Honda Repair: 94 civic EX engine noise, sucking, noise

Question
My 94 Civic EX has about 250,000 miles on it.  It has had all its regular maintenance, and recently had a new timing belt, water pump, and valve adjustment.

Right after the service above (on the way home), the engine began making noise. When the engine is warm (after running about 10-15 minutes), the engine makes a faint noise at 1000-1100 rpm only.  It sounds correct at all other levels.  The noise sounds like whistling, like when you swing a rope or pipe around quickly in a circle. The noise is staccato, with the whistle broken about 5 or 6 times per second.

I returned the car to the shop, where they replaced the water pump (thinking it was the water pump bearing), but it did not change the noise.  Now, the shop says they hear the noise, but don't hear a specific bearing or idler making noise, so they say "don't worry".  I'd like to know if anybody has a different take on it!

Is that the sort of noise that you would get if the valves were adjusted incorrectly?

Thanks,

Tim

Answer
Tim, that is a vacuum line sucking in air. Which means with 250K on your D16 the shop pinched a line that is sucking air. Fairly common since the more mileage you put on the car the more wear and tear the common parts of the motor break down. There is only a few lines on the motor but all should be replaced. Minus the fuel lines. I would not consider this a bearing. But I have heard that similarly, in my past and inspected the alternator. Which is another area to check. It is not valves. The only other it could be after all that and no help. Would be the timing belt tensioner. Hope this helps.