Harmonic damper

[Gator79]

Have and aaz with a gasser flywheel and no harmonic damper and I getting some bad vibration in a certain rpm range could the lighter flywheel and no harmonic damper cause this.
Will getting a balancer help with the vibration?

[rabbit_tdi]

A quote from a VW article describing the development of the 1.6 TD and its 5 cyl. cousin:
"4- and 5-cylinder turbocharged Diesel engines are provided with a torsional vibration damper.  The main goal was to dampen the critical 6th order at 4800 rpm.  All other orders were less than +/- O.16 degrees crankangle.  The problem was solved by design modifications and the proper damper material selection."

Notice that this is torsional vibration.  If torsional vibration is occurring, I expect it would not be felt in the x-y-z directions --- one would just notice that eventually the crank would crack from excessive torsional stress.

My guess is that you have a different problem.  I have two 1.6 turbo-diesels with much lightened flywheels, and no trouble; one with a damper, and one without (I do not drive it much).  They accelerate a little more quickly --- and during a cold start on a cold day the engines are likely to not coast through a misfire at idle (which is not a problem, just run it at a fast idle until it warms slightly.

Is it possible that you have something out of balance, so that when it rotates there is a large rotating force in a plane perpendicular to the crankshaft?  Did the person that built the light flywheel balance it when they were done?

[theman53]

Don't worry about it coming apart these vw cranks are all forged and would take a ton before it would do that. The harmonic balancer could help, but on the N/A 1.6 they didn't even put one on that engine. I would guess the ligher flywheel is letting you feel more of the combustion process. How light is it? Also it could be out of balance and that is just like a tire going out of balance.

Also, being aaz they have the crank nose issue. I would search that and make sure that you are not shearing the keyway off the engine. It will cause the pulley to wobble which makes it go out of balance. If it is getting bad you can see the pulley wobble at idle.

[Gator79]

Not the crank it has been upgraded to the d sprocket. And the flywheel is just a stock after market 210 gasser.
Not much lighter then the diesel if I'm not mistaken. I only started to notice this when I went from the 190 diesel clutch to the 210 gasser. I have done the gov soni am revving it a bit higher, but the vibration it only between like 2500 to 3500 then stops.

[theman53]

Is this in Nuetral or running or both?

[theman53]

Also, depending on the gasser flywheel it could have a weird timing mark on it. If it is lighter than 9lbs it is the lightness that is causing most of it. You will feel the violence of the combustion process as the flywheel will not absorb it. My flywheel after machining weighed 9lbs and I could feel it a bit more than when it was 12. Under 9 and I bet it would be borderline unbearable with less than brand new soft engine mounts.

[Gator79]

The bad vibration where it shakes the dash and every thing inside is on pull between 2800 and 3800rpm then sto and is fine till the rest of the rpm range.

[8v-of-fury]

Are your motor mounts shot? Does it only happen with hard acceleration? or anytime in those RPMs?

[Gator79]

Front and back are new sides are old but still together.

And anytime not just hard exeleration.

[8v-of-fury]

Anytime, weird. Very weird.

[burn_your_money]

Not the crank it has been upgraded to the d sprocket.

This does not guarantee anything. TDIs that came stock with the D sprocket "commonly" experience this issue. It's worth checking the timing. Do you have a clutched alternator pulley? Do you have air in the lines under hard acceleration or high revving?

[theman53]

What car? Mk2? If you used poly urathane that will make it rougher. Even brand new mounts will break in a bit.

What 'aftermarket' fw do you have? Seems that the aftermarket gas fw are usually even lighter than the gas fw stock, so you could have a 6lb fw. Also, someone could have let one go that wasn't balanced properly.

Most evident though for me is when you said it was on a pull, not in nuetral. I would check your cv and tires to make sure they didn't lose a wheel weight or the balls in the cv didn't get messed up when you had the trans out.

[R.O.R-2.0]

What car? Mk2? If you used poly urathane that will make it rougher. Even brand new mounts will break in a bit.

What 'aftermarket' fw do you have? Seems that the aftermarket gas fw are usually even lighter than the gas fw stock, so you could have a 6lb fw. Also, someone could have let one go that wasn't balanced properly.

Most evident though for me is when you said it was on a pull, not in nuetral. I would check your cv and tires to make sure they didn't lose a wheel weight or the balls in the cv didn't get messed up when you had the trans out.

12-13# is stock..

19# is stock for diesels

6# would be WAY lightened..

[theman53]

my aaz flywheel weighed 12.8lbs stock. IIRC around 9lbs and under it is getting really bad.

[rabbit_tdi]

I have a 1.6 TD engine on which I installed a lightened flywheel, 210mm disk, and a high-load pressure plate.  I did not weigh the flywheel itself, but I did weigh the assembly.  The assembly is: flywheel, pressure plate, clutch disk, and release disk.  The reason I weighed the whole assembly is because every part was different than stock.  The assembly weighs 18 lb.  The engine runs fine.

When you adjusted the engine mount under the radiator, did you locate it so that it supports no weight?