Old tdi 200hp++ vibration help

Hello,
I need help identifying the problem on my car.
Symptoms:
The vibration is RPM dependent. It all started half a year ago slowly progressing
What I am experiencing:
Starts at 1,6k rpm to 2,2k. It vibrates while in gear as well as in neutral while reving. Driving in higher gear (4th-5th) makes more vibration like a judder. It happens cruising on light throttle. If you jam gas pedal harder vibrations gone. Sometimes on very low rpms engine starts to missfire mostly when it is cold. Engaging clutch has no effect. In neutral slowly increasing rpm vibration stays at 2,2k rpm and the engine is shaky. As the engine overcomes that rpm range it is smooth.

Parts already changed/swaped:
Camshaft
Remanufactured engine head
Injection pump
Injectors tested in the shop and nozzles (0,280) recalibrated
2×gearboxes
Inner cv joints
Engine and trans mounts/also checked using polyrethane mounts
Different wheels/tires
New n75 solenoid
Few maf sensors
Single mass flywheel

What makes noticable change in terms of vibration:
While reving in neutral the engine is almost smooth as I disconnect vacuum line to actuator of turbo.
While driving vibrations almost gone if I disconnect vehicle speed sensor from gearbox

Some say stretched or damaged timing belt can cause such symptoms but I dont know

What are your thoughts?

Have a nice weekend!

Did you check your inner axel CV joint?

New ones both side no change

New or remand?

New skf

Just to clear something up the car only shakes under load. Nothing at all in neutral coasting at idle?

Coasting in neutral no vibration

I know this sounds kinda noob like but this has happend to me quite a few times.

Check the lug nuts /wheel studs.
My escape, my Jetta, and my van all had an issue like this. The Jetta was because I used the oem studs on my OZ wheels that need strait cut taper studs. The escape was due to lots of rust and crud stuck to the wheels mating surface. The van was because 2 lug nuts got stripped out by walmart. And snapped off.
All the same issue like yours. Check them all . Worth a shot!

What engine trans and gen is your car?

Not enough timing advance or bent rod(s).

Hmmm I think Markus is on a better path than me. Look into the timing and compression check your cylinders.

My vote is either axles or cv joints

Markus L said:

Not enough timing advance or bent rod(s).

Click to expand...

Timing is advanced at 65-67
Half a year ago I already had engine rebuilt because of bad noises coming from air filter. Turned out I had valves not closing enough and some small cracks in the head as well as 3 rods bent. The engine head was fully restored. Mechanic told that probably some water got through sport air filter which was possible due to uncovered area (now I use customised oem filter box).
You know what after rebuilt was made the driving was smooth with no vibration umfortunatelly just for a hundred kilometers. After one trip it came again.

On an old GTI I had. I would get brand new axels that would still cause a shake due to the inner CV having play.

Probably inner cv joints not seated properly...or just crap ones...

SmalkeMK3 said:

Timing is advanced at 65-67

Click to expand...

I have no idea what that means. Check a measuring block 004 while slowly increasing revs (standstill, neutral) to the vibration point and over that. Timing advance should increase with rpm.

Markus L said:

I have no idea what that means. Check a measuring block 004 while slowly increasing revs (standstill, neutral) to the vibration point and over that. Timing advance should increase with rpm.

Click to expand...

I just got my laptop back was able to make some logs and check live data. Check the video on youtube.
https://youtu.be/ax2zRAeQEoo
Also I have made output test for timing. The results dont look right to me
LATE ignition timing 3,7 - 4,0 BTDC Duty cycle 51 - 53%
EARLY ignition timing 7,7 - 7,9 BTDC Duty cycle 62 - 64%

Download a spectrum analyzer app for your smartphone and record the frequencies that the vibration peaks and simultaneously the engine RPM. Combustion or valvetrain-related NVH will occur at 0.5 engine order (half other frequency of the engine). Bent rods will show up in the first and second orders. Driveline-related NVH will not be proportional to RPM but rather gearing and vehicle speed.

Edit: I like to use Spectroid (for Android).

TDIMeister said:

Download a spectrum analyzer app for your smartphone and record the frequencies that the vibration peaks and simultaneously the engine RPM. Combustion or valvetrain-related NVH will occur at 0.5 engine order (half other frequency of the engine). Bent rods will show up in the first and second orders. Driveline-related NVH will not be proportional to RPM but rather gearing and vehicle speed.

Edit: I like to use Spectroid (for Android).

Click to expand...

I will try this app tomorrow. So I just put the phone on the dash panel?

Yes. A metal part of the body or chassis would be even better to remove damping and other effects of other materials. But if impractical then yes, on the dashboard will be fine.

BTW, I've used polyurethane mounts in a TDI before and didn't like them - unacceptable vibrations. Stick to OEM, or if you must, look for Delrin with the lowest durometer. I'm almost sure this is the source of your problem. You didn't mention what kind of car you have other than "old tdi". On the Mk3s and earlier there's a front upper and front lower mount at the radiator. When the engine is not under load, it rests on the upper mount, which looks like a cylinder the size of a drink can with a hole in the centre. When under load, the engine twists around the crank axis and lifts off the upper mount and loads the lower one, which looks like a hockey puck also with a hole in the centre). I suspect that you replaced the front upper mount with a polyurethane one and that's my prediction that is the source of your problem.

Edit: https://blackforestindustries.com/c...products/bfi-stage-5-complete-motor-mount-kit

I'm interested to what car, engine it is?

TDIMeister said:

BTW, I've used polyurethane mounts in a TDI before and didn't like them - unacceptable vibrations. Stick to OEM, or if you must, look for Delrin with the lowest durometer. I'm almost sure this is the source of your problem. You didn't mention what kind of car you have other than "old tdi". On the Mk3s and earlier there's a front upper and front lower mount at the radiator. When the engine is not under load, it rests on the upper mount, which looks like a cylinder the size of a drink can with a hole in the centre. When under load, the engine twists around the crank axis and lifts off the upper mount and loads the lower one, which looks like a hockey puck also with a hole in the centre). I suspect that you replaced the front upper mount with a polyurethane one and that's my prediction that is the source of your problem.

Edit: https://blackforestindustries.com/c...products/bfi-stage-5-complete-motor-mount-kit

Click to expand...

I am running oem engine mounts now. I have tried custom made polyrethane (80 shore) engine mounts. That didnt eliminate my problem just increased overall vibration. I mean just extra higher frequence vibration.

WarmStart said:

I'm interested to what car, engine it is?

Click to expand...

Vw golf mk3 tdi originally 110hp with an AFN engine

Well, then back to using a spectrum analyzer to narrow the source of the vibrations.

With those older engines is quite problematic crankshaft and pulley key. It may cause your problem...

I have ASV engine, I have bad nozzles, same symptoms.
When I let my engine run in idle some time (5-10 min) and then rev it, there are blue smoke form exhaused.

Maybe the balancer spun