TDI 1Z: No Power? Troubleshooting Guide

Hello.

My Golf 3 TDI 1Z has had very little power across the entire RPM range for some time now.

The error reading shows a defective control unit.
Error code: 655 35.
00-00--


Now I bought a new one and installed it, but nothing has changed; I'm still experiencing the same error and still getting no power.

I have the usual things, and I've already checked the turbo!

Could it be related to the control unit at relay 109?

The car also starts to make a clicking noise when it's fully warmed up, starting at around 2300 RPM.

I've already replaced the connecting rod bearings because a VW master mechanic thought they were causing the knocking sound.

The Hydros are fine too.

I cannot translate this as it appears to be a string of question marks.

I am grateful for any advice.


Best regards, Christian.

I have the usual things, and I've already checked the turbo!

What were the usual things?
You've already put hundreds of euros into the car, and you're barely getting anywhere?

Sure, I'm ready. Ask your questions.

1. What is the mileage of the vehicle?
Does the clicking sound also occur when the drawer is being opened and closed?
3. Is there any smoke coming from the exhaust?
4. Were the valve timings checked?


Otherwise, too many possibilities come into consideration.


Best regards,


Kuhni.

Hello.

So, the car has 170,000 kilometers on the odometer.

I've already checked the timing, and it's correct!

The rattling noise is also present in overrun mode.

"Since the car has also been lacking power for some time, and it's not producing any smoke at all."
not even under full load, which is actually normal.

I just changed the oil, but the car doesn't actually need it.

I've also checked the fuel injectors and had them inspected, and they are okay.

The timing belt is also new.

"Since the error log shows 'ECU defective,' I assumed it was faulty and that it's no longer properly regulating the fuel injection timing when the engine is warm, which is why it's starting to make that strange clicking noise?!"

So, I replaced the control unit, but the error is still there, and the clicking sound is still present.

I haven't spent much money yet because I'm doing everything myself.

The question arises: will this ever come to an end?

Furthermore, the car still needs to go for its technical inspection (TÜV) this month, but it probably won't pass without proper performance, and with that clacking noise, it definitely won't.


I am still grateful for any advice.

Best regards, Christian.

Did you perform the error code reading yourself (using VAG-COM), or was it the workshop? If it was the workshop, which device did they use?
Using VAG COM or a VAG 1551, it is also possible to read additional values while the vehicle is in operation, and potentially perform an actuator test.
What about compression?

Best regards,
Herbert.

Hello,

wie sieht es denn mit der Bordspannung aus? Battery age???

Best regards, Roberto.