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[sandstoneolds20]

Hey guys,
So the other day my car started running really rough and it through a code. I took it to into the shop and the code said it was having a misfire on cylinder 3. The plug was fine. So I just kept driving it and finally one day I heard this hissing noise once and a while and finally it made this hissing noise and just died. It was almost like it was loosing compression. Anybody got any ideas?

[AGT]

1st idea...

Just because the plug was fine doesn't mean the electricity going to it was okay. The wire could be bad, etc.

2nd idea

Hissing could be a number of things. Did you check the coolant resevoir to see if it looked milky like a shake or did you see leakage around the manifold?