M52 with M50 Intake Manifold Whistle Noise

[DiamondschwarzE30]

You just need a metal container with a lid. Place burning rag into it that's slightly wet. Low psi Compressed air in and air out is smokey. There's tons of videos on YouTube. Or the old spray break cleaner at it method.

Make sure the TB is propped open. I used rubber gloves to seal off the intake tube. Plus you can see it inflate to make sure it's pressurizing the intake. You only need a few psi.

Thanks for the ideas. I think I'm going to try and build one with a paint can and a cheap soldering iron. Might be useful to have in the future.

[DiamondschwarzE30]

Just spent 30 min checking for leaks with a smoke machine I made myself. No leaks could be found, but I did notice the system would not hold air pressure for very long, even with a rubber glove in place of the air filter. Not sure if that is normal or just air escaping through an open intake valve (one cylinder could be in a valve overlap position??). I could hear air hissing somewhere, but nothing smoked anywhere.

[ZekeTheSneak]

Air getting by the valves and most likely entering the exhaust. You could rotate the engine and see if that helps. I'm still interested in the outcome of this, good luck. Do you have an m50 tb to test out? The s52 TB is bigger then the opening on the m50 manifold. Maybe that's the noise.

[DiamondschwarzE30]

Air getting by the valves and most likely entering the exhaust. You could rotate the engine and see if that helps. I'm still interested in the outcome of this, good luck. Do you have an m50 tb to test out? The s52 TB is bigger then the opening on the m50 manifold. Maybe that's the noise.

I don't have a M50 throttle body to test out. Wish I would have pulled that from the junkyard with the manifold. Even so, that very well could be the source of the noise. Might rotate the engine and try again for vacuum leaks.

I'm also wondering if the adapter plate from the throttle body to the manifold could cause that too. The Kassel Performance kit uses a flat stainless steel plate between the throttle body and manifold. It instead uses 2 OEM gaskets on the manifold and throttle body instead of the special gasket found in the M50manifold.com kit. Might buy the special gasket and remove that plate.

[ZekeTheSneak]

Peak in there and see if it's overlapping? Might help to take the sharp angle off the plate with a file or sandpaper.

[DiamondschwarzE30]

Peak in there and see if it's overlapping? Might help to take the sharp angle off the plate with a file or sandpaper.

Sure enough...the opening in the throttle body plate is about 2mm smaller in diameter than the throttle body inner diameter. Seems like that could possibly create enough turbulence to make noise.

[ZekeTheSneak]

Yay wahoo hopefully that can be adjusted