testing. In normal driving conditions, the fuel injection amount in unmodified TDIs is automatically reduced around 4000 RPM due to the engine design, as the efficiency becomes too low.

Hello (also, hello to WOA visitors?),


Sure .
'I mean, is there a rev limiter like the one you find in gasoline engines?'

Hello,

In TDI engines, as well as in newer gasoline engines, the engine speed is regulated by the engine control unit (ECU).
I'm not aware of any older-style speed limiters like the ones found in the Golf I. Perhaps I haven't understood your question correctly! Is the other thread about the technical aspects, or about questions like 'My RS4 is limited to 250 km/h, does that also happen with TDI models?'

It's more about whether the engine is limited at any specific RPM during acceleration, for example, to prevent engine damage, rather than directly about the top speed.

Best regards,

My V6 engine stops accelerating just before reaching the redline.

As mentioned before, the TDi engines are electronically limited to a speed above 4000 RPM. Similarly, all modern gasoline-powered cars are also electronically limited via the engine control unit.

At speeds between 5000 and 5200 RPM, the TDI engine will be aggressively limited.

A diesel engine has a tendency towards self-destruction; it *must* be regulated, otherwise it would simply spin so fast at full throttle that it would destroy itself.

Previously, it was controlled by a mechanical regulator, but with TDI engines, it's controlled electronically.

I don't know how the engine management system works during driving, but it's quite possible that the engine will start to slow down in its highest gear even at 4000 RPM, because, as mentioned above, the efficiency becomes too low.

CU Gremlin.

I've run mine up to around 4500 RPM before, and it doesn't seem to be limited in any way, and there's still plenty of power available. Of course, you can't expect miracles at that point, but I've never pushed it so high that it actually reaches its maximum RPM (if it even has one).

Best regards,

It's possible that it won't regulate properly because, based on the translation of the current gear you're in, you're not even close to the RPM range where it would regulate.

Furthermore, it's not just diesel engines that self-destruct at high RPMs; gasoline engines do too.

Hello,

@wacken
I didn't write that it's the end at 4000 RPM! The fuel injection amount is reduced as the engine speed increases above 4000 RPM.
In tuned TDI engines, it's common for the full fuel injection amount to be maintained even at engine speeds well below 4000 RPM.
which then results in a slightly higher maximum speed.
In the lower gears, it's easily possible to rev a TDI engine up to its rev limiter. However, in the 5th or 6th gear, even with full throttle, a TDI engine won't reach the rev limiter due to the aforementioned reasons. The final rev limiter seems to vary depending on the specific engine code; my AKN engine cuts out somewhere between 4700 and 4900 RPM.

@x world one

Someone was probably faster!

My understanding is that the rated speed is always indicated there.

yes, where?

Meiner regelt bei 5150U/min ab. Chip-tuned AFN.

But the charging rate can be easily determined.

Just step on the gas!

Regards,

Manuel.

I'd rather leave that kind of ordeal to the TÜV.