AFN, cold turbo whistles

Hello everyone!

On my Passat 3B, engine code: AFN, manufactured in 1998 with 198,000 km on the odometer, I've noticed that the turbocharger whistles noticeably louder at around 1500 RPM when the engine is cold. However, this phenomenon disappears relatively quickly; after about 1 to 2 km of driving, the turbocharger returns to its normal sound level. It becomes particularly noticeable when the outside temperature is below 5° Celsius. The last oil change was performed approximately 4,000 km ago.

I bought the car with 130,000 km on the odometer, and there have been no engine repairs since then. The engine starts normally, and the performance is as expected. Oil changes have always been performed on time. Used oil: Castrol Magnatec 10W-40.
For about 8 months now, I've been driving around 120 km per day on weekdays, with 30% of that distance being within city limits and 70% being on the highway.
A diagnosis using VCDS revealed no abnormalities.

It should also be noted that after a prolonged period of idling (5 minutes) while the engine is warm, the vehicle emits a blue cloud with an oily smell when the accelerator is pressed.
Equally noticeable is the strong smell of oil coming from the exhaust after driving uphill for extended periods.

The oil consumption is approximately 1.5 to 2 liters for every 15,000 kilometers.

I will check the loader wave game at the next opportunity.

'Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein wunderschöner Tag, um spazieren zu gehen oder ein Picknick im Park zu machen. Viele Menschen genießen das gute Wetter und verbringen Zeit im Freien.'

'In my previous car, a Golf 3 with an AAZ engine, this whistling sound started appearing after 250,000 km - and only when the engine was cold. There was a slight amount of play in the turbocharger shaft, but also a slightly increased oil consumption.' After 10,000 km, the turbine inside the turbocharger broke down and came apart.


In a way, there are parallels to be found.
Do you perhaps have any experience with this phenomenon?

Best regards from Austria.

Manuel.

Hi,
Are you sure it's the supercharger that's making the noise, and not the timing belt or the serpentine belt?
I think the oil consumption is normal for now. The blue smoke when accelerating after a period of idling could also be caused by worn valve stem seals, which is especially common in gasoline engines. Another possibility is the valve on the crankcase ventilation system.
Are you sure it's oil smoke and not diesel blue smoke?
hg
Herbert.

Hello Herbert!

Yes, I'm sure the loader is making a whistling sound. It's like the loader shaft doesn't receive proper lubrication until one or two minutes after the engine is cold, and before that, the shaft whistles due to increased wear... If that were the case, it would likely destroy the turbo very quickly.
Perhaps it's just the poor lubrication... I have no idea.

I've done a little research online, and it seems like several other people are already aware of this. Mostly in older vehicles with high mileage.

The smoke is clearly coming from burnt engine oil.

Regards,

Manuel.

Hi!

I myself owned a T2 with the 1.6-liter TD engine for many years.
It also made a really loud whistling sound after the initial start, when it was building up pressure for the first time, which was almost embarrassing. It lasted for about half a minute, then it was gone.

I didn't find anything that was broken, and that lasted for about 15 years without anything happening.
I then sold the car, and it's still being driven around the neighboring town.

Later on, I attended a workshop training session about turbochargers.
"In response to my question about that, they said..."
That might be a pneumatic whistle, meaning the turbocharger housing is cracked, and the crack seals itself when it gets hot.

Hi, hello,
Oil smoke is definitely an indication of a defect. I've already mentioned the cheaper options.
Just to be safe, check the turbocharger, especially the intake side, for any issues (e.g., play, oil leaks). I would recommend checking the exhaust side after a few minutes of idling. If it's smoking, it's likely happening with a cold engine.
Without proper lubrication, a metal-on-metal sliding bearing would not make a whistling sound for hundreds of kilometers; instead, it would quickly seize up. The whistling sound is either caused by something else, or it's normal.
hg
Herbert.

My AFN engine in my 35i also whistled even when cold, until I sold it at 465,000 km, and I think it's still whistling now.

It also produced blue smoke when cold, but there was no measurable oil consumption over 10,000 km.

Hello!

Upon closer observation, I've now noticed that the oil consumption increases significantly towards the end of the service interval.

Similarly, the driving style has a significant impact.

What kind of engine is it? If it's the V6 engine, the filter in the crankcase ventilation system might be the cause of the smoke.

AFN = 4-cylinder engine. VEP TDI

hg
Herbert.

I've added it above in the text; apparently, Niko hadn't read the thread title.

My AFN in the 35i also whistled when cold, up to 465,000 km when I sold it, and I think it's still whistling now.

It also showed blue smoke when cold, but had no measurable oil consumption over 10,000 km .

I had the AFN engine in my Volkswagen Golf 3.
313,000 km. The turbocharger is cold and makes a loud whistling noise, more so when cold than when warm. However, my Audi AEL with a K14 turbocharger exhibits the same behavior. He barks more than he bites.
What can you hear at second 42 ?

Oil consumption with the AFN engine back then: less than 1 liter per 15,000 km.
Oil consumption AEL: 0.25L per 15,000 km (total mileage: 332,450 km).http://www.youtube.com/watch?v=T77FzPZw7yI&feature=related{MARKER}