Wastegate Question: Troubleshooting & Explained (08-05-2004, 22:03)

Hello fellow mechanics,

Since I'm experiencing a lack of power immediately after a cold start (for about 5 minutes) following humid nights, and this manifests as no turbo boost, I finally need to do something about it.

I assume that during a loss of power, the wastegate remains open and cannot be closed by the torsion spring. My question is now, in which area of the mechanism does excessive friction occur? A defect in the membrane itself can essentially be ruled out, since everything works perfectly when the engine is warm and after dry nights. This actually leaves only two possible causes:

1.) Rust in the area of the lever arm membrane chamber.
2.) Rust/coking in the area of the "rotating axis".

In the first case, it should be sufficient to push the lever out with a syringe and treat it with Caramba, or, in a more serious situation, replace the entire unit.

The second option would be expensive: a new loader. What do you think? Thank you in advance.

Hi there.

What does your N75 valve do? (The "klapper relay," which is the boost pressure control valve and is located above the brake booster.)

It might need to warm up before it starts working properly.

Although it should ideally regulate the boost pressure to 0.6 bar when there is no power applied (meaning it should instruct the turbocharger to self-regulate to 0.6 bar).

028 906 283 F is his name, and for 30 EUR, it will come to you .

Greetings.
Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

dieselmartin wrote:

What does your N75 do? (The "Klapper" relay, which regulates the boost pressure and is located above the brake booster). Perhaps it needs to warm up first before it starts working properly.

Hi Martin,

It might not sound too bad. I believe that this problem has been occurring since the valve was changed 1.5 years ago. Since I still have the receipt, I might stop by VW sometime .

"However, when I had the Zyko installed, I noticed that the wastegate felt a bit heavier than on our Audi 80, which had 240,000 km at the time. But the turbo was definitely brand new on my Passat (I've only owned the car for 1.6 years), because the turbocharger looked completely new and had no rust whatsoever (even the nuts for the downpipe were brand new)."

If I have time, I might also install the old solenoid valve sometime.