PD ATD: 5-Cent Tuning - Is It Worth It?

Hello everyone,
I'm new here as a writer, although I've been reading occasionally for a while.
Great forum, I've already learned quite a bit .

But speaking of the topic:
I've been driving a Golf 4 (see profile) for 40,000 km (1 year).
of which the last 10,000 km were driven with a 150-ohm resistor instead of the diesel temperature sensor.
(I'm also one of those people who get scammed on eBay, price: €17 + shipping).

I've already done some searching here, and it seems you're not thrilled with the solution.
but:

- significantly more torque at low RPMs.
80-120 in the 5th grade: approximately 350 meters without equipment, approximately 250 meters with equipment.
reproducible; I remove this part during inspections and then test it again.
Tested in both approximately 15°C and 30°C ambient temperatures.

- Fuel consumption decreases by approximately 0.5 liters (according to the fuel log).
it could be because I didn't use the feature very often.
I might drive more carefully now because I'm worried about the engine.

I haven't tried Vmax yet, I'm too afraid .
The MFA now shows significantly lower consumption, about 0.5L/100 too low .
'I haven't noticed any excessive black smoke yet. Is the injection amount excessively high?'

Regarding my questions:
What is your estimate of the chances that the engine will last another 40,000 miles?
'Increasing the fuel injection volume extends the injection duration, and the back pressure at the injector nozzle increases the diesel temperature. However, this is only a problem if the engine's power is being fully utilized, such as during strong acceleration or at maximum speed, correct?'
3. If the diesel temperature is high, the return flow to the tank mixes with cold diesel.
(I think I read this somewhere.)
Then he always does that with the resistance, right?
That should help to mitigate the problem of excessively hot diesel fuel in the return line, right?
4. Are the other modifications costing less than 1 euro more gentle on the engine?

Thanks in advance, Thomas.

P.S. I'm just a user, I have no means of making a diagnosis.

Hi Thomas,

Regarding point 1: As with all tuning modifications, it depends on the specific requirements. If you demand a lot of performance, the lifespan will suffer accordingly.
Regarding point 2: That is correct.
Regarding point 3: Yes and no. If a switchable cooling system is installed, it's possible that the constant temperature setting is just enough to deactivate the cooling. A mechanic showed me some pictures a while ago of a gas station where a Golf 4 TDI (with this type of temperature tuning) had melted its fuel tank, causing a massive spill. The cleanup operation by the fire department cost the Golf owner approximately 22,000 euros.
The problem is this: The temperature is constantly maintained at around 100°C by a resistor. At these temperatures, the fuel itself can cool the mixture by mixing it with "fresh" fuel from the tank. The control unit no longer detects higher temperatures and may not activate the auxiliary cooling system. This is particularly critical when the tank is nearly empty, as the cooling volume is then much smaller.
Regarding point 4: A clear no. This is always mentioned in the technical articles! However, moderate "tuning" can still extend the engine's lifespan.

My experience with AXR is quite clear:
With the current high temperatures, any increase due to cold weather is no longer noticeable.

If the switching point were below 100°C, would everything be fine?
From what temperatures does a tank melt?
How long do I have to drive a Volgas before the diesel gets *that* hot?
Isn't the exhaust system much hotter and also close to the fuel tank?

With my ATD, I can increase the performance.
I think you can notice it even with the current temperatures.
I'm going to drive my test route again this afternoon.
to prove that, and I'll get back to you.

durnesss wrote:

From what temperatures does a tank melt?

I can't say exactly what quality of plastic it is, but generally, 150°C is already quite a challenge for "normal" plastics. Of course, there are plastics that are much more heat-resistant, but those are also significantly more expensive.

Quote:

How long do I have to drive a Volgas before the diesel gets *that* hot?

It depends on the environmental conditions. However, when driving at full speed on the highway, you might be lucky because the airflow could actually cool the fuel tank. City driving is more likely to be a problem (especially when driving at full throttle at low speeds?).

Quote:

Isn't the exhaust system much hotter and also close to the fuel tank?

Yes, the exhaust system is warmer. However, normally the exhaust pipe is protected from the plastic with heat shields. The air between them also acts as insulation!

Quote:

With my ATD, I can increase the performance. I think you can notice it even with the current temperatures. I'm going to drive my test route again this afternoon. to prove that, and I will get back to you

.
Please perform the "Ulf test"; it's more accurate and has better reproducibility.

