My timing maxes out at 25*adv... and when the car first fires up, hot or cold, the timing will max out at 34*adv until the knock sensor kicks on. When that knock sensor doesn't retard timing, damn does that car have some balls!

Anyone know what would happen if I just unplugged the knock sensor? Or does anyone know if the knock sensor is always on, as in always retarding some timing? Because I also have a blown water pump gasket, and the coolant never stays completely full... and I heard the bubbling of low coolant can also set off the knock sensor. Anyonw know if that is true?

Sorry wj, kinda stealing your thread..

hmm...actually I do remember something about the spark advance...umm, it was something resembling Don'* figures.

Hm... weird. Why more adv at lower throttle? I did notice that too, when the car fired up it had like 34*adv before the revs even dropped from the startup.

Just a thought: Get under the car and hit the cat with the palm of your hand and listen for a rattle, then the front and back heat shields on the exhaust manifolds.
The only rattles I have ever gotten on the 90 came from these areas. Think I put a large hose clamp around the rear manifold shield and the rattle went away.

make sure the car is cold when you do this

The desription sounds like a damper rattle. The rubber on the face of the damper hardens and cracks, and chunks can fall out. If it has never been changed, take a look at the face of the damper with a mirror or run your hand over it. If it is not smooth, odds are that is the rattle. Classic symtom is a rattle at idle that goes away when the rpms are increased.

Let me make this clear. This sound is coming from INSIDE the crank case. There is no doubt. You can feel it when you put weight on the engine when its idling and gets REAL loud when it revs down from 2k under no load. It sounds perfect underload.

You know, I think SSEBONNE has it.. I remember now that one of the heatshields was loose, both on my old headers [fixed], and on the new ones [installed; not fixed]... that very well could be it. And I have a hollowed cat... we got all the catalyst out, shouldn't rattle. And I bet that headshield makes enough of a rattle to set off the knock sensor just a little bit.

EDIT: now wj is making sense....:? I think come tomorrow I'm going to hold the heatshield while reproducing the sound. I know for a fact I have at least one loose heatshield. And I'll be sure to buffer my skin away from the hot heat shields .

My balancer is old... and i'm sure not smooth, but it'* tight [as in belt looseness]. Still should have some life left in it, and it really sounds like it'* coming right from the flywheel area.

Testing tomorrow.. I declare it. Everyone with this noise test away! tomorrow...

Ok.. One down, one to go.

WJC.. can you take a look at the harmonic balancer aka the dampener. A very good point is made with the mention of this as it sounds much like something internal when it starts getting bad.

Meanwhile.. please go get a vid of it. I'm sure that would help greatly.