Hissing Sound From Bottom of Pistons

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.

--
Kent
1987 VW GTI 8V, original owner, 221,500+ miles

Yep it's normal. That's because of the ring end gaps being aorund .020 of an
inch.


"Kent" > wrote in message
...
> 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.
>
> --
> Kent
> 1987 VW GTI 8V, original owner, 221,500+ miles
>
>

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,

--
Kent
1987 VW GTI 8V, original owner, 221,500+ miles

"Woodchuck" > wrote in message
...
> Yep it's normal. That's because of the ring end gaps being aorund .020 of
an
> inch.
>
>
> "Kent" > wrote in message
> ...
> > 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.
> >
> > --
> > Kent
> > 1987 VW GTI 8V, original owner, 221,500+ miles
> >
> >
>
>
>