I'm in the process of replacing the timing belt, tensioner, and all the oil seals on the front of my engine. In the process, I have removed the oil pan. Tonight while working under the car, I turned the crank slightly using a wrench. When I do this, I hear a hissing sound that sounds like air escaping around the bottom of the pistons. The magnitude of the hissing sound really surprised me, as I thought the rings should do a better job of sealing the combustion chamber. Is what I'm hearing normal, or does this hissing sound suggest that my engine is in need of a rebuild? TIA.
Hissing Sound From Bottom of Pistons
Feb 13, 2005
2 Replies
Yep it's normal. That's because of the ring end gaps being aorund .020 of an inch.
Thanks Woodchuck; I'm glad to hear that this sound is considered normal. I'm definitely an amateur with these things, so the hissing sound was loud enough to make me think that something was seriously wrong with my rings. Lately the old GTI has been keeping me busy with deferred maintenance issues (like the seals I'm currently replacing), and every time I come across something I haven't noticed before, I imagine that the engine has finally gone south. I plan on doing the engine rebuild myself when the time finally comes (my first attempt at rebuilding an engine), but now is definitely not a good time for me to embark on such a time-consuming task.
Thanks again,
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