Head gasket replaced on 1997 Neon ringing noise

Hi,

I just replaced the leaky head gasket on my 97 Neon. It only took me 20
hours. yuk.

2.0 (C) SOHC with new head bolts.

Anyway it started right up and ran fine, but under light acceleration (load)
I get a quiet high pitched ringing noise. It occures at all rpms in any
gear any speed. No noise under heavy load. It's not a squeek. More like a
tuning fork??. Any thoughts.

Now for the bad news.
Please don't laugh. I have one bolt left over.

It's a 9.6 black 1/4 inch about 1 inch long. 15mm I think, real flat with a
built-in washer flange. I'ts just like the ones that hold the power
steering resevoir to the head.
It came off after the Intake manifold and before the motor mount, but I
can't put my finger on it.


Thanks..

 

sounds like a bolt from the manifold heat shield to me.

 

As far as I can tell there is one bolt top and bottom of the flange end on
the manifold. Those are 10mm. One on each side to hold the two peaces
together (10mm short), and 2 on the block that hold the air filter housing
(13mm). I got all those.

Thanks.