Wastegate Question: Troubleshooting & Explained

Hello,

I have a question.

Does the 5-cylinder ACV engine in the T4 have a wastegate turbocharger or a variable geometry turbocharger (VTG)?

The background is as follows:
I drove my dad's T4 again, and you hear this howling sound when you take your foot off the gas. I then searched online and found a topic where someone was talking about their ACV and a wastegate. If the ACV really has a wastegate, then my 1Z should also be making those noises, right?

Hi,
The '96 ACV, which I occasionally tinker with, has a...
Wastegate turbocharger. I wonder if VW will use this for the newer models as well.
'whether it lasted or if it failed (similar to what happened with the 90hp versions).'
at some point, it was switched to VTG

Best regards, Rudi.

@ Rudi

The 90 horsepower models received a different engine code because they were equipped with a VTG turbocharger.

AGR - WG
ALH - VTG

@ Doc

A colleague of mine who drives an AHU vehicle has a constant, very noticeable whining noise coming from the turbocharger. I haven't heard anything this loud from a turbocharger before, but he's already driven 170,000 kilometers with it.

So, I wouldn't worry too much. They are just louder.
Furthermore, the T4 has a completely different level of sound insulation (obviously, because it's a different car), and this could naturally lead to acoustic differences.

m;

Hi Martin,
Understood (at least regarding the 90 horsepower).
At VW, they only do some things a little bit differently .
An example of a 018x STG (throttle body) from a 1.9L engine is an MSA15.7.
(C166 CPU, 2xPLCC32 EPROM). In the T4, 018x is an EDC15 with a C167.
and 1xPLCC44 Flash.

Best regards, Rudi.

My topic title was also a bit poorly chosen, almost the same as haehnlein's, well...

My Passat still has the problem with the delayed turbocharger boost. And the T4 pulls nicely from low RPM, or you can really feel the difference compared to my car when the turbo kicks in. I was just a bit unsure whether those noises are normally heard with a wastegate turbocharger.

Hi Doc,
'Could you please log the boost pressure and compare it to mine?'
1Z (okay, not quite original ) at.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Possibly, also log the injection amounts and see who is responsible for that amount.
limited (torque or Russian).

Best regards, Rudi.

@DocSnydor

'Wastegate turbochargers can also whine like dogs under a full moon. *g* It's less common, but when it happens, it's really noticeable. A guy from my town drives a Vento TDI with the 1Z engine, and his turbocharger also makes a nice whining sound. It's driving all the VTGs crazy. But, his engine is just different anyway. It knocks in a very distinct way (so it doesn't sound like a 1Z engine at all), and it also sounds a bit strange inside the car (well, it's probably due to the sound insulation), and it just makes this crazy whining noise.'

Best regards, WarLord.

Hi Doc,
'Could you please create a log of the boost pressure and compare it to mine?'
1Z (okay, not quite original ) at.
/viewtopic.php?t=5705

Possibly, also log the injection amounts and see who is responsible for that amount.
limited (torque or Russian).

Greetings, Rudi.

Thanks, Rudi, for the tips. I'll try them out sometime... Right now, I have another project: My radiator gave up the ghost yesterday...

I just logged the fuel injection amount.

The value for torque at a specific fuel injection amount was always lower than the value for smoke reduction at the same fuel injection amount. Is that okay? The torque values are fixed numbers, right? They aren't calculated from anything?

The amount of fuel injected was sometimes larger than both of the specified values.

Regarding the topic of delayed boost pressure build-up, again.
'It's likely that my WG gate isn't closing properly, and the pressure bleeds off at low RPM because the exhaust flow isn't strong enough yet to compensate.'

'And if I'm driving faster on the highway and take my foot off the gas, I still have about 250-300 mbar of boost pressure at around 3000 RPM. Isn't that unusual? Shouldn't it be completely at 0?'
That's probably related to the fact that the wastegate isn't opening wide enough.

'Does anyone know if the WG (wastegate) needs to be adjusted manually? I couldn't seem to do it back then, but it moved when I blew air into it with a compressor. The error memory doesn't show anything either, probably just within the tolerance range. If I could just get better access to it, I would have removed the turbocharger a long time ago...'

Here's another frustrating experience: Our new car has a VTG turbocharger, and it only makes a very quiet whistling sound when it's cold. Why can't I ever find a turbocharger that makes a really loud, aggressive whistling sound?

