Engine Performance Issues After 75k Miles?

Hello everyone.
'For some time now, I've been experiencing the following problem with my Volkswagen Vento.'
When I accelerate fully, it makes a louder sputtering noise than usual.
Also, it doesn't accelerate as quickly as it used to. I have no idea why.
Here's my setup:

1.4L engine, 90 horsepower, 120,000 km mileage, K&N air filter (since 30,000 km), EGR deactivated (since 10,000 km), MSD replacement exhaust pipe (since 5,000 km), sports exhaust system (since 5,000 km), new fuel injector (since 20,000 km), ECU chip tuning (from 90,000 to 115,000 km - now removed).

Who knows the answer???

Thank you in advance.

Hi.

Less power and more soot is actually the classic symptom of an EGR valve that isn't (completely) closing. That would be the cheapest option. I would therefore check it, even though the EGR should theoretically be dead.

If he's also experiencing new starting problems: Caution, is the crankshaft timing belt pulley loose?

If it's a more gradual process, I think worn nozzles should also be considered.

Or are you expecting the same performance as in winter?

Perhaps it's just a batch of "bad" fuel? Try switching gas stations as a test.

Hello!
First of all, thank you for the response.
Ich hab den Fehlerspeicher auslesen lassn. Nothing!
I filled up with the good Aral Super Diesel fuel, but it didn't make any difference.

The car doesn't have any starting problems. But I still suspect something else:
The turbo. Because the engine revs up normally, but the acceleration isn't the same anymore. Also, I have the feeling that the car is slowing down faster. (That's a clumsy way of putting it), meaning that when I take my foot off the gas, the speedometer needle drops towards zero more quickly. Hopefully, this helps with the diagnosis...

Thank you again.

P.S.: Could it also be the solenoid valve?

Hi.

Quote:

Could it also be the solenoid valve?

It's probably not the charger, because normally that wouldn't cause an increase in soot emissions.

The AGR is likely to close sooner rather than later, especially if the "termination" process hasn't been entirely successful, and now the AGR is experiencing a significant delay in its closure.

The stronger braking effect of the engine... hmm, older diesel trucks have what's called an exhaust brake, which activates some kind of valve in the exhaust system (I don't know exactly how it works).
If a malfunctioning EGR valve could cause something similar, it would also explain the stronger braking effect during acceleration. However, I'm naturally assuming that there isn't some kind of brake stuck (indicated by consistent rim temperature after at least 10 km of driving?).

Hi there,

"These are fairly typical mechanical causes, such as wheel bearings that aren't spinning freely or brakes that may be stuck. However, given the mileage, these possibilities shouldn't be ruled out either."
The type of tire can also slightly influence the rolling resistance...

Has there been any change in consumption?

Olli.

Hi!
No, the consumption has not changed.
Besides, I'm still using the same tires.
It must be something related to the engine.
I think so, at least.

Sure, here is the translation of the text from German to English:

'MFG' stands for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English. It is a common way to end a formal letter or email.

Hello,

'I'm also experiencing a perceived loss of power in my 1Z engine (Passat with 200,000 km). I think it's not accelerating properly, at least from the perspective of speed. The RPMs are increasing like they are with Ventoman. However, I don't have any black smoke, and the fuel consumption is normal. What's strange is that the top speed seems to be okay (210 km/h according to the speedometer going downhill, so around 190-195 km/h).'
We have a 1Z G3 at the company, and it performs completely differently (much better...) , even though everyone is constantly experimenting with it.
'Mine is also much louder and sounds quite rougher than other TDIs (exhaust and air filter are all original...).'

What could be the reason for that?

Sure, no problem. Just let me know what you need translated.
Dave.

