I have a 97 SE 5-speed with close to 80K. For the last 3 weeks or so, i have been hearing a knock-like noise inside the cockpit. First think I did was open the hood, but the noise was either not coming from under the hood, or the engine noise drowned it out.
The noise only occurs when the car is warmed up...the lower the idle, the more i hear it. It does not follow the rhythm of the engine, and once i have reached 1000 RPM or so I do not hear it.
One theory I have is that when I was battling a failed starter, I tried starting too much to the point that I flooded the engine...the engine flooded for sure and I have not changed my plugs yet. This would cause possible misfire, but I dont think thats it. The noise did start about the same time as the engine flooding, but im not for sure.
My second theory was presented to me by a guy who works at a ford quick-lane. He thought there was a vacuum hose behind my dash that may have gone bad...im not so sure about this.
Another idea is possible motor mounts. I do get a lot of clutch chatter, but im not sure the noise would be at all related. The noise happens clutch in and clutch out anyway.
I tested ECU, came up with KS code and nothing else, but engine light is not on.
I'm running out of ideas and remedies. Im doing the plugs on saturday but I dont expect that the noise will stop. Im pretty sure I am losing power. Oil has not burned or leaked whatsoever.
BTW i installed a FSTB right around this time....it rests on two vac hoses, but i dont think its pinching them
Any insight is appreciated, I'll kick myself before I go to the stealership!

 

If you got a KS code than that's what it is. You hear KNOCK and the KS code comes on, hmm. Engine knock shouldn't be that loud though. Change the KS...