Galaxy TDI: Engine Noise - Find the Source!

Galaxy 66Kw TDI, year 1996, chip tuning (approximately 120 hp), engine type 1Z.

I'm experiencing a problem: when I accelerate (while driving), I hear a hissing sound coming from the engine compartment. It starts around 1800 RPM and gets louder as the engine speed increases. I can also hear it when the car is stationary, but the engine noise is too loud to pinpoint the source. The hissing is only audible at higher RPMs when the car is stationary, and it's quieter than when the car is moving.

Visually, from what I can see and feel from above, I don't detect any leaks.

In the VAG-Com group 11, the second column shows, for example, 1530 mbar, and the third column shows 1280 mbar. I suspect that the first column displays the target pressure, and the third column displays the actual pressure. Is that correct (the program is unfortunately in English)? If that's the case, is the difference between the two values the hissing sound I'm hearing? CORRECT??

I also went to my dealer, and he said it could be either the intake manifold gasket, the exhaust manifold gasket, or the hoses from the turbo (although I think he probably knew where the whistling sound was coming from). -- They just want to make money, and a lot of it.

'However, I must also say that I've noticed for some time now that the car isn't as responsive as it used to be. I drive the car less often because my wife and the children need it. (And I have to say again, without generalizing, that sometimes women don't notice things; they might leave the ignition key in and the engine running, and everything seems fine to them. I've had a few instances where they didn't notice something, and I get in the car, start the engine, and realize that something's not right.) Well, as I said, not all women are like that!'


CU.

Hello,

I think we can safely ignore the exhaust manifold gasket. Otherwise, there would be quite a bit of mist in the engine compartment. You could check it with the engine running.
Let's take off the hood and give it a little gas. I'd start by checking the hose from the turbocharger to the intercooler. Then, I'd inspect the intercooler itself, and then move on to the engine. It should be relatively easy to find.

Unfortunately, the leak in my Galaxy was coming from the oil cooler. It was leaking at the points where the flanges are pressed onto the oil cooler. Replacing it was too expensive for me.

Best regards, Peter.