Okay, I'm ready. Please provide the German text you want me to translate.

hi,
Why not simply make the whole thing switchable with a switch? You could either connect the resistor in parallel or in series (depending on whether it's a PTC or NTC resistor) with the fuel temperature sensor, or bridge the resistor with a switch. This way, it should even be possible to switch it while driving.
'Does anyone happen to have a specification for the fuel temperature sensor? I'd like to try it on my Lupo 1.4 TDI/PD, but I don't want to start experimenting with different resistance values.'


Regards,

Björn.

....in VW vehicles, the fuel cooling system is not controlled by the engine control unit (ECU)! Instead, an underbody cooler is often used to cool the returning fuel.

The effect of this 'tuning measure' is likely to be noticeable only during acceleration. During prolonged periods of full throttle, the actual fuel temperature will stabilize at around 100°C, at which point no further correction will occur. This is because the tuning measure may be artificially forcing the engine control unit (ECU) to believe that the fuel temperature is constantly at 100°C.

The critical temperature for the tank starts at 90°C... It's a misconception that the temperatures inside the tank increase, especially when the tank is almost empty. The tank acts like a radiator, and with a small amount of fuel in the tank, the ratio of surface area to volume is higher. Therefore, the fuel inside the tank is cooled. However, when the tank is half full, the surface area hardly increases compared to the volume, which increases significantly. This is why it's much more critical to have a tank that's half full.

In general, if you're already concerned about the lifespan of your engine (perhaps because you're worried about the potential costs of repairs in case of damage?), you should probably consider spending a little more money to get the next more powerful engine!

Best, Ben.


P.S.: It shouldn't be forgotten that the exhaust temperature also increases, and there are very sensitive components that don't like that at all .

I'm going to look for a Golf with around 150 horsepower.
This whole charade is becoming increasingly suspicious to me .
It might work out well, but if it doesn't, it's going to be very, very expensive.

Thank you, Thomas, until here.

Hi Thomas,

durnesss wrote:

I will start looking for a Golf with 150 horsepower. This whole charade is becoming increasingly suspicious to me . It might work out well, but if it doesn't, it's going to be very, very expensive.

... good decision ...

Sorry.
I know I'm bringing up an old thread, but it's part of the process.

What are your thoughts on the 2.5L TDI engine with 150 horsepower, or even the one with 180 horsepower?
I am facing a decision: either...

A6 station wagon, 04/1999, 2.5 TDI 150 hp, 98,000 km.
with MFA, GRA, climate control, power steering, and lots of extras, for €19,500.
or
A6, 4-door, 12/2000, 2.5 TDI, 180 hp, 90,000 km.
with MFA (Multi-Function Display), climate control, power-adjustable headrests, and slightly less equipment for €19,000.

I'm leaning towards a station wagon, but the other one is newer and faster!
Or are 98,000 km a low mileage for a 6-cylinder engine?
'How much does it cost to replace the timing belt at 120,000 km?'
What is their fuel consumption per 100km?
Do they have any particular quirks?

Thank you for any information.

Hello,

I would base the purchase decision on whether it's limited to these two models, and if so, I would depend on the engine code of the 150 hp A6. If it's the AFB engine, there's a lot of information available about it; the same goes for the AKN engine.
As for me, I can only report positive experiences so far. The engine runs very smoothly, and it pulls really well from around 1500 RPM. The timing belt replacement is extremely expensive for both models, costing approximately 700-800 euros, depending on what else is done at the same time. My A4 is currently consuming 6.7 liters per 100 kilometers (approximately 6.7 liters per city driving).

Does anyone else have an opinion on these two engines?

Thank you.

I'm going to start a new thread.
That has nothing to do with the actual topic anymore.

I have another question about fuel cooling. Does the G3 1Z also have something like that? I haven't found anything like it yet. There's only the mechanical valve on the diesel filter. I'm a bit worried now, because I'm driving around with the gasoline fuel lines. It seemed like too much work to replace them as well.

Regards,
Jan.

Jan03 wrote:

I have another question about fuel cooling. Does a G3 1Z also have something like that? I haven't found anything like it yet. There's only the mechanical valve on the diesel filter. I'm a bit worried now, because I'm driving around with the fuel lines from the gasoline engine. It seemed like too much work to replace them as well. Regards, Jan

Here's the translation:

This is about common rail diesel engines.

Okay, I know, but since the VP44 apparently also has a fuel cooler in the return line (which I read somewhere recently), I thought I'd ask...

/Jan