A vacuum is really only dangerous if it can suck in the whole body. Get close enough to the intake side of a jet engine and people are sometimes sucked in. Here we have a 2.5 inch hole with a good vacuum. What is a vacuum? It is the lack or absence of air pressure. So as the hand moves in front of the hole there is going to be some air moving in very fast until the hole is sealed. What then holds the hand there? The vacuum - No it is the weight of the air on the top of the hand - air pressure that holds the hand against the tube. The vacuum will remain until the engine stops creating it - it stalls. Then your hand will fall away from the tube. But you have a point that it can be dangerous, but not from the vacuum. You are sticking you hand quite close a fan which is turning very fast, and you are very close (with a body part) to an engine which is turning way past its design limits and could explode at any time. However, to save my engine, I would reach in there and stop it with the palm of my hand against the "U" tube. Better yet, make sure you understand the linkage and that it is hooked up correctly.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I've stopped mine a couple of times at idle with my hand on the turbo and it sucked a lot harder than I thought it would, like hurt and left a red mark for a couple of minutes. I sure as heck wouldn't try it on an engine that was turning 5000+ rpms. I could see that doing something nasty to your palm.

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Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo