I recently did the thermal pellet mod on the ecentric shaft on my 86 s4 n/a. I did not push in the cluch like some of the threads said to do because I had not joined the forum yet. I pulled the front main pulley bolt by bumping the starter and using a long breaker bar to loosen the main bolt. I then shimed up the thermal pellet and put it back in with 60ft/lbs of torque. I have a shakey idle and i have checked for intake leaks and replaced the injectors also. The engine was tuned up about 3 weeks ago. The engine runs perfect and has good power. The rough idle is the only symptom, and it smooths out perfectly when i depress the gas a tad. I just wanted to know what are the signs of a sliped front bearing or a bad one.

 

http://www.mazdatrix.com/faq/pulley.htm

http://fc3spro.com/TECH/PROBLEMS/P1/...IDLE/rough.htm

 

If your front pully looks like this, then you have a problem:



Also, you will find little chunks of chewed up bearing in the oil pan.

 

Check your end play. If you have no end play then the bearing dropped and got crushed.

 

Thanks alot guys, I checked and all the belts line up properly. I am going to get a compression test done today just to eleminate the possibity that the engine is the problem. I have already searched and researched for a vacume leak and have found none. I have most of the emissions stuff blocked off. I used rtv black for the block off plates and also all new vacume lines for the rest of the ECU stuff. I just dont know whats going on. I did notice however the idle gets closer to normal with the BAC unplugged. And it does not stall when I turn the steering wheel or turn on any accessories with the BAC left unplugged. I just dont get it.