Serious knock

Sal Lubrano

Active Member
Apr 26, 2002
I am seeing almost 30 degrees of knock retard when I floor the GN from a 55mph cruise speed. The strange part is I get the knock before any boost is built up. Looking at the direct scan file the knock forms as the car is downshifting. If I get on it from a light it is clean all the way through. I was informed from one of our supporting vendors it probally is the lockup converter unlocking. I was also told this happens with quality converter as well and I should tap the brake to unlock the converter first, then stomp on it. Has anyone else encounter this problem and have you corrected it.
When you lift your foot off of the throttle, it unlocks. I have seen as much as 50 degrees of KR, but that was because the tires broke loose and spun for several feet. The sensers don't seem to like being shakin rapidly too much. I think if it was actual knock in the engine, we would both be either changing head gaskets by now or picking up parts.