Oldsmobile/Buick Repair: 1988 Buick Park Ave Shaking, buick park ave, spark plug wires

Question
I have a 88 park ave. and every now and again if go to put the pedal down a little bit, the whole car will shake. I have heard problems to this such as bad spark plug wires, motor mounts, or the transmission. What do you believe is the Problem? Thanks


Answer
It could be any of those, but I had one shake real bad like you describe, and it had a broken valve spring. 3100 V6 engine. It has two springs on each valve, one inside the other, and one of them was broken on one cyl.
It showed up as a different compression reading on a test, and although it reached the same compression as the other cylinders, there was some different activity on the compression guage during the test.

Van