Harmonic balancer from gasoline engine on TDI??? Please read!

Hello there!

I'm currently working on my Audi A4 (AFN) and replacing the flywheel from a G60 engine (1.8 liter). Sorry if this question seems silly, but could this cause any major damage or other issues?

I would be grateful for any help/information.
Arne.

Hi Arne,

wieso fährst Du denn eine andere Schwungscheibe? Ich nehme mal an, daß sie leichter und der Motor dadurch drehfreudiger ist. Sinn der Schwungscheibe ist ja ein ruhiger und gleichmäßiger Motorlauf. Da mit geringerer Schwungmasse die Vibrationen zunehmen, würde ich sagen, daß bestimmt auch irgendwo das Material darunter leidet. Was als erstes den Geist aufgibt, kann ich nicht sagen. II can imagine that the first thing to happen would be for the clutch springs to weaken, which would result in poorer clutch performance.

Regards,

Eike.

I'm using a different flywheel because the car I bought for its engine was involved in an accident and hit the asphalt, which damaged the flywheel. We had just installed that flywheel previously.
You are the one who started it.

Damn, what am I supposed to do now? The engine sounds a bit strange when it's idling. But as far as driving and acceleration are concerned, it seems completely normal to me.

Arne (open to all answers)

Hello!

So far, I've only seen mopeds that use a lighter flywheel to achieve better acceleration. As a result, the idle speed tends to be less stable.

'This also changes the resonance frequencies for torsional vibrations, i.e., the rotational speeds that are harmful to the crankshaft. Someone could (not me) calculate this precisely, but in a 4-cylinder diesel engine, these frequencies are usually not critical, and you say that you don't notice anything unusual during normal operation.'

Theoretically speaking, I would say leave the lighter disc in place.
Best regards, Ernst.

Thanks to Ernst as well. That makes me feel a little better.

But who says that the disc is lighter?


For any further comments, I would be very grateful!

Regards,
Arne.

Hi Arne,

What exactly was broken on that part? Was it a dual-mass flywheel? I believe most TDI engines have one, and I wouldn't just replace it with a "regular" flywheel without considering the significant role it plays in reducing vibrations.

Best regards,

Jan.

But who says that the disc is lighter?
The engine sounds a bit strange when the car is stationary.

Therefore, I was thinking about something lighter. But a diesel engine (literally 'nail animal'), in my opinion, always sounds somewhat strange when it's idling.
Best regards,
Ernst.

P.S. Theoretically, a little bit heavier is just as insignificant as a little bit lighter.

P.P.S If it's like what Jan says, then it's something completely different. The original disc was NOT rotationally symmetric (excluding the dent).

Ugh - the engine is a 1997 AFN from a Seat Toledo.
Does it already have a two-mass flywheel?

Okay, I'm really frustrated now. I don't want to break anything. The car is just finished, and my bank account is empty until the end of the year.

'When I'm standing still and not pressing the clutch, there's a noise coming from the transmission. But when I press the clutch and listen again, the engine sounds completely normal.'
Could this possibly be related to the flywheel?


Ugh.
Arne.

Thank you for your efforts.

Hi Arne,

What did the part in question look like? Does Ernst's description match?

Otherwise, I believe that the AFN likely has a central management system, but I'm not entirely sure.

You can try searching for the term; I believe it was discussed before in relation to rattling noises at low RPMs and loose rollers. You might find engine codes that way.

As far as I remember, there was a link to the manufacturer included, along with an image. I believe it was in the new forum, so it should be findable.

Best regards,

Jan.

Arne wrote:

When I'm standing still and not pressing the clutch, something makes a noise (it comes from the transmission). If I then press the clutch and listen again, the engine sounds completely normal. Could this possibly be related to the flywheel?

"That sounds like a clutch release bearing."

What kind of release bearing are you using? Is it the one from the AFN or the one from the G60? If you're using the TDI release bearing, it might not fit properly with the G60 clutch and could rattle when the clutch is engaged.

Quickly searched the web and already found something:

While the two counter-rotating balance shafts rotate at twice the engine speed to eliminate secondary inertial forces and thus vibrations and noise, a dual-mass flywheel further decouples the body from torsional vibrations of the powertrain.

If anyone finds a picture, they can post the link here.
From a structural integrity standpoint, I wouldn't be too worried about the engine itself. What the dual-mass flywheel (ZMS) does is primarily aimed at improving comfort.
Just to reassure you: Motorcycles (especially choppers) often experience extreme vibrations at medium to high engine speeds. And even though the crankshaft bends significantly under those conditions, there are no issues with its strength.
So, if your TDI isn't even vibrating more than usual, you definitely don't need to panic and can continue driving until you have enough money to fix it.
Best regards, Ernst.

Hello everyone,

First of all, thank you again for your participation.
Ich habe vom Kollegen erfahren, dass der AFN das normale Schwungrad hat. Okay, no ZMS.

@Jan6K
I took a look at the flywheel. But it doesn't seem to have two separate masses. It's a normal disc with a thicker rim around the edge, and that rim is interrupted twice by sections about 3 cm long.

@Bertil
I can't tell you which type of rear axle bearing I have installed. I had the conversion done with a colleague from VW, and I only provided the part numbers or did smaller jobs myself.

@everyone
The engine roars quite loudly in the first two gears when I accelerate fully. But I think that's simply due to the power and the fact that it's struggling for grip on the asphalt. Because in the third, fourth, and fifth gears, it's much quieter.

I just returned from a test drive on the highway. The AFN engine in my Corrado is now reaching 210 km/h (according to the speedometer). I think that's okay. Driving at 170 km/h feels very comfortable. I have the gearbox from the 90 hp TDI model installed, which is 8 km/h longer than the one for the 110 hp version.
'So, when I drive at around 170 km/h, I don't notice anything from the flywheel. Everything is great. As I said, it only makes a roaring noise when accelerating fully in first and second gear. There's also quite a bit of vibration then.'

So, can I leave the flywheel from the G60 installed?
Don't tell me the crankshaft will fail after only 5000 kilometers!

Good night.
Arne.

Hello Arne,

Arne wrote:

The engine roars quite loudly in the first two gears when I accelerate fully. But I think that's simply due to the power and the fact that it's gripping the asphalt. Because the third, fourth, and fifth gears are very quiet.

What you're writing here is another mistake. When you accelerate, the engine tilts backward, and it seems to be hitting something. It could also be that one of the engine mounts is broken, causing the engine to tilt too far. In any case, I would say this has nothing to do with the flywheel.
By the way, I've been dealing with this kind of roaring noise for about two years now (only when accelerating fully in first or second gear), and no one has been able to find the source of the problem.

Yes, you are right. The engine isn't running as smoothly for me anymore. When the car is stationary with the handbrake on, the engine seems to wander a bit. But I can still get it sorted out.

What is *much* more important is this damn flywheel .

Arne.

Can anyone really offer me any advice on this?

Where can I find information about the weight?
And who can give me more detailed information about whether this will damage anything?
Or perhaps an email address from someone at their office in Wolfsburg...

ohoh,

Arne.


Here are the images of the AFN and G60 flywheel respectively:

AFN: http://www.meckisfaq.de/antworten/motor/diesel/g/Image95.jpg
G60...