Just a quick question, i have a 98 2.4l in a sunfire. It has a rough idle, miss, 13 inchs vac, timing chain is on. We ran a compresion test and found 1&4 to be 225# and 2&3 to be 100#. Seems like a head gasket to me but 100# is still alot of compression. What ... Login to read more.