Whistling noise under load in Astra | VAUXHALL

Hello, as far as I know it doesn't have a turbo, otherwise it would be that. Then possibly an EGR problem.

Unfortunately, the car has neither a turbo nor an EGR valve.

It should have an EGR.

However, I would rather suspect a vacuum leak.

But it's difficult to judge noises if you haven't heard them yourself 😉

I wouldn't know where the EGR should be, see photo. Speed-related noises due to false air?

It should be located here. P.S. It doesn't look like you might know it from older Opel models 😉

The noise disappears when I shift into N and let it roll.

But don't be misled. I've never had a problem with an EGR making noise. The engine looks like it's done a few miles, take another close look at all the hoses, there are definitely plenty of hoses that you can't even see from above.

I'm guessing exhaust manifold, defective gasket, broken stud, crack

Can you simulate the sound when the vehicle is stationary?

A few km, yes... 352k km 😄. I've also never heard of an EGR making noise, only of the engine jerking or stalling. Okay, then I'll try to get some kind of smoke machine to find a possible leak. Because by just looking from above I couldn't see or find anything...

Unfortunately, only while driving. From about 100/110 km/h

Is it a constant whistle? Or a pulsating, RPM-dependent one?

Okay, please make a video.

I'll make a video later when my girlfriend has time to hold the phone 😄

Rises steadily between 100-120 & then the volume level remains.

I've also often sprayed the hoses, intake manifold gasket, etc. with brake cleaner. If the RPM changes at one point, you have a leak there. But be careful not to spray it on the exhaust or anything like that, so you don't burn the whole thing down or, even worse, yourself ☝🏼

I'll try that carefully later. Of course, when it's cold to minimize the risk.

Serpentine belt

Replaced the bearings after it tore. Unfortunately, the noise was already there before & is still there as described.