DocSnydor wrote:

I also suspect that my 1Z engine has slightly reduced performance (Passat, 200,000 km). I also think it's not accelerating properly, at least in terms of speed; the RPMs are increasing just like with Ventoman. However, I don't have any black smoke, and the fuel consumption is normal. And what's strange is that the top speed is still okay (210 km/h according to the speedometer going downhill, so about 190-195 km/h). We have a 1Z G3 at the company, and it performs very differently (much better...) , even though everyone is constantly experimenting with it. "Mine is also much louder and sounds quite rougher than other TDIs (exhaust and air filter are all original...)." What could that be due to?

Hi.

Comparing a Passat to a Golf 3 is probably quite "subjective": heavier cars are practically always quieter and slower than lighter ones.
You can at least simulate the performance characteristics of both cars using the registration data in the calculation tool. I think that will resolve some of the apparent "contradictions."

Otherwise, at around 200,000 km, it might be worth replacing the injectors if they are still the original ones .

@ Ulf:

Hello,

I already know that the Golf is lighter (even though it's a variant). But even considering those few kilograms, the Golf feels completely different; the driving experience is very different. I also meant that my car makes more noise than other TDIs, not the other way around.
I've also had the thought about the injectors, but in other posts where it helped, the black smoke disappeared afterward. However, mine doesn't produce any black smoke at all, not even when accelerating hard.
I'm going to take it to Bosch and have them test it. Hopefully, it won't cost too much... Does anyone know how much that might be?

Dave.

ATU wanted to charge €75 for it, which included disassembly, testing, and reinstallation.

At the Bosch service center, they wanted 15 euros just for the testing, and extra for removing and installing it. So, you should expect to pay at least 60 euros if you have the workshop do everything. }

@ulf:

Hi again!
I've tried the following now.
1.) Cleaned and re-oiled the K&N air filter.
2.) Filled up with premium gasoline.
3.) Tighten the hose from the EGR valve and ensure it is airtight.

Here are some other things I could do:
1.) Replace the magnetic valve on the turbocharger. A friend has a spare one lying around.

What else could I do? How can you measure the boost pressure while driving? Without a boost gauge, for example, from VDO.
I have the feeling that not enough pressure is being built up. Somehow, there's a lack of that sudden burst of power around approximately 1900 RPM.

Sure, here is the translation of the text from German to English:

'MFG' stands for 'Mit freundlichen Grüßen,' which translates to 'Sincerely' or 'Best regards' in English. It is a common way to end a formal letter or email.

Hi.

...you either need a pressure gauge/LDA or a laptop with a 155xx VAG diagnostic tool.

"Digital measurement" has the disadvantage that a faulty sensor in the Electronic Direct Control (EDC) system may go unnoticed, whereas when comparing with a (functional) mechanical Linear Displacement Analyzer (LDA), any incorrect pressure reading will be immediately apparent, regardless of where the error lies.

'If there is a pressure loss on the high-pressure side of the turbocharger, these symptoms would occur (excessive diesel fuel consumption, insufficient air intake because the mass airflow sensor assumes everything is normal). In such cases, I always measure the boost pressure (manually). Measuring and testing the high-pressure side is becoming increasingly difficult in newer cars because there are fewer connection points. If you're still interested, I can provide more information.'

Hi!
How can I check the boost pressure while driving? What should it be (at full load, etc.)?
Is there a way to increase the charging current of the 1Z?

Thank you.

Hello. Buy or borrow a boost pressure gauge (e.g., from eBay). Find a connection point on the intake manifold or air inlet pipe (possibly using a T-connector). Connect the hose to the interior of the gauge and start the engine (ideally with someone else present). If you have approximately 0.9 bar (1.9 absolute) boost pressure, then the cause of your power loss is elsewhere. If you have less than 0.7 bar, you need to find the leak. To increase boost: either use a chip or adjust the linkage on the turbocharger control unit (if it goes into limp mode during acceleration, you've adjusted it too much). Have fun.

HI!
How should I twist the rod?
If the boost pressure is too low, could the turbo be broken? A new turbo can be quite expensive. Or where else could the problem lie?
I'm going to do a test run with the VW diagnostic tool next week. Hopefully, I'll know more then.