Best regards, WarLord.

@warlord

Is a loud engine noise primarily necessary? Isn't it more important that the engine and, consequently, the motor function properly and operate within the promised performance range? Whether it makes a loud noise or not doesn't really matter.

Furthermore, this is about a wastegate, not a VTG turbocharger! }

@warlord

Is a loud engine noise primarily necessary? Isn't it more important that the engine and, consequently, the motor function properly and operate within the promised performance range? Whether it makes a loud noise or not doesn't really matter.

Furthermore, this is about a wastegate and not a VTG turbocharger!

*lol* Exactly, if I want to hear howling, I'll buy a wolf. }

But it's true, the engine can make some great sounds. Better than any aftermarket exhaust system.

This weekend, I'll be working under the car anyway, changing the transmission and engine oil. I might also take another look at the wastegate adjustment; it might be a bit stiff.

Short conclusion, for those who are interested

Transmission fluid change:

The old oil was still present after 250,000 km and over 10 years. It was reddish and still looked quite clean (no visible metal shavings). The oil drain plugs were very difficult to remove (17mm Allen key -> a 2-meter long threaded rod was welded to the lug bolt). I now have Castrol Taf-X in it. The gear shifting is now very smooth, and it doesn't 'jerk' as much anymore. Unfortunately, the oil was quite expensive (7 euros / 0.5 liters -> you need almost 2 liters for the 'Frontkratzer' model).

Wastegate adjustment:

I've been messing around with some copper paste, but the adjustment on my 35i definitely can't be moved by hand. Can a 1Z / AHU driver confirm this?
It's almost impossible to remove the charger for testing because you can't see anything and can't access the rusty screws.

Intake manifold:

I replaced the gasket between the intake manifold and the cylinder head (it costs less than 4 euros at VW). After over 40,000 km of driving with a faulty EGR valve, the intake manifold was still perfectly clean, as if I had just cleaned it, why is that?

LMM - Diode:

'After driving for approximately 40,000 kilometers without a mass airflow sensor (MAF), but using the 'diode trick' instead, I finally bought a new MAF sensor from VW. The (turbo) boost now kicks in much more noticeably than with the diode (unfortunately, it's still too late). The top speed and acceleration from 2500 RPM remain the same.'

Kat:

I got a replacement catalytic converter and had it installed. I can definitely feel a noticeable increase in performance, and I'm hearing the turbocharger spools for the first time.

However, I haven't figured out the cause of my boost pressure problem. The only new thing I've discovered is that sometimes the full boost pressure comes on earlier (around 2300 RPM), and sometimes later (around 2500 RPM).

DocSnydor wrote:

A brief conclusion for those who are interested. I've been messing around with some copper paste, but the adjustment on my 35i definitely can't be moved by hand. Can a 1Z / AHU driver confirm this?

Yep, you can't move it manually. There's a very strong spring inside the canister. (My wastegate is working fine, which is probably the only properly functioning part on my 1Z engine.)

DocSnydor wrote:

A brief conclusion for those who are interested. "After driving for approximately 40,000 kilometers without a mass airflow sensor (MAF), but using the 'diode trick' instead, I finally bought a new MAF sensor from VW. The (turbo) boost now kicks in much more noticeably than with the diode (unfortunately, it's still too late). The top speed and acceleration from 2500 RPM remain the same."

Okay, I also drove with the Diode chip, and now I have a new MAF sensor installed. The turbo lag is MUCH more noticeable. Also, it's not smoking as much anymore. Not that I ever saw anything in the rearview mirror, but it was confirmed by my colleagues ("no more afterburner...?").

/Jan

Jan and Doc.

What has grown since you installed a new mass airflow sensor?

SHOOT or MISS (Miss = NO SHOOT)???

I'm sorry, but I can't translate that because it only contains question marks. Please provide some actual text for me to translate.

m, who fixed the hole with a 500 Ohm resistor at the pump .

@Martin

You can really feel the turbo kicking in much more noticeably with my Passat now. With the diode, it felt more consistent, almost like it wasn't a typical TDI.
Before using the turbo, it feels worse; afterwards, it feels about the same.

I couldn't see any black smoke in my rearview mirror, even with the diode.